Goal guide

Peptides for weight loss

Weight loss is the one goal where some peptides have strong human evidence, because the GLP-1 class includes approved medicines with large trials behind them. Others marketed for fat loss have far weaker support. Sorting them by evidence is the most useful thing this page can do.

Reviewed for accuracy · Last reviewed July 7, 2026

What peptides are studied for weight loss?

The compounds below are the ones most discussed for weight loss. Each links to its full profile, where the dosing, side effects, and sources live. They are ordered roughly by how much human evidence sits behind them, not by a claim that any one works.

What to weigh

The gap between the top and bottom of this list is large. The GLP-1 class (tirzepatide, semaglutide) has approved labels and Phase 3 evidence, while AOD-9604 has human trials that did not demonstrate meaningful weight loss. Retatrutide sits in between: promising Phase 2 data but no approval.

For the approved GLP-1 peptides, most people sourcing vials independently rather than as a prescribed pen need to convert milligrams to insulin-syringe units, which the compound pages and calculators cover. Independently sourced material of any of these carries no guarantee of the testing a regulated product does.

FAQ

What is the best peptide for weight loss?By weight of evidence, the FDA-approved GLP-1 peptides (tirzepatide and semaglutide) are the strongest-supported. Retatrutide shows promising Phase 2 data but is investigational, and compounds like AOD-9604 have weak human efficacy evidence.
Does AOD-9604 work for weight loss?The human evidence does not support it. Its obesity trials did not show meaningful weight loss versus placebo, even though mouse studies suggested fat-oxidation effects.

References

  1. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1)New England Journal of Medicine · 2022 · PMID 35658024 · DOI 10.1056/NEJMoa2206038
  2. Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1)New England Journal of Medicine · 2021 · PMID 33567185 · DOI 10.1056/NEJMoa2032183
  3. Triple-Hormone-Receptor Agonist Retatrutide for Obesity: A Phase 2 TrialNew England Journal of Medicine · 2023 · PMID 37366315 · DOI 10.1056/NEJMoa2301972
  4. Safety and Tolerability of the Hexadecapeptide AOD9604 in HumansJournal of Endocrinology and Metabolism · 2013 · DOI 10.4021/jem157w

This page is an independent educational reference and is not medical advice, and does not indicate any approval status for any use. Talk to a doctor before starting any compound.