EXHIBIT 4.2







NEITHER THIS SECURITY NOR THE SECURITIES
FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION
OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES
ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD OR OTHERWISE TRANSFERRED, PLEDGED OR HYPOTHECATED EXCEPT PURSUANT TO
AN EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT OR PURSUANT TO AN AVAILABLE EXEMPTION FROM, OR IN A TRANSACTION NOT
SUBJECT TO, THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT AND IN ACCORDANCE WITH APPLICABLE STATE SECURITIES LAWS AS EVIDENCED
BY A LEGAL OPINION OF COUNSEL TO THE TRANSFEROR TO SUCH EFFECT, THE SUBSTANCE OF WHICH SHALL BE REASONABLY ACCEPTABLE TO THE COMPANY.





COMMON STOCK PURCHASE WARRANT



SPECTRASCIENCE,
Inc.





Warrant Shares: [_______]	Initial Exercise Date: __________,
2012





THIS COMMON STOCK PURCHASE
WARRANT (the “Warrant”) certifies that, for value received, _____________ (the “Holder”)
is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on
or after the date hereof (the “Initial Exercise Date”) and on or prior to the close of business on the five
year anniversary of the Initial Exercise Date (the “Termination Date”) but not thereafter, to subscribe for
and purchase from SpectraScience, Inc., a Minnesota corporation (the “Company”), up to ______ shares (the “Warrant
Shares”) of Common Stock. The purchase price of one share of Common Stock under this Warrant shall be equal to the Exercise
Price, as defined in Section 2(b).



Section 1.	Definitions.
For the purposes hereof, in addition to the terms defined elsewhere in this Warrant, (a) capitalized terms not otherwise defined
herein shall have the meanings set forth in the Purchase Agreement and (b) the following terms shall have the following meanings:



“Business
Day” means any day except any Saturday, any Sunday, any day which shall be a federal legal holiday in the United States
or any day on which banking institutions in the State of New York are authorized or required by law or other governmental action
to close.





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“Common
Stock Equivalents” means any securities of the Company or the Subsidiaries which would entitle the holder thereof to
acquire at any time Common Stock, including, without limitation, any debt, preferred stock, rights, options, warrants or other
instrument that is at any time convertible into or exercisable or exchangeable for, or otherwise entitles the holder thereof to
receive Common Stock.



“Person”
means an individual or corporation, partnership, trust, incorporated or unincorporated association, joint venture, limited liability
company, joint stock company, government (or an agency or subdivision thereof) or other entity of any kind.



“Purchase
Agreement” means the Subscription Agreement, dated as of ___________, 2012 among the Company and the original Holders,
as amended, modified or supplemented from time to time in accordance with its terms.



“Securities
Act” means the Securities Act of 1933, as amended, and the rules and regulations promulgated thereunder.



“Subsidiary”
shall have the meaning set forth in the Purchase Agreement.



“Trading
Day” means a day on which the New York Stock Exchange is open for business.



“Trading
Market” means the following markets or exchanges on which the Common Stock is listed or quoted for trading on the date
in question: the NYSE AMEX LLC, the Nasdaq Capital Market, the Nasdaq Global Market, the Nasdaq Global Select Market, the New York
Stock Exchange or the OTC Bulletin Board, or the other OTC markets, including the OTCQX, OTCQB and OTC Pink markets.



“Transaction
Documents” shall have the meaning set forth in the Purchase Agreement.



“VWAP”
means, for any date, the price determined by the first of the following clauses that applies: (a) if the Common Stock is then listed
or quoted on a national securities exchange, the daily volume weighted average price of the Common Stock for such date (or the
nearest preceding date) on the trading market on which the Common Stock is then listed or quoted as reported by Bloomberg L.P.
(based on a Trading Day from 9:30 a.m. New York City time to 4:02 p.m. New York City time); (b)  if the Common Stock is quoted
on the OTC Bulletin Board, the volume weighted average price of the Common Stock for such date (or the nearest preceding date)
on the OTC Bulletin Board; (c) if the Common Stock is not then listed or quoted for trading on the OTC Bulletin Board and if prices
for the Common Stock are then reported on the OTC markets, including the OTCQX, OTCQB and OTC Pink markets, or in the “Pink
Sheets” published by Pink Sheets, LLC (or a similar organization or agency succeeding to its functions of reporting prices),
the most recent bid price per share of the Common Stock so reported; or (d) in all other cases, the fair market value of a
share of Common Stock as determined by an independent appraiser selected in good faith by the Subscribers of a majority in interest
of the Securities then outstanding and reasonably acceptable to the Company, the fees and expenses of which shall be paid by the
Company; provided that in each case where Bloomberg L.P. data is being relied upon, Holder shall provide to the Company a copy
of such information for the Company's records.





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Section 2.	Exercise.



a)	Exercise
of Warrant. Exercise of the purchase rights represented by this Warrant may be made, in whole or in part, at any time or times
on or after the Initial Exercise Date and on or before the Termination Date by delivery to the Company (or such other office or
agency of the Company as it may designate by notice in writing to the registered Holder at the address of the Holder appearing
on the books of the Company) of a duly executed facsimile copy of the notice of exercise (“Notice of Exercise”) form
annexed hereto; and, within 3 Trading Days of the date said Notice of Exercise is delivered to the Company, the Company shall have
received payment of the aggregate Exercise Price of the shares thereby purchased by wire transfer or cashier’s check drawn
on a United States bank. Notwithstanding anything herein to the contrary, the Holder shall not be required to physically surrender
this Warrant to the Company until the Holder has purchased all of the Warrant Shares available hereunder and the Warrant has been
exercised in full, in which case, the Holder shall surrender this Warrant to the Company for cancellation within 3 Trading Days
of the date the final Notice of Exercise is delivered to the Company. Partial exercises of this Warrant resulting in purchases
of a portion of the total number of Warrant Shares available hereunder shall have the effect of lowering the outstanding number
of Warrant Shares purchasable hereunder in an amount equal to the applicable number of Warrant Shares purchased. The Holder and
the Company shall maintain records showing the number of Warrant Shares purchased and the date of such purchases. In the event
of any dispute or discrepancy, the records of the Company shall be controlling and determinative in the absence of manifest error.



b)	Exercise
Price. The exercise price per share of the Common Stock under this Warrant shall be $0.1287, subject to adjustment hereunder
(the “Exercise Price”).



c)	Cashless
Exercise. This Warrant may also be exercised at any time after the Initial Exercise Date at such time by means of a “cashless
exercise” in which the Holder shall be entitled to receive a certificate for the number of Warrant Shares equal to the quotient
obtained by dividing [(A-B) (X)] by (A), where:



| | (A) | = the VWAP on the ten (10) Trading Days immediately preceding
the date of such election;
| | --- | ----------------------------------------------------------------------------------------



| | (B) | = the Exercise Price of this Warrant, as adjusted; and
| | --- | ------------------------------------------------------



| | (X) | = the number of Warrant Shares issuable upon exercise
of this Warrant in accordance with the terms of this Warrant, or if only a portion of the Warrant is being exercised, the portion
of the Warrant being exercised, by means of a cash exercise rather than a cashless exercise.
| | --- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------





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Notwithstanding
anything herein to the contrary, on the Termination Date, this Warrant shall be automatically exercised via cashless exercise pursuant
to this Section 2(c).



d)	Exercise
Limitations. Holder shall not have the right to exercise any portion of this Warrant, pursuant to Section 2 or otherwise, to
the extent that after giving effect to such issuance after exercise, the Holder (together with the Holder’s affiliates, and
any other person or entity acting as a group together with the Holder or any of the Holder’s affiliates), would beneficially
own in excess of the Beneficial Ownership Limitation (as defined below). For purposes of this Section, beneficial ownership shall
be calculated in accordance with Section 13(d) of the Exchange Act and the rules and regulations promulgated thereunder. Holder
is solely responsible for any schedules required to be filed in accordance therewith. The Company shall have no obligation to verify
or confirm the accuracy of such filings.  In any case, the number of outstanding shares of Common Stock shall be determined
after giving effect to the conversion or exercise of securities of the Company, including this Warrant, by the Holder or its affiliates
since the date as of which such number of outstanding shares of Common Stock was reported. The “Beneficial Ownership Limitation”
shall be 4.99% of the number of shares of the Common Stock outstanding immediately after giving effect to the issuance of Warrant
Shares issuable upon exercise of this Warrant. The Holder, upon not less than 61 days’ prior notice to the Company, may increase
or decrease the Beneficial Ownership Limitation provisions of this Section 2(d), provided that the Beneficial Ownership Limitation
in no event exceeds 9.99% of the number of shares of the Common Stock outstanding immediately after giving effect to the issuance
of Warrant Shares upon exercise of this Warrant held by the Holder and the provisions of this Section 2(d) shall continue to apply.
Any such increase or decrease will not be effective until the 61st day after such notice is delivered to the Company.
The limitations contained in this paragraph shall apply to a successor holder of this Warrant.



e)	Mechanics
of Exercise.



i.	Delivery
of Certificates Upon Exercise. Certificates for shares purchased hereunder shall be transmitted by the Company’s transfer
agent (the “Transfer Agent”) to the Holder by crediting the account of the Holder’s prime broker with
the Depository Trust Company through its Deposit Withdrawal Agent Commission (“DWAC”) system if the Company
is then a participant in such system and either (A) there is an effective registration statement permitting the resale of the Warrant
Shares by the Holder or (B) the shares are eligible for resale without volume or manner-of-sale limitations pursuant to Rule 144,
and otherwise by physical delivery of certificates to the address specified by the Holder in the Notice of Exercise within 4 Trading
Days from the delivery to the Company of the Notice of Exercise Form, surrender of this Warrant (if required) and payment of the
aggregate Exercise Price as set forth above (the “Warrant Share Delivery Date”). This Warrant shall be deemed
to have been exercised on the date the Exercise Price is received by the Company. The Warrant Shares shall be deemed to have been
issued, and Holder or any other person so designated to be named therein shall be deemed to have become a holder of record of such
shares for all purposes, as of the date the Warrant has been exercised by payment to the Company of the Exercise Price and all
taxes required to be paid by the Holder, if any, pursuant to Section 2(e)(vi) prior to the issuance of such shares, have been paid.
If the Company is obligated to and fails for any reason to deliver to the Holder certificates evidencing the Warrant Shares subject
to a Notice of Exercise by the Warrant Share Delivery Date, the Company shall pay to the Holder, in cash, as liquidated damages
and not as a penalty, for each $1,000 of Warrant Shares subject to such exercise, $10 per Trading Day (increasing to $20 per Trading
Day on the seventh Trading Day after such liquidated damages begin to accrue) for each Trading Day after such Warrant Share Delivery
Date until such certificates are delivered.





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ii.	Delivery
of New Warrants Upon Exercise. If this Warrant shall have been exercised in part, the Company shall, at the request of a Holder
and upon surrender of this Warrant certificate, at the time of delivery of the certificate or certificates representing Warrant
Shares, deliver to Holder a new Warrant evidencing the rights of Holder to purchase the unpurchased Warrant Shares called for by
this Warrant, which new Warrant shall in all other respects be identical with this Warrant.



iii.	Compensation
for Buy-In on Failure to Timely Deliver Certificates Upon Exercise. In addition to any other rights available to the Holder,
if the Company fails for any reason to deliver to the Holder such certificate or certificates by the Warrant Share Delivery Date,
and if after such Warrant Share Delivery Date the Holder is required by its brokerage firm to purchase (in an open market transaction
or otherwise), or the Holder’s brokerage firm otherwise purchases, shares of Common Stock to deliver in satisfaction of a
sale by the Holder of the Warrant Shares which the Holder was entitled to receive upon the conversion relating to such Warrant
Share Delivery Date (a “Buy-In”), then the Company shall (A) pay in cash to the Holder (in addition to any other
remedies available to or elected by the Holder) the amount by which (x) the Holder’s total purchase price (including any
brokerage commissions) for the Common Stock so purchased exceeds (y) the product of (1) the aggregate number of Warrant Shares
that the Holder was entitled to receive from the conversion at issue multiplied by (2) the actual sale price at which the sell
order giving rise to such purchase obligation was executed (including any brokerage commissions) and (B) at the option of the Holder,
either reissue (if surrendered) this Warrant in a principal amount equal to the principal amount of the attempted conversion or
deliver to the Holder the number of shares of Common Stock that would have been issued if the Company had timely complied with
its delivery requirements under this Warrant. For example, if the Holder purchases Common Stock having a total purchase price of
$11,000 to cover a Buy-In with respect to an attempted exercise of this Warrant with respect to which the actual sale price of
the Warrant Shares (including any brokerage commissions) giving rise to such purchase obligation was a total of $10,000 under clause
(A) of the immediately preceding sentence, the Company shall be required to pay the Holder $1,000. The Holder shall provide the
Company written notice indicating the amounts payable to the Holder in respect of the Buy-In and, upon request of the Company,
evidence of the amount of such loss. Nothing herein shall limit a Holder’s right to pursue any other remedies available to
it hereunder, at law or in equity including, without limitation, a decree of specific performance and/or injunctive relief with
respect to the Company’s failure to timely deliver certificates representing Warrant Shares upon exercise of this Warrant
as required pursuant to the terms hereof.





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iv.	No
Fractional Shares or Scrip. No fractional shares or scrip representing fractional shares shall be issued upon the exercise
of this Warrant. As to any fraction of a share which Holder would otherwise be entitled to purchase upon such exercise, the Company
shall, at its election, either pay a cash adjustment in respect of such final fraction in an amount equal to such fraction multiplied
by the Exercise Price or round up to the next whole share.



v.	Charges,
Taxes and Expenses. Issuance of certificates for Warrant Shares shall be made without charge to the Holder for any issue or
transfer tax or other incidental expense in respect of the issuance of such certificate, all of which taxes and expenses shall
be paid by the Company, and such certificates shall be issued in the name of the Holder or in such name or names as may be directed
by the Holder; provided, however, that in the event certificates for Warrant Shares are to be issued in a name other
than the name of the Holder, this Warrant when surrendered for exercise shall be accompanied by the assignment form (“Assignment
Form”) attached hereto duly executed by the Holder and the Company may require, as a condition thereto, the payment of a
sum sufficient to reimburse it for any transfer tax incidental thereto.



vi.	Closing
of Books. The Company will not close its shareholder books or records in any manner which prevents the timely exercise of this
Warrant, pursuant to the terms hereof.



Section 3.	Certain
Adjustments.





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a)	Stock
Dividends and Splits. If the Company, at any time while this Warrant is outstanding: (i) pays a stock dividend or otherwise
make a distribution or distributions on shares of its Common Stock or any other equity or equity equivalent securities payable
in shares of Common Stock (which, for avoidance of doubt, shall not include any Warrant Shares issued by the Company upon exercise
of this Warrant), (ii) subdivides outstanding shares of Common Stock into a larger number of shares, (iii) combines (including
by way of reverse stock split) outstanding shares of Common Stock into a smaller number of shares or (iv) issues by reclassification
of shares of the Common Stock any shares of capital stock of the Company, then in each case the Exercise Price shall be multiplied
by a fraction of which the numerator shall be the number of shares of Common Stock (excluding treasury shares, if any) outstanding
immediately before such event and of which the denominator shall be the number of shares of Common Stock outstanding immediately
after such event and the number of shares issuable upon exercise of this Warrant shall be proportionately adjusted such that the
aggregate Exercise Price of this Warrant shall remain unchanged. Any adjustment made pursuant to this Section 3(a) shall become
effective immediately after the record date for the determination of shareholders entitled to receive such dividend or distribution
and shall become effective immediately after the effective date in the case of a subdivision, combination or re-classification.



b)	Fundamental
Transaction. If, at any time while this Warrant is outstanding, (i) the Company effects any merger or consolidation of the
Company with or into another Person, (ii) the Company effects any sale of all or substantially all of its assets in one or a series
of related transactions, (iii) any tender offer or exchange offer (whether by the Company or another Person) is completed pursuant
to which holders of Common Stock are permitted to tender or exchange their shares for other securities, cash or property or (iv)
the Company effects any reclassification of the Common Stock or any compulsory share exchange pursuant to which the Common Stock
is effectively converted into or exchanged for other securities, cash or property (each “Fundamental Transaction”),
then, upon any subsequent exercise of this Warrant, the Holder shall have the right to receive, for each Warrant Share that would
have been issuable upon such exercise immediately prior to the occurrence of such Fundamental Transaction, the number of shares
of Common Stock of the successor or acquiring corporation or of the Company, if it is the surviving corporation, and any additional
consideration (the “Alternate Consideration”) receivable as a result of such merger, consolidation or disposition
of assets by a holder of the number of shares of Common Stock for which this Warrant is exercisable immediately prior to such event.
For purposes of any such exercise, the determination of the Exercise Price shall be appropriately adjusted to apply to such Alternate
Consideration based on the amount of Alternate Consideration issuable in respect of one share of Common Stock in such Fundamental
Transaction, and the Company shall apportion the Exercise Price among the Alternate Consideration in a reasonable manner reflecting
the relative value of any different components of the Alternate Consideration. If holders of Common Stock are given any choice
as to the securities, cash or property to be received in a Fundamental Transaction, then the Holder shall be given the same choice
as to the Alternate Consideration it receives upon any exercise of this Warrant following such Fundamental Transaction. To the
extent necessary to effectuate the foregoing provisions, any successor to the Company or surviving entity in such Fundamental Transaction
shall issue to the Holder a new warrant consistent with the foregoing provisions and evidencing the Holder’s right to exercise
such warrant into Alternate Consideration. The terms of any agreement pursuant to which a Fundamental Transaction is effected shall
include terms requiring any such successor or surviving entity to comply with the provisions of this Section 3(b) and insuring
that this Warrant (or any such replacement security) will be similarly adjusted upon any subsequent transaction analogous to a
Fundamental Transaction. Notwithstanding anything to the contrary, in the event of a Fundamental Transaction that is (1) an all
cash transaction, (2) a “Rule 13e-3 transaction” as defined in Rule 13e-3 under the Exchange Act, or (3) a Fundamental
Transaction involving a person or entity not traded on a national securities exchange, the Nasdaq Global Select Market, the Nasdaq
Global Market, or the Nasdaq Capital Market, the Company or any successor entity shall pay at the Holder’s option, exercisable
at any time concurrently with or within 30 days after the consummation of the Fundamental Transaction, an amount of cash equal
to the value of this Warrant as determined in accordance with the Black Scholes Option Pricing Model obtained from the “OV”
function on Bloomberg L.P. using (A) a price per share of Common Stock equal to the VWAP of the Common Stock for the Trading Day
immediately preceding the date of consummation of the applicable Fundamental Transaction, (B) a risk-free interest rate corresponding
to the U.S. Treasury rate for a 30 day period immediately prior to the consummation of the applicable Fundamental Transaction,
(C) an expected volatility equal to the 100 day volatility obtained from the “HVT” function on Bloomberg L.P. determined
as of the Trading Day immediately following the public announcement of the applicable Fundamental Transaction and (D) a remaining
option time equal to the time between the date of the public announcement of such transaction and the Termination Date; provided
that in each case where Bloomberg L.P. data is being relied upon, Holder shall provide to the Company a copy of such information
for the Company's records.





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c)	Calculations.
All calculations under this Section 3 shall be made to the nearest cent or the nearest 1/100th of a share, as the case may be.
For purposes of this Section 3, the number of shares of Common Stock deemed to be issued and outstanding as of a given date shall
be the sum of the number of shares of Common Stock (excluding treasury shares, if any) issued and outstanding.



d)	Notice
to Holder.



i.	Adjustment
to Exercise Price. Whenever the Exercise Price is adjusted pursuant to any provision of this Section 3, the Company shall promptly
mail to the Holder a notice setting forth the Exercise Price after such adjustment and setting forth a brief statement of the facts
requiring such adjustment.



ii.	Notice
to Allow Exercise by Holder. If (A) the Company shall declare a dividend (or any other distribution in whatever form) on the
Common Stock, (B) the Company shall declare a special nonrecurring cash dividend on or a redemption of the Common Stock, (C) the
Company shall authorize the granting to all holders of the Common Stock rights or warrants to subscribe for or purchase any shares
of capital stock of any class or of any rights, (D) the approval of any shareholders of the Company shall be required in connection
with any reclassification of the Common Stock, any consolidation or merger to which the Company is a party, any sale or transfer
of all or substantially all of the assets of the Company, of any compulsory share exchange whereby the Common Stock is converted
into other securities, cash or property, or (E) the Company shall authorize the voluntary or involuntary dissolution, liquidation
or winding up of the affairs of the Company, then, in each case, the Company shall cause to be mailed to the Holder at its last
address as it shall appear upon the Warrant Register of the Company, at least 20 calendar days prior to the applicable record or
effective date hereinafter specified, a notice stating (x) the date on which a record is to be taken for the purpose of such dividend,
distribution, redemption, rights or warrants, or if a record is not to be taken, the date as of which the holders of the Common
Stock of record to be entitled to such dividend, distributions, redemption, rights or warrants are to be determined or (y) the
date on which such reclassification, consolidation, merger, sale, transfer or share exchange is expected to become effective or
close, and the date as of which it is expected that holders of the Common Stock of record shall be entitled to exchange their shares
of the Common Stock for securities, cash or other property deliverable upon such reclassification, consolidation, merger, sale,
transfer or share exchange; provided that the failure to mail such notice or any defect therein or in the mailing thereof shall
not affect the validity of the corporate action required to be specified in such notice. The Holder is entitled to exercise this
Warrant during the period commencing on the date of such notice to the effective date of the event triggering such notice.



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Section 4.	Transfer
of Warrant.



a)	Transferability.
Subject to compliance with any applicable securities laws and the conditions set forth in Section 4(d) herein and to the provisions
of the Purchase Agreement, this Warrant and all rights hereunder (including, without limitation, any registration rights) are transferable,
in whole or in part, upon surrender of this Warrant at the principal office of the Company or its designated agent, together with
a written assignment of this Warrant substantially in the form attached hereto duly executed by the Holder or its agent or attorney
and funds sufficient to pay any transfer taxes payable upon the making of such transfer. Upon such surrender and, if required,
such payment, the Company shall execute and deliver a new Warrant or Warrants in the name of the assignee or assignees, as applicable,
and in the denomination or denominations specified in such instrument of assignment, and shall issue to the assignor a new Warrant
evidencing the portion of this Warrant not so assigned, and this Warrant shall promptly be cancelled. The Warrant, if properly
assigned, may be exercised by a new holder for the purchase of Warrant Shares without having a new Warrant issued.





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b)	New
Warrants. This Warrant may be divided or combined with other Warrants upon presentation hereof at the aforesaid office of the
Company, together with a written notice specifying the names and denominations in which new Warrants are to be issued, signed by
the Holder or its agent or attorney. Subject to compliance with Section 4(a), as to any transfer which may be involved in such
division or combination, the Company shall execute and deliver a new Warrant or Warrants in exchange for the Warrant or Warrants
to be divided or combined in accordance with such notice. All Warrants issued on transfers or exchanges shall be dated the Initial
Exercise Date and shall be identical with this Warrant except as to the number of Warrant Shares issuable pursuant thereto.



c)	Warrant
Register. The Company shall register this Warrant, upon records to be maintained by the Company for that purpose (the “Warrant
Register”), in the name of the record Holder hereof from time to time. The Company may deem and treat the registered
Holder of this Warrant as the absolute owner hereof for the purpose of any exercise hereof or any distribution to the Holder, and
for all other purposes, absent actual notice to the contrary.



d)	Transfer
Restrictions. If, at the time of the surrender of this Warrant in connection with any transfer of
this Warrant, the transfer of this Warrant shall not be either (i) registered pursuant to an effective registration statement under
the Securities Act and under applicable state securities or blue sky laws or (ii) eligible for resale without volume or manner-of-sale
restrictions pursuant to Rule 144, the Company may require, as a condition of allowing such transfer, that the Holder or transferee
of this Warrant, as the case may be, comply with the provisions of the Purchase Agreement.



Section 5.	Miscellaneous.



a)	No
Rights as Shareholder Until Exercise. This Warrant does not entitle the Holder to any voting rights or other rights as a shareholder
of the Company prior to the exercise hereof.



b)	Loss,
Theft, Destruction or Mutilation of Warrant. The Company covenants that upon receipt by the Company of evidence reasonably
satisfactory to it of the loss, theft, destruction or mutilation of this Warrant or any stock certificate relating to the Warrant
Shares, and in case of loss, theft or destruction, of indemnity or security reasonably satisfactory to it (which, in the case of
the Warrant, shall not include the posting of any bond), and upon surrender and cancellation of such Warrant or stock certificate,
if mutilated, the Company will make and deliver a new Warrant or stock certificate of like tenor and dated as of such cancellation,
in lieu of such Warrant or stock certificate.





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c)	Saturdays,
Sundays, Holidays, etc. If the last or appointed day for the taking of any action or the expiration of any right required or
granted herein shall not be a Business Day, then, such action may be taken or such right may be exercised on the next succeeding
Business Day.



d)	Authorized
Shares.



The Company
covenants that, during the period the Warrant is outstanding, it will reserve from its authorized and unissued Common Stock one
hundred (100%) of the number of shares to provide for the issuance of the Warrant Shares upon the exercise of any purchase rights
under this Warrant. In case such amount of Common Stock is insufficient at any time, the Company shall call and hold a special
meeting to increase the number of authorized shares of common stock. Management of the Company shall recommend to shareholders
to vote in favor of increasing the number of authorized shares of common stock.



The Company
further covenants that its issuance of this Warrant shall constitute full authority to its officers who are charged with the duty
of executing stock certificates to execute and issue the necessary certificates for the Warrant Shares upon the exercise of the
purchase rights under this Warrant. The Company will take all such reasonable action as may be necessary to assure that such Warrant
Shares may be issued as provided herein without violation of any applicable law or regulation, or of any requirements of the Trading
Market upon which the Common Stock may be listed. The Company covenants that all Warrant Shares which may be issued upon the exercise
of the purchase rights represented by this Warrant will, upon exercise of the purchase rights represented by this Warrant, be duly
authorized, validly issued, fully paid and nonassessable and free from all taxes, liens and charges created by the Company in respect
of the issue thereof (other than taxes in respect of any transfer occurring contemporaneously with such issue).



Except and
to the extent as waived or consented to by the Holder, the Company shall not by any action, including, without limitation, amending
its amended and restated articles of incorporation, as amended or through any reorganization, transfer of assets, consolidation,
merger, dissolution, issue or sale of securities or any other voluntary action, avoid or seek to avoid the observance or performance
of any of the terms of this Warrant, but will at all times in good faith assist in the carrying out of all such terms and in the
taking of all such actions as may be necessary or appropriate to protect the rights of Holder as set forth in this Warrant against
impairment. Without limiting the generality of the foregoing, the Company will (i) not increase the par value of any Warrant Shares
above the amount payable therefor upon such exercise immediately prior to such increase in par value, (ii) take all such action
as may be necessary or appropriate in order that the Company may validly and legally issue fully paid and nonassessable Warrant
Shares upon the exercise of this Warrant and (iii) use commercially reasonable efforts to obtain all such authorizations, exemptions
or consents from any public regulatory body having jurisdiction thereof, as may be, necessary to enable the Company to perform
its obligations under this Warrant.





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Before taking
any action which would result in an adjustment in the number of Warrant Shares for which this Warrant is exercisable or in the
Exercise Price, the Company shall obtain all such authorizations or exemptions thereof, or consents thereto, as may be necessary
from any public regulatory body or bodies having jurisdiction thereof.



e)	Jurisdiction.
All questions concerning the construction, validity, enforcement and interpretation of this Warrant shall be determined in accordance
with the provisions of the Purchase Agreement.



f)	Restrictions.
The Holder acknowledges that the Warrant Shares acquired upon the exercise of this Warrant, if not registered, will have restrictions
upon resale imposed by state and federal securities laws.



g)	Nonwaiver
and Expenses. No course of dealing or any delay or failure to exercise any right hereunder on the part of Holder shall operate
as a waiver of such right or otherwise prejudice Holder’s rights, powers or remedies, notwithstanding the fact that all rights
hereunder terminate on the Termination Date. If the Company willfully and knowingly fails to comply with any provision of this
Warrant, which results in any material damages to the Holder, the Company shall pay to Holder such amounts as shall be sufficient
to cover any costs and expenses including, but not limited to, reasonable attorneys’ fees, including those of appellate proceedings,
incurred by Holder in collecting any amounts due pursuant hereto or in otherwise enforcing any of its rights, powers or remedies
hereunder.



h)	Notices.
Any notice, request or other document required or permitted to be given or delivered to the Holder by the Company shall be delivered
in accordance with the notice provisions of the Purchase Agreement.



i)	Limitation
of Liability. No provision hereof, in the absence of any affirmative action by Holder to exercise this Warrant to purchase
Warrant Shares, and no enumeration herein of the rights or privileges of Holder, shall give rise to any liability of Holder for
the purchase price of any Common Stock or as a shareholder of the Company, whether such liability is asserted by the Company or
by creditors of the Company.



j)	Remedies.
The Holder, in addition to being entitled to exercise all rights granted by law, including recovery of damages, will be entitled
to specific performance of its rights under this Warrant. The Company agrees that monetary damages would not be adequate compensation
for any loss incurred by reason of a breach by it of the provisions of this Warrant and hereby agrees to waive and not to assert
the defense in any action for specific performance that a remedy at law would be adequate.



k)	Successors
and Assigns. Subject to applicable securities laws, this Warrant and the rights and obligations evidenced hereby shall inure
to the benefit of and be binding upon the successors of the Company and the successors and permitted assigns of Holder. The provisions
of this Warrant are intended to be for the benefit of all Holders from time to time of this Warrant and shall be enforceable by
the Holder or holder of Warrant Shares.





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l)	Amendment.
This Warrant may be modified or amended or the provisions hereof waived with the written consent of the Company and Holders holding
Warrants at least equal to a majority of the Warrant Shares issuable upon exercise of all then outstanding Warrants.



m)	Severability.
Wherever possible, each provision of this Warrant shall be interpreted in such manner as to be effective and valid under applicable
law, but if any provision of this Warrant shall be prohibited by or invalid under applicable law, such provision shall be ineffective
to the extent of such prohibition or invalidity, without invalidating the remainder of such provisions or the remaining provisions
of this Warrant.



n)	Headings.
The headings used in this Warrant are for the convenience of reference only and shall not, for any purpose, be deemed a part of
this Warrant.



o)	Subscription
Agreement. In connection with the issuance of this Warrant, the Holder has executed a Subscription Agreement (the “Subscription
Agreement”) and hereby acknowledges and agrees that the representations and warranties made by the Holder in such Subscription
Agreement shall be incorporated by reference into this Warrant as if fully set forth herein.







********************



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IN WITNESS WHEREOF, the
Company has caused this Warrant to be executed by its officer thereunto duly authorized as of the date first above indicated.







| | SPECTRASCIENCE, Inc.                                                      
| | --------------------------------------------------------------------------
| | By:__________________________________________
        Name:
        Title:





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NOTICE OF EXERCISE



To:	Spectrascience,
Inc.



(1)	The undersigned
hereby elects to purchase ________ Warrant Shares of the Company pursuant to the terms of the attached Warrant, and tenders herewith
payment of the exercise price in full, together with all applicable transfer taxes, if any.



(2)	Payment shall
take the form of (check applicable box):



[ ] in lawful
money of the United States; or



[ ] the cancellation
of such number of Warrant Shares as is necessary, in accordance with the formula set forth in subsection 2(c), to exercise this
Warrant with respect to the maximum number of Warrant Shares purchasable pursuant to the cashless exercise procedure set forth
in subsection 2(c).



(3)	Please issue a
certificate or certificates representing said Warrant Shares in the name of the undersigned or in such other name as is specified
below:



_______________________________





The Warrant Shares shall be delivered to
the following DWAC Account Number or by physical delivery of a certificate to:



_______________________________



_______________________________



_______________________________



(4) Accredited Investor.
The undersigned is an “accredited investor” as defined in Regulation D promulgated under the Securities Act of 1933,
as amended.



[SIGNATURE
OF HOLDER]





|Name of Investing Entity: |  | 
|------------------------- |  | 



|Signature of Authorized Signatory of Investing Entity: |  | 
|------------------------------------------------------ |  | 



|Name of Authorized Signatory: |  | 
|----------------------------- |  | 



|Title of Authorized Signatory: |  | 
|------------------------------ |  | 



|Date: |  | 
|----- |  | 







15











ASSIGNMENT FORM



(To assign the foregoing warrant, execute
this form and supply required information.
Do not use this form to exercise the warrant.)







FOR VALUE RECEIVED, [____]
all of or [_______] shares of the foregoing Warrant and all rights evidenced thereby are hereby assigned to





_______________________________________________
whose address is



_______________________________________________________________.







_______________________________________________________________



Dated: ______________,
_______







| | Holder’s Signature: | _____________________________
| | ------------------- | -----------------------------
| |                     |                              
| | Holder’s Address:   | _____________________________
| |                     |                              
| |                     | _____________________________







Signature Guaranteed: ___________________________________________





NOTE: The signature to this Assignment
Form must correspond with the name as it appears on the face of the Warrant, without alteration or enlargement or any change whatsoever,
and must be guaranteed by a bank or trust company. Officers of corporations and those acting in a fiduciary or other representative
capacity should file proper evidence of authority to assign the foregoing Warrant.





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