Tirzepatide is a 39-amino acid dual GIP and GLP-1 receptor agonist approved by FDA under brand names Mounjaro (type 2 diabetes) and Zepbound (chronic weight management). Manufactured by Eli Lilly, tirzepatide was the first approved dual incretin receptor agonist with Phase 3 SURPASS and SURMOUNT trials demonstrating efficacy in glycemic control and weight reduction. Tirzepatide was cited in FDA warning letters to USApeptide.com (February 2025) for unauthorized sales, with the FDA noting that no approved applications exist for the unapproved versions offered online. The agency's September 2025 wave of 50+ warning letters specifically targeted compounders claiming their tirzepatide products were generic versions or contained the same active ingredient as FDA-approved products. Only FDA-registered manufacturers with approved applications may legally distribute tirzepatide.
Directory listing last reviewed July 2026.