EX-4.2



 Exhibit 4.2 
  





 
 ZQ|CERT#|COY|CLS|RGSTRY|ACCT#|TRANSTYPE|RUN#|TRANS#

COMMON STOCK 
PAR VALUE $0.0001 
COMMON STOCK 
Certificate Number 
ZQ00000000 
UNITY BIOTECHNOLOGY, INC. 
INCORPORATED UNDER THE LAWS OF THE STATE OF DELAWARE 
Shares 
* * 000000 ****************** 
* * * 000000 ***************** **** 000000 ****************
***** 000000 *************** ****** 000000 ************** 
THIS CERTIFIES THAT

is the owner of 
SEE REVERSE FOR CERTAIN DEFINITIONS 
CUSIP 91381U 10 1 
THIS CERTIFICATE IS TRANSFERABLE IN CITIES DESIGNATED BY THE TRANSFER

AGENT, AVAILABLE ONLINE AT www.computershare.com 
FULLY-PAID AND
NON-ASSESSABLE SHARES OF COMMON STOCK OF 
Unity Biotechnology, Inc. (hereinafter called the “Company”), transferable on the books of the Company in person
or by duly authorized attorney, upon surrender of this Certificate properly endorsed. This Certificate and the shares represented hereby, are issued and shall be held subject to all of the provisions of the Certificate of Incorporation, as amended,
and the Bylaws, as amended, of the Company (copies of which are on file with the Company and with the Transfer Agent), to all of which each holder, by acceptance hereof, assents. This Certificate is not valid unless countersigned and registered by
the Transfer Agent and Registrar. 
Witness the facsimile seal of the Company and the facsimile signatures of its duly authorized officers. 
DATED DD-MMM-YYYY 
COUNTERSIGNED AND REGISTERED: 
COMPUTERSHARE TRUST COMPANY, N.A. 
TRANSFER AGENT AND REGISTRAR, 
By 
AUTHORIZED SIGNATURE 
President 
Secretary 
CUSIP/IDENTIFIER XXXXXX XX X 
Holder ID XXXXXXXXXX 
Insurance Value 1,000,000.00 Number of Shares 123456 
DTC 12345678 123456789012345 
PO BOX 43004, Providence, RI 02940-3004 
Certificate Numbers Num/No. Denom. Total 
MR A SAMPLE 1234567890/1234567890 1 1 1 DESIGNATION (IF ANY) 1234567890/1234567890 2 2 2 
ADD 1

ADD 2 1234567890/1234567890 3 3 3 1234567890/1234567890 4 4 4 
ADD 3

ADD 4 1234567890/1234567890 5 5 5 1234567890/1234567890 6 6 6 
Total
Transaction 7 







 



 
 UNITY BIOTECHNOLOGY, INC 
THE COMPANY WILL FURNISH
WITHOUT CHARGE TO EACH SHAREHOLDER WHO SO REQUESTS, A SUMMARY OF THE POWERS, DESIGNATIONS, PREFERENCES AND RELATIVE, PARTICIPATING, OPTIONAL OR OTHER SPECIAL RIGHTS OF EACH CLASS OF STOCK OF THE COMPANY AND THE QUALIFICATIONS, LIMITATIONS OR
RESTRICTIONS OF SUCH PREFERENCES AND RIGHTS, AND THE VARIATIONS IN RIGHTS, PREFERENCES AND LIMITATIONS DETERMINED FOR EACH SERIES, WHICH ARE FIXED BY THE CERTIFICATE OF INCORPORATION OF THE COMPANY, AS AMENDED, AND THE RESOLUTIONS OF THE BOARD OF
DIRECTORS OF THE COMPANY, AND THE AUTHORITY OF THE BOARD OF DIRECTORS TO DETERMINE VARIATIONS FOR FUTURE SERIES. SUCH REQUEST MAY BE MADE TO THE OFFICE OF THE SECRETARY OF THE COMPANY OR TO THE TRANSFER AGENT. THE BOARD OF DIRECTORS MAY REQUIRE THE
OWNER OF A LOST OR DESTROYED STOCK CERTIFICATE, OR HIS LEGAL REPRESENTATIVES, TO GIVE THE COMPANY A BOND TO INDEMNIFY IT AND ITS TRANSFER AGENTS AND REGISTRARS AGAINST ANY CLAIM THAT MAY BE MADE AGAINST THEM ON ACCOUNT OF THE ALLEGED LOSS OR
DESTRUCTION OF ANY SUCH CERTIFICATE. 
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 UNIF GIFT MIN ACT —   Custodian 
(Cust) 
(Minor) 
TEN ENT - as tenants by the entireties under Uniform Gifts to Minors Act 
(State) 
JT TEN - as joint tenants with right of survivorship UNIF TRF MIN ACT —   Custodian (until age ) 
and not as tenants in common 
(Cust) 
under Uniform Transfers to Minors Act 
(Minor) 
(State) 
Additional abbreviations may also be used though not in the above list. 
PLEASE INSERT SOCIAL SECURITY OR OTHER IDENTIFYING NUMBER OF ASSIGNEE 
For value received,
____________________________hereby sell, assign and transfer unto 
(PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS, INCLUDING POSTAL ZIP CODE, OF ASSIGNEE) 
_______________________________________________________________________________________________________________________ Shares of the common stock represented by the within
Certificate, and do hereby irrevocably constitute and appoint _______________________________________________________________________________________________________________________ Attorney to transfer the said stock on the books of the
within-named Company with full power of substitution in the premises. 
Dated: __________________________________________20 Signature(s) Guaranteed: Medallion
Guarantee Stamp 
THE SIGNATURE(S) SHOULD 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. 
Signature: 
Signature: 
Notice: The signature to 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. 
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