Exhibit 4.1


 


SPECIMEN
UNIT CERTIFICATE


 





	SEE REVERSE FOR CERTAIN

DEFINITIONS	MSD Acquisition Corp.	NUMBER UNITS U-
	 	 	CUSIP [  ]




 


UNITS
CONSISTING OF ONE CLASS A ORDINARY SHARE AND ONE-FIFTH OF ONE

REDEEMABLE WARRANT TO PURCHASE ONE CLASS A ORDINARY SHARE


 


THIS
CERTIFIES THAT                 is the owner of                
Units.


 


Each
Unit (“Unit”) consists of one (1) Class A ordinary share, par value $0.0001 per share (“Ordinary Shares”),
of MSD Acquisition Corp., a Cayman Islands exempted company (the “Company”), and one-fifth (1/5) of one redeemable
warrant (each whole warrant, a “Warrant”). Each Warrant entitles the holder to purchase one (1) Ordinary Share for
$11.50 per share (subject to adjustment). Each Warrant will become exercisable on the later of (i) thirty (30) days after the
Company’s completion of a merger, share exchange, asset acquisition, share purchase, reorganization or other similar business
combination with one or more businesses (each, a “Business Combination”), and (ii) twelve (12) months from the closing
of the Company’s initial public offering, and will expire unless exercised before 5:00 p.m., New York City Time, on the
date that is five (5) years after the date on which the Company completes its initial Business Combination, or earlier upon redemption
or liquidation (the “Expiration Date”). The Ordinary Shares and Warrants comprising the Units represented by this
certificate are not transferable separately prior to       , 2021, unless Goldman, Sachs, &
Co. LLC and Morgan Stanley & Co. LLC elect to allow earlier separate trading, subject to the Company’s filing with the
Securities and Exchange Commission of a Current Report on Form 8-K containing an audited balance sheet reflecting the Company’s
receipt of the gross proceeds of the initial public offering and issuing a press release announcing when separate trading will
begin. No fractional warrants will be issued upon separation of the Units and only whole warrants are exercisable. The terms of
the Warrants are governed by a Warrant Agreement, dated as of        , 2021, between the Company
and Continental Stock Transfer & Trust Company, as Warrant Agent, and are subject to the terms and provisions contained therein,
all of which terms and provisions the holder of this certificate consents to by acceptance hereof. Copies of the Warrant Agreement
are on file at the office of the Warrant Agent at 1 State Street, 30th Floor, New York, New York 10004, and are available to any
Warrant holder on written request and without cost.


 


Upon
the consummation of the Business Combination, the Units represented by this certificate will automatically separate into the Class
A Ordinary Shares and Warrants comprising such Units.


 


This
certificate is not valid unless countersigned by the Transfer Agent and Registrar of the Company.


 


This
certificate shall be governed by and construed in accordance with the internal laws of the State of New York.


 


Witness
the facsimile signatures of its duly authorized officers.


 


	By	 	 	 
	 	Chief
    Executive Officer	 	Chief
    Financial Officer


 




     


     


    

 


MSD
Acquisition Corp.


 


The
Company will furnish without charge to each unitholder who so requests, a statement of the powers, designations, preferences and
relative, participating, optional or other special rights of each class of shares or series thereof of the Company and the qualifications,
limitations or restrictions of such preferences and/or rights.


 


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


 





	TEN
    COM	—	as
    tenants in common	 	 	 	 	Custodian	 
	 	 	 	 	 	 	(Cust)	 	(Minor)
	 	 	 	 	 	 	 	 	 
	TEN
    ENT-	—	as
    tenants by the entireties	 	 	 		 	
	 	 	 	 	 	 	 	(State)	 
	JT
    TEN-	—	as
    joint tenants with right of survivorship and not as tenants in common	 	 	
	 	 	 	 	 	 
	UNIF
    GIFT

    MIN ACT	—	under
    Uniform Gifts to Minors Act	 	 	 
	 	 	Additional
    abbreviations may also be used though not in the above list.	 	 	 


 



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For
value received,                 hereby sells, assigns
and transfers unto                


 


PLEASE
INSERT SOCIAL SECURITY OR OTHER IDENTIFYING NUMBER OF ASSIGNEE


 


(PLEASE
PRINT OR TYPEWRITE NAME AND ADDRESS, INCLUDING ZIP CODE, OF ASSIGNEE)


 


Units represented by the within Certificate, and does hereby irrevocably constitute and appoint                 Attorney to transfer the said Units on the books of the within named Company with full power of substitution in the premises.




 


 





	Dated	 	 	 	 
		 	 	Notice:
                                         The signature on this assignment must correspond with the name as written upon the face of the certificate
    in every particular, without alteration or enlargement or any change whatever.


 


Signature(s)
Guaranteed:


 


 


	THE SIGNATURE(S) MUST BE GUARANTEED BY AN ELIGIBLE GUARANTOR INSTITUTION (BANKS, STOCKBROKERS, SAVINGS
    AND LOAN ASSOCIATIONS AND CREDIT UNIONS WITH MEMBERSHIP IN AN APPROVED SIGNATURE GUARANTEE MEDALLION PROGRAM, PURSUANT TO
    S.E.C. RULE 17Ad-15 OR ANY SUCCESSOR RULES).	 









 


In
each case, as more fully described in the Company’s final prospectus dated                ,
2021, the holder(s) of this certificate shall be entitled to receive a pro-rata portion of certain funds held in the trust account
established in connection with the Company’s initial public offering only in the event that (i) the Company redeems the
Ordinary Shares sold in its initial public offering and liquidates because it does not consummate an initial business combination
within the period of time set forth in the Company’s amended and restated memorandum and articles of association, as the
same may be amended from time to time, (ii) the Company redeems the Ordinary Shares sold in its initial public offering in connection
with a shareholder vote to amend the Company’s amended and restated memorandum and articles of association (A) to modify
the substance or timing of the Company’s obligation to provide holders of the Ordinary Shares the right to have their shares
redeemed in connection with the Company’s initial business combination or to redeem 100% of the Ordinary Shares if the Company
does not complete its initial business combination within the time period set forth therein or (B) with respect to any other provision
relating to the rights of holders of the Ordinary Shares or pre-initial business combination activity, or (iii) if the holder(s)
seek(s) to redeem for cash his, her, its or their respective Ordinary Shares in connection with a tender offer (or proxy solicitation,
solely in the event the Company seeks shareholder approval of the proposed initial business combination) setting forth the details
of a proposed initial business combination. In no other circumstances shall the holder(s) have any right or interest of any kind
in or to the trust account.


 



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