Weight Loss Peptides
Independent, evidence-based guides to the GLP-1 and related peptides that have transformed obesity treatment. No hype — just what the clinical data actually shows.
Semaglutide
FDA ApprovedGLP-1 receptor agonist
~15%
avg. weight loss
Semaglutide was the first GLP-1 drug to demonstrate weight loss approaching that of bariatric surgery. FDA-approved for chronic weight management since 2021 (Wegovy). Now also available in an oral formulation approved for weight loss (January 2026) and a higher-dose 7.2 mg formulation — Wegovy HD — approved March 2026.
Brand names: Wegovy · Ozempic · Rybelsus
Tirzepatide
FDA ApprovedGLP-1 + GIP dual agonist
~22.5%
avg. weight loss
Tirzepatide targets both GLP-1 and GIP receptors, delivering substantially greater weight loss than semaglutide alone. FDA-approved for weight management (Zepbound) in 2023. The SURMOUNT-1 trial showed nearly one-quarter of body weight lost on average.
Brand names: Zepbound · Mounjaro
Retatrutide
Phase 3 TrialsGLP-1 + GIP + Glucagon triple agonist
~28.7%
avg. weight loss
Retatrutide is Eli Lilly's triple agonist in Phase 3 development. By activating three hormone receptors, it has shown the highest weight loss of any peptide in trials to date — potentially approaching outcomes seen with bariatric surgery. Not yet FDA-approved.
Brand names: Investigational (no brand name yet)
Orforglipron
FDA ApprovedGLP-1 receptor agonist (small molecule, oral)
~15%
avg. weight loss
Orforglipron (Foundayo) is the first oral small-molecule GLP-1 receptor agonist approved for weight loss, marking a breakthrough in how GLP-1 therapy is delivered. FDA-approved April 1, 2026 — no injections, no fasting requirements, just a daily pill. Weight loss is comparable to injectable semaglutide (~15%).
Brand names: Foundayo (Eli Lilly)