Weight Loss Peptides

Semaglutide is an FDA-approved GLP-1 receptor agonist marketed as Ozempic for type 2 diabetes and Wegovy for chronic weight management. In August 2025, it received accelerated approval for MASH (metabolic-associated steatohepatitis) with liver fibrosis. An oral formulation (Oral Wegovy) was approved in December 2025, launching in January 2026. Clinical trials demonstrated an average weight loss of 15% over 68 weeks with injectable Wegovy, and 16.6% with oral Wegovy. The medication works by mimicking GLP-1, a natural hormone that regulates blood sugar and appetite.

Tirzepatide is a dual-action peptide approved by the FDA as Mounjaro for type 2 diabetes and Zepbound for weight management. In December 2024, Zepbound became the first and only medication approved for moderate-to-severe obstructive sleep apnea (OSA) in adults with obesity. It is the first medication to target both GIP and GLP-1 receptors simultaneously. In the SURMOUNT-1 trial, participants achieved an average weight loss of 22.5% over 72 weeks.

Retatrutide is a novel triple-receptor agonist developed by Eli Lilly currently in Phase 3 clinical trials. It has demonstrated unprecedented weight loss results, with patients losing an average of 28.7% of body weight in 48-week trials. The peptide works by simultaneously activating three metabolic pathways: GIP (glucose-dependent insulinotropic polypeptide), GLP-1 (glucagon-like peptide-1), and glucagon receptors. This multi-pronged approach appears to produce superior weight loss compared to existing FDA-approved medications. In the Phase 3 TRIUMPH-4 trial (December 2025), patients on the 12mg dose lost an average of 28.7% of body weight over 68 weeks, with 39.4% of participants achieving 30% or greater weight loss. An NDA submission to the FDA is expected in late 2026.

AOD-9604 is a modified peptide fragment of the C-terminus of human growth hormone (amino acids 176-191). It was designed to retain the fat-burning properties of HGH while avoiding effects on blood sugar and insulin sensitivity. Despite promising early research, Phase 2 clinical trials failed to demonstrate significant weight loss compared to placebo, and it was never approved by the FDA.