As filed with the Securities and Exchange Commission on August 20, 2025 Registration No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 (Primary Standard Industrial Classification Code Number) Delaware 8731 27-0480143 (IRS Employer Identification No.) FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 iSpecimen, Inc. (Exact name of registrant as specified in its charter) (State or jurisdiction of incorporation or organization) 8 Cabot Road, Suite 1800 Woburn, MA 0 ...