Exhibit 4.1


 





ADD ADD ADD ADD MR PO A 4 3 2 1 DESIGNATIONSAMPLE BOX (IF 505006, ZQ|CERT#|COY|CLS|RGSTRY|ACCT#|TRANSTYPE|RUN#|TRANS# COMMON STOCK PAR
VALUE $0.0001 Certificate Number COMMON STOCK Shares * * 0 0 0 0 0 0 * * * * * * * * * * * * * * * * * * ANY) Louisville, KY 40233 - 5006
ZQ00000000 THIS CERTIFIES THAT PAXMEDICA, INC. INCORPORATED UNDER THE LAWS OF THE STATE OF DELAWARE Mr. Alexander David Sample **** Mr.
Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample Mr. Alexander David
Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample
**** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr.
Alexander David Sample **** MrMR.Alexander.DavidSAMPLEample****Mr.AlexanderDavid&SampleMRS****Mr.Alexander.SAMPLEDavidSample****Mr.Alexander&David
Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr Alexander David Sample
**** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr.
Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David MRSample****.Mr. SAMPLEAlexanderDavidSample****Mr. &AlexanderMRSDavidSample.****
SAMPLEMr.AlexanderDavidSample**** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. lexander David Sample **** Mr. Alexander
David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David
Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample
**** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr.
Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Sample **** Mr. Sample * * * 0 0 0 0 0
0 * * * * * * * * * * * * * * * * * * * * * 0 0 0 0 0 0 * * * * * * * * * * * * * * * * * * * * * 0 0 0 0 0 0 * * * * * * * * * * * *
* * * * * * * * * 0 0 0 0 0 0 * * * * * * * * * * * * * * SEE REVERSE FOR CERTAIN DEFINITIONS CUSIP 70424C 10 4 Total 1234567890/1234567890
1234567890/1234567890 1234567890/1234567890 1234567890/1234567890 1234567890/1234567890 1234567890/1234567890 Certificate DTC Number Insurance
Holder CUSIP/IDENTIFIER Transaction of ID Numbers 12345678 Shares Value 6 5 4 3 2 1 Num/No . 123456789012345 654321 Denom 1,000,000 XXXXXX
.. . XX 7 6 5 4 3 2 1 Total 123456 00 XXXXXXXXXXX is the owner of **000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares***
*000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****
000000**Shares 000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****0
THIS CERTIFICATE IS TRANSFERABLE IN 00000**Shares 000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**
hares****000000**Shares****00 0000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000***ZERO HUNDREDTHOUSAND
CITIES DESIGNATED BY THE TRANSFER 000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****0000
AGENT, AVAILABLE ONLINE AT 00**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000
Shares****00000 0**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000
Shares****000000 **Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000*ZEROHUNDREDANDZERO***
www.computershare.com *Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**
Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**S
FULLY-PAID AND NON-ASSESSABLE SHARES OF COMMON STOCK OF PaxMedica, 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 By-Laws, 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
FACSIMILE SIGNATURE TO COME DIC A E COUNTERSIGNED AND REGISTERED: M ,I X RPORA N P A TE C COMPUTERSHARE TRUST COMPANY, N.A. O . C TRANSFER AGENT
AND REGISTRAR, President 4/15/2020 FACSIMILE SIGNATURE TO COME D E L E R AWA Secretary By AUTHORIZED SIGNATURE






     


     


    

 








PAXMEDICA,
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: 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. 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. The IRS requires that the named transfer agent (“we”) report the cost basis
of certain shares or units acquired after January 1, 2011. If your shares or units are covered by the legislation, and
you requested to sell or transfer the shares or units using a specific cost basis calculation method, then we have processed as
you requested. If you did not specify a cost basis calculation method, then we have defaulted to the first in, first out (FIFO)
method. Please consult your tax advisor if you need additional information about cost basis. If you do not keep in contact with
the issuer or do not have any activity in your account for the time period specified by state law, your property may become subject
to state unclaimed property laws and transferred to the appropriate state.