FDA Revises Draft Guidance for 17 Generic Peptide Products Including Semaglutide and Tirzepatide; Public Comment Period Runs Through September 28, 2026
The U.S. FDA published updated draft guidance for 17 generic peptide products in early September 2026, with the public comment period running through September 28, 2026. The guidance covers testing standards, comparative analytical assessment expectations, and immunogenicity considerations for generic filings of semaglutide, tirzepatide, and 15 other approved peptide products where patents will expire in the coming decade. The 17-peptide update is the most significant FDA generic-peptide policy activity since the 2023 Peptide Guidance Update and lands as the semaglutide patent cliff (2031 loss of exclusivity in major markets) plus tirzepatide's earliest generic entry window (December 2027 for one composition claim, later for others) begin to shape U.S. generic-manufacturer investment decisions. The Indian semaglutide patent expired March 2026, and licensed generics from Biocon, Dr. Reddy's, Sun Pharma, and others followed within weeks; Nomura Research projected the Indian semaglutide generic market at ₹12,000 crore over five years. The FDA guidance is expected to shape U.S. Abbreviated New Drug Application (ANDA) filings post-patent-expiry and represents one of the more consequential regulatory clarifications for peptide biosimilar and generic pathways in years.