EX-4.3



 Exhibit 4.3 

2.500% NOTES DUE 2034 

MERCK & CO., INC. 

Officers’ Certificate 

Pursuant to the resolutions (collectively, the “Resolutions”) of the Board of Directors of Merck & Co., Inc. (the
“Company”) adopted at meetings duly called and held on November 27, 2012 and March 26, 2013 (at which meetings a quorum was present and acting throughout), which authorized the Company to issue and sell its debt securities and
empowered an Authorized Officer (as defined in the Resolutions) to approve the form and terms of such debt securities, Mark E. McDonough, Vice President and Treasurer of the Company, as Authorized Officer under the Resolutions, and Katie E. Fedosz,
Senior Assistant Secretary, hereby approves and establishes under the Indenture, dated as of January 6, 2010 (the “Indenture”), between the Company and U.S. Bank Trust National Association, as Trustee (the “Trustee”), a
series of debt securities the terms of which are as follows: 
 1. The title of the debt securities of such series shall be
2.500% Notes due 2034 (the “2034 Notes”). 
 2. The aggregate principal amount of the 2034 Notes which may be
authenticated and delivered under the Indenture is initially limited to €500.0 million, except for 2034 Notes authenticated and delivered upon registration or transfer of, or in exchange for, or in lieu of, other 2034 Notes of the series
pursuant to Section 304, 305, 306, 906 or 1107 of the Indenture and except for any 2034 Notes which, pursuant to Section 303 of the Indenture, are deemed never to have been authenticated and delivered under the Indenture. 

3. The Company shall have the right from time to time, without the consent of the Holders of the 2034 Notes, to create and
issue additional notes with the same terms and conditions as the 2034 Notes except for the issue date, issue price and the first payment of interest thereon (“Additional Notes”), provided that if the Additional Notes are not fungible with
the previously outstanding 2034 Notes for U.S. federal income tax purposes, such Additional Notes will have a separate CUSIP, ISIN and Common Code. Additional Notes will be consolidated with and will form a single series with the previously
outstanding 2034 Notes. Any election by the Company to so increase such aggregate principal amount shall be evidenced by a certificate of an Authorized Officer or Authorized Officers. No Additional Notes may be issued if an Event of Default has
occurred or is continuing with respect to the 2034 Notes. 







 4. The 2034 Notes shall be issued in denominations of €100,000 and integral
multiples of €1,000 in excess thereof. 
 5. The proceeds to the Company (after deducting the underwriting discounts and
commissions but before deducting certain expenses payable by the Company in connection with the issuance of the 2034 Notes) shall be 98.189% of the aggregate principal amount of the 2034 Notes. 

6. The maturity date on which the principal of each of the 2034 Notes is payable shall be October 15, 2034 (the
“Stated Maturity”). 
 7. The 2034 Notes shall bear interest at the rate of 2.500% per annum from (and
including) October 15, 2014. Interest shall be payable on each Interest Payment Date and at the Stated Maturity. Interest payments shall be in the amount of interest accrued to, but excluding, the relevant Interest Payment Date or the Stated
Maturity, as applicable. 
 8. The Interest Payment Date for the 2034 Notes shall be October 15 of each year, commencing
on October 15, 2015, and the Regular Record Date for the 2034 Notes shall be the fifteenth calendar day before the next Interest Payment Date. 

If any Interest Payment Date, the Stated Maturity or Redemption Date for the 2034 Notes is not a Business Day, the Company
will make the payment for such Interest Payment Date, the Stated Maturity or Redemption Date on the next Business Day, but the Company will not be liable for any additional interest as a result of the delay in payment. 

“Business Day” means any Monday, Tuesday, Wednesday, Thursday or Friday which is not a day when banking institutions
are authorized or obligated by law or executive order to be closed in The City of New York or London and, for any place of payment outside of The City of New York or London, in such place of payment, and on which the Trans-European Automated
Real-time Gross Settlement Express Transfer system (the TARGET2 system), or any successor thereto, operates. 
 9. With
respect to the 2034 Notes, the Company will compute the amount of interest payable on the basis of (i) the actual number of days in the period for which interest is being calculated and (ii) the actual number of days from (and including)
the last date on which interest was paid on the 2034 Notes (or October 15, 2014, if no interest has been paid on the 2034 Notes) to (but excluding) the next scheduled Interest Payment Date. This payment convention is referred to as
ACTUAL/ACTUAL (ICMA) as defined in the rulebook of the International Capital Market Association. 
 10. The Paying Agent for
the 2034 Notes will be Elavon Financial Services Limited, UK Branch. The Security Registrar will be Elavon Financial Services Limited. Notwithstanding the foregoing, the Company may change the Paying Agent or Security Registrar, in accordance with
the terms of the Indenture and this Officers’ Certificate. 

  
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 11. The 2034 Notes will be redeemable in whole at any time or in part from time
to time, at the Company’s option, at a Redemption Price equal to the greater of (i) 100% of the principal amount of the 2034 Notes to be redeemed or (ii) the sum of the present values of the Remaining Scheduled Payments (as defined
below) (not including any portion of such payments of interest accrued as of the Redemption Date) discounted to the Redemption Date on an annual basis (ACTUAL/ACTUAL (ICMA)) at the applicable Comparable Government Bond Rate (as defined below), plus
15 basis points, plus any interest accrued but not paid to, but excluding, the Redemption Date. 
 On or after
July 15, 2034 (three months prior to the Stated Maturity of the 2034 Notes), the Company may redeem the 2034 Notes in whole at any time or in part from time to time, at the Company’s option, at a Redemption Price equal to 100% of
the principal amount of the 2034 Notes being redeemed, plus any interest accrued but not paid to, but excluding, the Redemption Date. 

“Comparable Government Bond Rate” means, with respect to any Redemption Date, the price, expressed as a percentage
(rounded to three decimal places, with 0.0005 being rounded upwards), at which the gross redemption yield on the 2034 Notes to be redeemed, if they were to be purchased at such price on the third Business Day prior to the Redemption Date, would be
equal to the gross redemption yield on such Business Day of the Comparable Government Bond (as defined below) on the basis of the middle market price of the Comparable Government Bond prevailing at 11:00 a.m. (London time) on such Business Day as
determined by an independent investment bank selected by the Company. 
 “Comparable Government Bond” means, in
relation to any Comparable Government Bond Rate calculation, at the discretion of an independent investment bank selected by the Company, a German federal government bond whose maturity is closest to the Stated Maturity of the 2034 Notes to be
redeemed, or if such independent investment bank in its discretion determines that such similar bond is not in issue, such other German federal government bond as such independent investment bank may, with the advice of three brokers of, and/or
market makers in, German federal government bonds selected by the Company, determine to be appropriate for determining the Comparable Government Bond Rate. 

“Remaining Scheduled Payments” means, with respect to the 2034 Notes to be redeemed, the remaining scheduled
payments of principal of and interest on the 2034 Notes that would be due after the related Redemption Date but for the redemption. If that Redemption Date is not an Interest Payment Date with respect to the 2034 Notes, the amount of the next
succeeding scheduled interest payment on the 2034 Notes will be reduced by the amount of interest accrued on the 2034 Notes to the related Redemption Date. 

  
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 Holders of 2034 Notes to be redeemed will receive notice thereof by first-class
mail at least 30 and not more than 60 days before the Redemption Date. 
 The principal amount of a 2034 Note remaining
outstanding after a redemption in part shall be €100,000 or an integral multiple of €1,000 in excess thereof. 

If fewer than all of the 2034 Notes are to be redeemed, the Trustee will select the particular 2034 Notes or portions thereof
for redemption from the outstanding 2034 Notes not previously called, pro rata or by lot, or in such other manner as the Company shall direct. 

Unless the Company defaults in payment of the Redemption Price, on and after the Redemption Date interest will cease to accrue
on the 2034 Notes or portions thereof called for redemption. 
 The 2034 Notes are also subject to redemption if certain
events occur involving United States taxation, as described under section 19 hereof. 
 12. Payment of the principal of (and
premium, if any) and interest on the 2034 Notes will be made in euros in immediately available funds upon surrender of such 2034 Notes at the office of the Paying Agent in London, UK. Payments of interest on any 2034 Notes (other than at the Stated
Maturity of such 2034 Notes) will be made by check mailed to the address of the Person entitled thereto as it appears in the Security Register or by wire transfer to such account as may have been appropriately designated in writing no later than the
relevant Regular Record Date to the Paying Agent by such Person. 
 13. The provisions on defeasance and covenant defeasance
in Article Thirteen of the Indenture shall apply to the 2034 Notes. However, for the 2034 Notes, any reference to “money” shall be replaced by “money (in euros)” and any reference to “U.S. Government Obligations” shall
be replaced by “Federal Republic of Germany Obligations” in that Article Thirteen. 
 “Federal Republic of
Germany obligations” means (1) securities that are direct obligations of the Federal Republic of Germany for the payment of which its full faith and credit is pledged or (2) obligations of a person controlled or supervised by and
acting as an agency or instrumentality of the Federal Republic of Germany, the payment of which is unconditionally guaranteed as a full faith and credit obligation by the Federal Republic of Germany, which, in either case under clauses (1) or
(2) are not callable or redeemable at the option of the issuer thereof. 
 14. In addition to the Events of Default
listed in Section 501 of the Indenture, for the 2034 Notes, there will be an Event of Default where the Company defaults in the payment of Additional Amounts on the 2034 Notes within 30 days after such payment is due. 

15. All payments of interest and principal, including payments made upon any redemption of the 2034 Notes, will be payable in
euros. If, on or after October 15, 2014, the euro is unavailable to the Company due to the imposition of exchange controls or 

  
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other circumstances beyond the Company’s control or if the euro is no longer being used by the then-member states of the European Monetary Union that have adopted the euro as their currency
or for the settlement of transactions by public institutions of or within the international banking community, then all payments in respect of the 2034 Notes will be made in U.S. dollars until the euro is again available to the Company or so used.
In such circumstances, the amount payable on any date in euros will be converted into U.S. dollars on the basis of the most recently available market exchange rate for euros. Any payment in respect of the 2034 Notes so made in U.S. dollars will not
constitute an Event of Default under the 2034 Notes or the Indenture. Neither the Trustee nor the Paying Agent shall have any responsibility for effecting such currency conversions. 

16. The Depository for such Book-Entry Securities shall be a common depositary. The 2034 Notes shall be issued in the form of
one or more Book-Entry Securities and registered in the name of the nominee of the common depositary for the accounts of Clearstream Banking, société anonyme, “Clearstream, Luxembourg,” and Euroclear
Bank S.A./N.V. 
 17. All payments of principal and interest in respect of the 2034 Notes will be made free and clear
of, and without deduction or withholding for or on account of, any present or future taxes, duties, assessments or other governmental charges of whatsoever nature imposed, levied, collected, withheld or assessed by the United States or any political
subdivision or taxing authority of or in the United States (collectively, “Taxes”), unless such withholding or deduction is required by law. 

In the event such withholding or deduction of Taxes is required by law, subject to the limitations described below, the
Company will pay to the holder of any 2034 Note that is not a U.S. Holder (as defined below) such additional amounts (“Additional Amounts”) as may be necessary in order that every net payment received by such holder of principal of or
interest or any other amount payable on the 2034 Notes (including upon redemption), after deduction or withholding for or on account of such Taxes, will not be less than the amount provided for in such 2034 Note to be then due and payable before
deduction or withholding for or on account of such Taxes. 
 A “U.S. Holder” is defined as any beneficial owner of
a 2034 Note that for United States federal income tax purposes is: (i) an individual citizen or resident of the United States; (ii) a corporation (or other entity classified as a corporation for these purposes) created or organized in or
under the laws of the United States, any State thereof or the District of Columbia; (iii) an estate, the income of which is subject to United States federal income taxation regardless of the source of that income; or (iv) a trust, if
(1) a United States court is able to exercise primary supervision over the trust’s administration and one or more “United States persons” (within the meaning of the Internal Revenue Code of 1986, as amended (the “Internal
Revenue Code”)) has the authority to control all of the trust’s substantial decisions, or (2) the trust has a valid election in effect under applicable Treasury regulations to be treated as a “United States person.” 

  
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 However, the Company’s obligation to pay Additional Amounts shall not apply
to: 
 (1) any Taxes which would not have been so imposed but for: 

(a) the existence of any present or former connection between such holder or beneficial owner (or between a fiduciary,
settlor, beneficiary, member or shareholder or other equity owner of, or a person having a power over, such holder or beneficial owner, if such holder or beneficial owner is an estate, a trust, a limited liability company, a partnership, a
corporation or other entity) and the United States, including, without limitation, such holder or beneficial owner (or such fiduciary, settlor, beneficiary, member, shareholder or other equity owner or person having such a power) being or having
been a citizen or resident or treated as a resident of the United States or being or having been engaged in a trade or business in the United States or being or having been present in the United States or having or having had a permanent
establishment in the United States; 
 (b) the failure of such holder or beneficial owner to comply with any certification,
information or other reporting requirement, if compliance is required under United States tax laws and regulations to establish entitlement to a partial or complete exemption from such Taxes (including, but not limited to, the requirement to provide
United States Internal Revenue Service Forms W-8BEN, Form W-8BEN-E, Form W-8ECI, or any subsequent versions thereof or successor thereto); or 

(c) such holder’s or beneficial owner’s present or former status as a personal holding company or a foreign personal
holding company with respect to the United States, as a controlled foreign corporation with respect to the United States, as a passive foreign investment company with respect to the United States, as a foreign tax exempt organization with respect to
the United States or as a corporation which accumulates earnings to avoid United States federal income tax; 
 (2) any Taxes
imposed by reason of the holder or beneficial owner: 
 (a) owning or having owned, directly or indirectly, actually or
constructively, 10% or more of the total combined voting power of all classes of the Company’s stock, as described in section 871(h)(3) of the Internal Revenue Code, 

(b) being a bank receiving interest described in section 881(c)(3)(A) of the Internal Revenue Code, or 

(c) being a controlled foreign corporation with respect to the United States that is related to the Company by stock
ownership; 
 (3) any Taxes which would not have been so imposed but for the presentation by the holder or beneficial owner
of such 2034 Note for payment on a date more than 30 days after the date on which such payment became due and payable or the date on which payment of the 2034 Note is duly provided for and notice is given to holders,


  
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whichever occurs later, except to the extent that the holder or beneficial owner would have been entitled to such Additional Amounts on presenting such 2034 Note on any date during such 30-day
period; 
 (4) any estate, inheritance, gift, sales, excise, transfer, personal property, wealth or similar Taxes; 

(5) any Taxes which are payable otherwise than by withholding from a payment on such 2034 Note; 

(6) any Taxes which are payable by a holder that is not the beneficial owner of the 2034 Note, or a portion of the 2034 Note,
or that is a fiduciary, partnership, limited liability company or other similar entity, but only to the extent that a beneficial owner, a beneficiary or settlor with respect to such fiduciary or member of such partnership, limited liability company
or similar entity would not have been entitled to the payment of an additional amount had such beneficial owner, settlor, beneficiary or member received directly its beneficial or distributive share of the payment; 

(7) any Taxes required to be withheld by any paying agent from any payment on any 2034 Note, if such payment can be made
without such withholding by at least one other paying agent; 
 (8) any Taxes required to be withheld or deducted where such
withholding or deduction is imposed pursuant to European Council Directive 2003/48/EC on the taxation of savings income or any law implementing or complying with, or introduced in order to conform to, such European Council Directive; 

(9) any Taxes imposed under sections 1471 through 1474 of the Internal Revenue Code (or any amended or successor provisions),
any current or future Treasury regulations or official interpretations thereof, any agreement entered into pursuant to section 1471(b) of the Internal Revenue Code or any fiscal or regulatory legislation, rules or practices adopted pursuant to any
intergovernmental agreement entered into in connection with the implementation of such sections of the Internal Revenue Code; or 

(10) any combination of items (1), (2), (3), (4), (5), (6), (7), (8) and (9). 

For purposes of this section, the acquisition, ownership, enforcement, or holding of or the receipt of any payment with respect
to a 2034 Note will not constitute a connection (i) between the holder or beneficial owner and the United States or (ii) between a fiduciary, settlor, beneficiary, member or shareholder or other equity owner of, or a person having a power
over, such holder or beneficial owner if such holder or beneficial owner is an estate, a trust, a limited liability company, a partnership, a corporation or other entity and the United States. 

  
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 Any reference in the 2034 Notes or Indenture to principal or interest or other
payment on the 2034 Notes shall be deemed to refer also to Additional Amounts which may be payable under the provisions of this section. 

The Company will pay all stamp and other duties, if any, which may be imposed by the United States or any political subdivision
thereof or taxing authority therein with respect to the issuance of the 2034 Notes pursuant to this offering. 
 Except as
specifically provided in the 2034 Notes, the Company will not be required to make any payment with respect to any tax, duty, assessment or other governmental charge imposed by any government or any political subdivision or taxing authority of or in
the United States. 
 18. The Company undertakes that, to the extent permitted by law, the Company will maintain a Paying
Agent in a member state of the European Union (if any) that will not require withholding or deduction of tax pursuant to European Council Directive 2003/48/EC on the taxation of savings income or any law implementing or complying with, or introduced
in order to conform to, such European Council Directive. 
 19. The 2034 Notes may be redeemed at the Company’s option,
in whole but not in part, at a Redemption Price equal to 100% of the principal amount of the 2034 Notes to be redeemed, together with interest accrued and unpaid to the Redemption Date, at any time, on giving not less than 30 nor more than 60
days’ notice, if 
 (1) the Company has or will become obligated to pay Additional Amounts as a result of any change in
or amendment to the laws, regulations or rulings of the United States or any political subdivision or any taxing authority of or in the United States affecting taxation, or any change in or amendment to an official application, interpretation,
administration or enforcement of such laws, regulations or rulings, which change or amendment is announced or becomes effective on or after October 6, 2014, provided the Company reasonably determines that such obligation cannot be
avoided by the Company’s taking reasonable measures available to the Company without significant difficulty, cost or expense, or 

(2) any action shall have been taken by a taxing authority, or any action has been brought in a court of competent
jurisdiction, in the United States or any political subdivision or taxing authority of or in the United States, including any of those actions specified in (1) above, whether or not such action was taken or brought with respect to the Company,
or any change, clarification, amendment, application or interpretation of such laws, regulations or rulings shall be officially proposed, in any such case on or after October 6, 2014, which results in a substantial likelihood that the Company
will be required to pay Additional Amounts on the next Interest Payment Date. 
 However, no such notice of redemption shall
be given earlier than 90 days prior to the earliest date on which the Company would be, in the case of a redemption for the reasons specified in (1) above, or there would be a substantial likelihood that the Company would be, in the case of a
redemption for the reasons specified in (2) above, 

  
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obligated to pay such Additional Amounts if a payment in respect of the 2034 Notes were then due and, at the time such notification of redemption is given, such circumstance remains in effect.

 Prior to the publication of any notice of redemption pursuant to this section, in the case of a redemption for the reasons
specified in (1) or (2) above, the Company will deliver to the Trustee under the Indenture: 
 (i) a certificate
signed by one of the Company’s duly authorized officers stating that the Company is entitled to effect such redemption and setting forth a statement of facts showing that the conditions precedent to the Company’s right so to redeem have
occurred, and 
 (ii) a written opinion of independent legal counsel of recognized standing to the effect that the Company
has or will become obligated to pay such Additional Amounts as a result of such change or amendment or that there is a substantial likelihood that the Company will be required to pay such Additional Amounts as a result of such action or proposed
change, clarification, amendment, application or interpretation, as the case may be. 
 Such notice, once delivered by the
Company to the Trustee, will be irrevocable. 
 20. The form of the 2034 Notes attached hereto as Annex A is hereby
approved. 
 Capitalized terms used herein and not otherwise defined herein have the meanings specified in the Indenture.


  
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 IN WITNESS WHEREOF, we have hereunto signed our names this 15th day of October, 2014. 

 

			
	By:	 	 /s/ Mark E. McDonough

		 	Mark E. McDonough
		 	Vice President and Treasurer
		
	By:	 	 /s/ Katie E. Fedosz

		 	Katie E. Fedosz
		 	Senior Assistant Secretary









 Annex A 
  

					
	REGISTERED	 		  	REGISTERED
	No. R-1	 		  	PRINCIPAL AMOUNT: €500,000,000
	CUSIP NO.: 58933Y AM7	 		  	
	ISIN NO.: XS1028941893	 		  	
	COMMON CODE: 102894189	 		  	

 MERCK & CO., INC. 

2.500% NOTES DUE 2034 
 This
Security is a Book-Entry Security within the meaning of the Indenture referred to on the reverse hereof and is registered in the name of USB Nominees (UK) Limited, as nominee of Elavon Financial Services Limited, common depository for the accounts
of Clearstream Banking, société anonyme, Luxembourg, and Euroclear Bank SA/NV, as operator of the Euroclear System (the “Depository”). This Security is exchangeable for Securities registered in the name of a Person other than
the Depository or its nominee only in the limited circumstances described in the Indenture and this Security may not be transferred except as a whole by the Depository to a nominee of the Depository or by a nominee of the Depository to the
Depository or another nominee of the Depository. 
 Unless this Certificate is presented by an authorized representative of the Depository
to the Company or its agent for registration of transfer, exchange or payment, and any Certificate issued is registered in the name of USB Nominees (UK) Limited or in such other name as is requested by an authorized representative of the Depository
(and any payment hereon is made to USB Nominees (UK) Limited or to such other entity as is requested by an authorized representative of Depository), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL in
as much as the registered owner hereof, USB Nominees (UK) Limited, has an interest herein. 







 Merck & Co., Inc., a New Jersey corporation (hereinafter called the “Company”,
which term includes any successor corporation under the Indenture hereinafter referred to), for value received, hereby promises to pay to USB Nominees (UK) Limited, as nominee for the Depository, or registered assigns, the principal sum of Five
Hundred Million Euros (€500,000,000) on October 15, 2034 (the “Stated Maturity”), and to pay interest thereon from and including October 15, 2014 or from the most recent Interest Payment Date to which interest has been
paid or duly provided for, on October 15 of each year and at the Stated Maturity, commencing on October 15, 2015, at a rate per annum of 2.500%, until the principal hereof is paid or made available for payment, and (to the extent that the
payment of such interest shall be legally enforceable) at the interest rate specified above on any overdue principal and premium and on any overdue installment of interest. The interest so payable, and punctually paid or duly provided for, on any
Interest Payment Date will, as provided in such Indenture, be paid to the Person in whose name this Security (or one or more Predecessor Securities) is registered at the close of business on the Regular Record Date for such interest, which shall be
the fifteenth calendar day before the next Interest Payment Date. Any such interest not so punctually paid or duly provided for will forthwith cease to be payable to the Holder on such Regular Record Date and may either be paid to the Person in
whose name this Security (or one or more Predecessor Securities) is registered at the close of business on a Special Record Date for the payment of such Defaulted Interest to be fixed by the Trustee, notice whereof shall be given to Holders of
Securities of this series not less than 10 days prior to such Special Record Date, or be paid at any time in any other lawful manner not inconsistent with the requirements of any securities exchange on which the Securities of this series may be
listed, and upon such notice as may be required by such exchange, all as more fully provided in said Indenture. 
 The Company will at all
times appoint and maintain a Paying Agent (which may be the Trustee) authorized by the Company to pay the principal of (and premium, if any) or interest on any Securities of this series on behalf of the Company and having an office or agency (the
“Paying Agent Office”), where Securities of this series may be presented or surrendered for payment and where notices, designations or requests in respect of payments with respect to Securities of this series may be served. The Company has
initially appointed Elavon Financial Services Limited, UK Branch as such Paying Agent, with the Paying Agent Office currently at 125 Old Broad Street, London, EC2N 1AR United Kingdom. The Company will give prompt written notice to the Trustee of any
change in such appointment. In addition, the Company undertakes that, to the extent permitted by law, the Company will maintain a Paying Agent in a member state of the European Union (if any) that will not require withholding or deduction of tax
pursuant to European Council Directive 2003/48/EC on the taxation of savings income or any law implementing or complying with, or introduced in order to conform to, such European Council Directive. 

Payment of the principal of (and premium, if any) and interest on this Security will be made in euros in immediately available funds upon
surrender of such Security at the office of the Paying Agent in London, UK. Payments of interest on any Security of this series (other than at the Stated Maturity of such Security) will be made by check mailed to the address of the Person entitled
thereto as it appears in the Security Register or by wire transfer to such account as may have been appropriately designated in writing no later than the relevant Regular Record Date to the Paying Agent by such Person. 

  
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 Reference is hereby made to the further provisions of this Security set forth on the reverse
hereof, which further provisions shall for all purposes have the same effect as if set forth at this place. 

  
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 Unless the certificate of authentication hereon has been executed by the Trustee referred to on
the reverse hereof by manual signature, this Security shall not be entitled to any benefit under the Indenture or be valid or obligatory for any purpose. 

[Signature page follows] 

  
 4 








 IN WITNESS WHEREOF, the Company has caused this instrument to be duly executed under its
corporate seal. 
 Dated: October 15, 2014 
  

					
	MERCK & CO., INC.
		
	By:	 	  

		 	Name:	 	Mark E. McDonough
		 	Title:	 	Vice President and Treasurer


  

	
	Attest:
	
	  


 CERTIFICATE OF AUTHENTICATION 

This is one of the Securities of the series designated herein referred to in the within-mentioned Indenture. 

 

			
	U.S. BANK TRUST NATIONAL ASSOCIATION,
	      As Trustee
		
	By:	 	  

		 	Authorized Officer


  
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 [REVERSE OF SECURITY] 

MERCK & CO., INC. 

2.500% NOTES DUE 2034 
 This
Security is one of a duly authorized issue of securities of the Company (herein called the “Securities”), issued and to be issued in one or more series under an Indenture, dated as of January 6, 2010, as amended and supplemented
(herein called the “Indenture”), between the Company and U.S. Bank Trust National Association, as Trustee (herein called the “Trustee”, which term includes any successor trustee under the Indenture), to which Indenture and all
indentures supplemental thereto reference is hereby made for a statement of the respective rights, limitations of rights, duties and immunities thereunder of the Company, the Trustee and the Holders of the Securities and of the terms upon which the
Securities are, and are to be, authenticated and delivered. 
 The terms of the Securities include those stated in the Indenture and in the
Officers’ Certificate dated October 15, 2014 (the “Officers’ Certificate”). This Security is subject to the terms in the Indenture and the Officers’ Certificate, and Holders are referred to the Indenture and the
Officers’ Certificate for a statement of such terms. All terms used but not defined in this Security which are defined in the Indenture or in the Officers’ Certificate shall have the meanings assigned to them in the Indenture or
Officers’ Certificate, as applicable. 
 This Security is one of the series designated on the face hereof. The aggregate principal
amount of such series is €500,000,000. 
 The Company shall have the right from time to time, without the consent of the Holders of the
Securities, to create and issue additional securities with the same terms and conditions as the Securities except for the issue date, issue price and the first payment of interest thereon (“Additional Securities”), provided that if the
Additional Securities are not fungible with the previously outstanding Securities for U.S. federal income tax purposes, such Additional Securities will have a separate CUSIP, ISIN and Common Code. Additional Securities will be consolidated with and
will form a single series with the previously outstanding Securities. Any election by the Company to so increase such aggregate principal amount shall be evidenced by a certificate of an Authorized Officer or Authorized Officers. No Additional
Securities may be issued if an Event of Default has occurred or is continuing with respect to the Securities. 
 If any Interest Payment
Date, Stated Maturity or Redemption Date for the Securities is not a Business Day, the Company will make the payment for such Interest Payment Date, Stated Maturity or Redemption Date on the next Business Day, but the Company will not be liable for
any additional interest as a result of the delay in payment. 
 “Business Day” means any Monday, Tuesday, Wednesday, Thursday or
Friday which is not a day when banking institutions are authorized or obligated by law or executive order to be closed in The City of New York or London and, for any place of payment outside of The City of New York or London, in such place of
payment, and on which the Trans-European Automated Real-time Gross Settlement Express Transfer system (the TARGET2 system), or any successor thereto, operates. 







 With respect to the Securities, the Company will compute the amount of interest payable on the
basis of (i) the actual number of days in the period for which interest is being calculated and (ii) the actual number of days from (and including) the last date on which interest was paid on the Securities (or October 15, 2014, if no
interest has been paid on the Securities) to (but excluding) the next scheduled Interest Payment Date. This payment convention is referred to as ACTUAL/ACTUAL (ICMA) as defined in the rulebook of the International Capital Market Association. 

This Security is not subject to any sinking fund. 

The Securities will be redeemable in whole at any time or in part from time to time, at the Company’s option, at a Redemption Price equal
to the greater of (i) 100% of the principal amount of the Securities to be redeemed or (ii) the sum of the present values of the Remaining Scheduled Payments (as defined below) (not including any portion of such payments of interest
accrued as of the Redemption Date) discounted to the Redemption Date on an annual basis (ACTUAL/ACTUAL (ICMA)) at the applicable Comparable Government Bond Rate (as defined below), plus 15 basis points, plus any interest accrued but not paid to, but
excluding, the Redemption Date. 
 On or after July 15, 2034 (three months prior to the Stated Maturity of the Securities),
the Company may redeem the Securities in whole at any time or in part from time to time, at the Company’s option, at a Redemption Price equal to 100% of the principal amount of the Securities being redeemed, plus any interest accrued but not
paid to, but excluding, the Redemption Date. 
 “Comparable Government Bond Rate” means, with respect to any Redemption Date, the
price, expressed as a percentage (rounded to three decimal places, with 0.0005 being rounded upwards), at which the gross redemption yield on the Securities to be redeemed, if they were to be purchased at such price on the third Business Day prior
to the Redemption Date, would be equal to the gross redemption yield on such Business Day of the Comparable Government Bond (as defined below) on the basis of the middle market price of the Comparable Government Bond prevailing at 11:00 a.m. (London
time) on such Business Day as determined by an independent investment bank selected by the Company. 
 “Comparable Government
Bond” means, in relation to any Comparable Government Bond Rate calculation, at the discretion of an independent investment bank selected by the Company, a German federal government bond whose maturity is closest to the Stated Maturity of the
Securities to be redeemed, or if such independent investment bank in its discretion determines that such similar bond is not in issue, such other German federal government bond as such independent investment bank may, with the advice of three
brokers of, and/or market makers in, German federal government bonds selected by the Company, determine to be appropriate for determining the Comparable Government Bond Rate. 

  
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 “Remaining Scheduled Payments” means, with respect to the Securities to be redeemed,
the remaining scheduled payments of principal of and interest on the Security that would be due after the related Redemption Date but for the redemption. If that Redemption Date is not an Interest Payment Date with respect to a Security, the amount
of the next succeeding scheduled interest payment on the Security will be reduced by the amount of interest accrued on the Security to the related Redemption Date. 

Holders of Securities to be redeemed will receive notice thereof by first-class mail at least 30 and not more than 60 days before the
Redemption Date. 
 The principal amount of this Security remaining outstanding after a redemption in part shall be €100,000 or an
integral multiple of €1,000 in excess thereof. 
 If fewer than all of the Securities are to be redeemed, the Trustee will select the
particular Securities or portions thereof for redemption from the outstanding Securities not previously called, pro rata or by lot, or in such other manner as the Company shall direct. 

Unless the Company defaults in payment of the Redemption Price, on and after the Redemption Date interest will cease to accrue on the
Securities or portions thereof called for redemption. 
 The Securities are also subject to redemption if certain events occur involving
United States taxation, as described below. 
 All payments of principal and interest in respect of the Securities will be made free and
clear of, and without deduction or withholding for or on account of, any present or future taxes, duties, assessments or other governmental charges of whatsoever nature imposed, levied, collected, withheld or assessed by the United States or any
political subdivision or taxing authority of or in the United States (collectively, “Taxes”), unless such withholding or deduction is required by law. 

In the event such withholding or deduction of Taxes is required by law, subject to the limitations described below, the Company will pay to
the holder of any Security that is not a U.S. Holder (as defined below) such additional amounts (“Additional Amounts”) as may be necessary in order that every net payment received by such holder of principal of or interest or any other
amount payable on the Securities (including upon redemption), after deduction or withholding for or on account of such Taxes, will not be less than the amount provided for in such Note to be then due and payable before deduction or withholding for
or on account of such Taxes. 
 A “U.S. Holder” is defined as any beneficial owner of a Security that for United States federal
income tax purposes is: (i) an individual citizen or resident of the United States; (ii) a corporation (or other entity classified as a corporation for these purposes) created or organized in or under the laws of the United States, any
State thereof or the District of Columbia; (iii) an estate, the income of which is subject to United States federal income taxation regardless of the source of that income; or (iv) a trust, if (1) a United States court is able to
exercise primary supervision over the trust’s administration and one or more “United States persons” (within the meaning of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code”)) has the authority to
control all of the trust’s substantial decisions, or (2) the trust has a valid election in effect under applicable U.S. Treasury regulations to be treated as a “United States person.” 

  
 3 








 However, the Company’s obligation to pay Additional Amounts shall not apply to: 

(1) any Taxes which would not have been so imposed but for: 

(a) the existence of any present or former connection between such holder or beneficial owner (or between a fiduciary, settlor,
beneficiary, member or shareholder or other equity owner of, or a person having a power over, such holder or beneficial owner, if such holder or beneficial owner is an estate, a trust, a limited liability company, a partnership, a corporation or
other entity) and the United States, including, without limitation, such holder or beneficial owner (or such fiduciary, settlor, beneficiary, member, shareholder or other equity owner or person having such a power) being or having been a citizen or
resident or treated as a resident of the United States or being or having been engaged in a trade or business in the United States or being or having been present in the United States or having or having had a permanent establishment in the United
States; 
 (b) the failure of such holder or beneficial owner to comply with any certification, information or other
reporting requirement, if compliance is required under United States tax laws and regulations to establish entitlement to a partial or complete exemption from such Taxes (including, but not limited to, the requirement to provide United States
Internal Revenue Service Forms W-8BEN, Form W-8BEN-E, Form W-8ECI, or any subsequent versions thereof or successor thereto); or 

(c) such holder’s or beneficial owner’s present or former status as a personal holding company or a foreign personal
holding company with respect to the United States, as a controlled foreign corporation with respect to the United States, as a passive foreign investment company with respect to the United States, as a foreign tax exempt organization with respect to
the United States or as a corporation which accumulates earnings to avoid United States federal income tax; 
 (2) any Taxes imposed by
reason of the holder or beneficial owner: 
 (a) owning or having owned, directly or indirectly, actually or constructively,
10% or more of the total combined voting power of all classes of the Company’s stock, as described in section 871(h)(3) of the Internal Revenue Code, 

(b) being a bank receiving interest described in section 881(c)(3)(A) of the Internal Revenue Code, or 

(c) being a controlled foreign corporation with respect to the United States that is related to the Company by stock ownership;


  
 4 








 (3) any Taxes which would not have been so imposed but for the presentation by the holder or
beneficial owner of such Security for payment on a date more than 30 days after the date on which such payment became due and payable or the date on which payment of the Security is duly provided for and notice is given to holders, whichever occurs
later, except to the extent that the holder or beneficial owner would have been entitled to such Additional Amounts on presenting such Security on any date during such 30-day period; 

(4) any estate, inheritance, gift, sales, excise, transfer, personal property, wealth or similar Taxes; 

(5) any Taxes which are payable otherwise than by withholding from a payment on such Security; 

(6) any Taxes which are payable by a holder that is not the beneficial owner of the Security, or a portion of the Security, or that is a
fiduciary, partnership, limited liability company or other similar entity, but only to the extent that a beneficial owner, a beneficiary or settlor with respect to such fiduciary or member of such partnership, limited liability company or similar
entity would not have been entitled to the payment of an additional amount had such beneficial owner, settlor, beneficiary or member received directly its beneficial or distributive share of the payment; 

(7) any Taxes required to be withheld by any paying agent from any payment on any Security, if such payment can be made without such
withholding by at least one other paying agent; 
 (8) any Taxes required to be withheld or deducted where such withholding or deduction is
imposed pursuant to European Council Directive 2003/48/EC on the taxation of savings income or any law implementing or complying with, or introduced in order to conform to, such European Council Directive; 

(9) any Taxes imposed under sections 1471 through 1474 of the Internal Revenue Code (or any amended or successor provisions), any current or
future Treasury regulations or official interpretations thereof, any agreement entered into pursuant to section 1471(b) of the Internal Revenue Code or any fiscal or regulatory legislation, rules or practices adopted pursuant to any
intergovernmental agreement entered into in connection with the implementation of such sections of the Internal Revenue Code; or 
 (10) any
combination of items (1), (2), (3), (4), (5), (6), (7), (8) and (9). 
 For purposes of this section, the acquisition, ownership,
enforcement, or holding of or the receipt of any payment with respect to a Security will not constitute a connection (i) between the holder or beneficial owner and the United States or (ii) between a fiduciary, settlor, beneficiary, member
or shareholder or other equity owner of, or a person having a power over, such holder or beneficial owner if such holder or beneficial owner is an estate, a trust, a limited liability company, a partnership, a corporation or other entity and the
United States. 

  
 5 








 Any reference in the Securities or Indenture to principal or interest or other payment on the
Securities shall be deemed to refer also to Additional Amounts which may be payable under the provisions of this section. 
 The Company
will pay all stamp and other duties, if any, which may be imposed by the United States or any political subdivision thereof or taxing authority therein with respect to the issuance of the Securities pursuant to this offering. 

Except as specifically provided in the Securities, the Company will not be required to make any payment with respect to any tax, duty,
assessment or other governmental charge imposed by any government or any political subdivision or taxing authority of or in the United States. 

The Securities may be redeemed at the Company’s option, in whole but not in part, at a Redemption Price equal to 100% of the principal
amount of the Securities to be redeemed, together with interest accrued and unpaid to the Redemption Date, at any time, on giving not less than 30 nor more than 60 days’ notice, if 

(1) the Company has or will become obligated to pay Additional Amounts as a result of any change in or amendment to the laws, regulations or
rulings of the United States or any political subdivision or any taxing authority of or in the United States affecting taxation, or any change in or amendment to an official application, interpretation, administration or enforcement of such laws,
regulations or rulings, which change or amendment is announced or becomes effective on or after October 6, 2014, provided the Company reasonably determines that such obligation cannot be avoided by the Company’s taking reasonable
measures available to the Company without significant difficulty, cost or expense, or 
 (2) any action shall have been taken by a taxing
authority, or any action has been brought in a court of competent jurisdiction, in the United States or any political subdivision or taxing authority of or in the United States, including any of those actions specified in (1) above, whether or
not such action was taken or brought with respect to the Company, or any change, clarification, amendment, application or interpretation of such laws, regulations or rulings shall be officially proposed, in any such case on or after October 6,
2014, which results in a substantial likelihood that the Company will be required to pay Additional Amounts on the next Interest Payment Date. 

However, no such notice of redemption shall be given earlier than 90 days prior to the earliest date on which the Company would be, in the
case of a redemption for the reasons specified in (1) above, or there would be a substantial likelihood that the Company would be, in the case of a redemption for the reasons specified in (2) above, obligated to pay such Additional Amounts
if a payment in respect of the Securities were then due and, at the time such notification of redemption is given, such circumstance remains in effect. 

  
 6 








 Prior to the publication of any notice of redemption pursuant to this section, in the case of a
redemption for the reasons specified in (1) or (2) above, the Company will deliver to the Trustee under the Indenture: 
 (i) a
certificate signed by one of the Company’s duly authorized officers stating that the Company is entitled to effect such redemption and setting forth a statement of facts showing that the conditions precedent to the Company’s right so to
redeem have occurred, and 
 (ii) a written opinion of independent legal counsel of recognized standing to the effect that the Company has
or will become obligated to pay such Additional Amounts as a result of such change or amendment or that there is a substantial likelihood that the Company will be required to pay such Additional Amounts as a result of such action or proposed change,
clarification, amendment, application or interpretation, as the case may be. 
 Such notice, once delivered by the Company to the Trustee,
will be irrevocable. 
 All payments of interest and principal, including payments made upon any redemption of the Securities, will be
payable in euros. If, on or after October 15, 2014, the euro is unavailable to the Company due to the imposition of exchange controls or other circumstances beyond the Company’s control or if the euro is no longer being used by the
then-member states of the European Monetary Union that have adopted the euro as their currency or for the settlement of transactions by public institutions of or within the international banking community, then all payments in respect of the
Securities will be made in U.S. dollars until the euro is again available to the Company or so used. In such circumstances, the amount payable on any date in euros will be converted into U.S. dollars on the basis of the most recently available
market exchange rate for euros. Any payment in respect of the Securities so made in U.S. dollars will not constitute an Event of Default under the Indenture. Neither the Trustee nor the Paying Agent shall have any responsibility for effecting such
currency conversions. 
 In addition to the Events of Default listed in Section 501 of the Indenture, for the Securities, there will be
an Event of Default where the Company defaults in the payment of Additional Amounts on the Securities within 30 days after such payment is due. If an Event of Default with respect to the Securities of this series shall occur and be continuing, the
principal of the Securities of this series may be declared due and payable in the manner and with the effect provided in the Indenture. 

The provisions on defeasance and covenant defeasance in Article Thirteen of the Indenture shall apply to the Securities. However, for the
Securities, any reference to “money” shall be replaced by “money (in euros)” and any reference to “U.S. Government Obligations” shall be replaced by “Federal Republic of Germany Obligations” in that Article
Thirteen. 
 “Federal Republic of Germany obligations” means (1) securities that are direct obligations of the Federal
Republic of Germany for the payment of which its full faith and 

  
 7 








 
credit is pledged or (2) obligations of a person controlled or supervised by and acting as an agency or instrumentality of the Federal Republic of Germany, the payment of which is
unconditionally guaranteed as a full faith and credit obligation by the Federal Republic of Germany, which, in either case under clauses (1) or (2) are not callable or redeemable at the option of the issuer thereof. 

The Indenture permits, with certain exceptions as therein provided, the amendment thereof and the modification of the rights and obligations
of the Company and the rights of the Holders of the Securities of each series to be affected under the Indenture at any time by the Company and the Trustee with the consent of the Holders of a majority in principal amount of the Securities at the
time Outstanding of each series to be affected. The Indenture also contains provisions permitting the Holders of specified percentages in principal amount of the Securities of each series at the time Outstanding, on behalf of the Holders of all
Securities of such series, to waive compliance by the Company with certain provisions of the Indenture and certain past defaults under the Indenture and their consequences. Any such consent or waiver by the Holder of this Security shall be
conclusive and binding upon such Holder and upon all future Holders of this Security and of any Security issued upon the registration of transfer hereof or in exchange thereof or in lieu hereof, whether or not notation of such consent or waiver is
made upon this Security. 
 No reference herein to the Indenture and no provision of this Security or of the Indenture shall alter or impair
the obligation of the Company, which is absolute and unconditional, to pay the principal of and any premium and interest on this Security at the times, place and rate, and in the coin or currency, herein prescribed. 

As provided in the Indenture and subject to certain limitations therein set forth, the transfer of this Security is registrable in the
Security Register, upon surrender of this Security for registration of transfer at the office or agency of the Company in any place where the principal of (and premium, if any) and interest on this Security are payable, duly endorsed by, or
accompanied by a written instrument of transfer in form satisfactory to the Company and the Security Registrar duly executed by, the Holder hereof or his attorney duly authorized in writing, and thereupon one or more new Securities of this series
and of like tenor, of authorized denominations and for the same aggregate principal amount, will be issued to the designated transferee or transferees. 

The Securities of this series are issuable only in registered form without coupons in denominations of €100,000 and integral multiples of
€1,000 in excess thereof. As provided in the Indenture and subject to certain limitations therein set forth, Securities of this series are exchangeable for a like aggregate principal amount of Securities of this series and of like tenor of a
different authorized denomination, as requested by the Holder surrendering the same. 
 No service charge shall be made for any such
registration of transfer or exchange, but the Company may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection therewith. 

Prior to due presentment of this Security for registration of transfer, the Company, the Trustee and any agent of the Company or the Trustee
may treat the Person in whose name 

  
 8 








 
this Security is registered as the owner hereof for all purposes, whether or not this Security be overdue, and neither the Company, the Trustee nor any such agent shall be affected by notice to
the contrary. 

  
 9 








 ABBREVIATIONS 

The following abbreviations, when used in the inscription on the face of the within Security, shall be construed as though they were written
out in full according to applicable laws or regulations. 
  

									
	TEN COM	 	-            	 	as tenants in common	  	
	  
 TEN ENT
	 	  

-            
	 	  
 as tenants by the entireties
	  	
	  
 JT TEN
	 	  

-            
	 	  
 as joint tenants with right of survivorship and not as
tenants in common
	  	
			
	UNIF GIFT MIN ACT -	  	                                   Custodian 
                        	  	
		 		 		  	          (Cust)                           
     (Minor)	  	
				
		 		 	under Uniform Gifts to Minors Act	  	
				
		 		 	  
	  	
		 		 	(State)	  	
				
		 		 	 Additional abbreviations may also be used though not in the above list.
	  	
				
		 		 	  
	  	


  
 10 








 ASSIGNMENT 

FOR VALUE RECEIVED, the undersigned hereby sell(s), assign(s) and transfer(s) unto
                                         
             
  

					
	 PLEASE INSERT SOCIAL SECURITY OR OTHER

IDENTIFYING NUMBER OF ASSIGNEE
  
	 		  	
	                 	 		  	

  
  

 
  

(Please Print or Typewrite Name and Address, Including Postal Zip Code, of Assignee) 

 
  

the within Security and all rights thereunder, and hereby irrevocably constitutes and appoints
                                        
                        
                                         
                                         
                                         
                                         
                                      
             
  

 
 to transfer said Security on the books of the
Company, with full power of substitution in the premises. 
 Dated:
                                         
            
 Signature Guaranteed 

 

							
	  
	 	 	 		  	
 

	 	 	 	 		  	 
	NOTICE: Signature must be guaranteed by a member firm of the New York Stock Exchange or a commercial bank or trust company.	 	 	 		  	NOTICE: The signature to this assignment must correspond with the name as written upon the face of the within Security in every particular,
without alteration or enlargement or any change whatever.


  
 11