Weight loss peptides
Peptides studied for appetite, incretin biology, and metabolic regulation. Some are approved drugs; others are investigational or speculative.
S is approval-grade evidence; F is documented harm or near-zero human data. Each bar is how many peptides on this page land in that tier — a fast read on how much of this category sits in approval-grade evidence versus thin or vendor-driven claims.
The category at a glance
Every compound here ranked S–F by its weighted evidence score — strongest human / approval-grade evidence at the top, thin or vendor-driven claims at the bottom. Tap any row for the evidence read. Popularity never raises a tier.
Receipts, not vendor theater. Every tier here is computed from published evidence and regulatory status — not vendor marketing or influencer claims. See how we score.
SSemaglutideStrong human evidenceLow overstatementFDA-approved95/ 100
A GLP-1 receptor agonist with large randomized human trials behind it. The STEP program studied it for chronic weight management and SUSTAIN for type-2 diabetes; it is FDA-approved (Wegovy, Ozempic). The strongest weight/glucose evidence of any compound in this space — with well-documented GI side effects and the need for ongoing use.
Tier read: strong human evidence · low overstatement risk · low search interest · Approved use. Why not A: supported by human evidence, preclinical depth, mechanism confidence, safety clarity, regulatory clarity, practical relevance.
Read the full Semaglutide profile →SLiraglutideStrong human evidenceLow overstatementFDA-approved93/ 100
An earlier once-daily GLP-1 agonist, FDA-approved (Saxenda for weight, Victoza for diabetes) on the strength of the SCALE and LEAD programs. Solid human evidence, generally a smaller average weight effect than the newer weekly agents.
Tier read: strong human evidence · low overstatement risk · low search interest · Approved use. Why not A: supported by human evidence, preclinical depth, mechanism confidence, safety clarity, regulatory clarity, practical relevance.
Read the full Liraglutide profile →STirzepatideStrong human evidenceLow overstatementFDA-approved92/ 100
A dual GIP/GLP-1 receptor agonist with large randomized trials (SURMOUNT for weight, SURPASS for diabetes). FDA-approved as Mounjaro and Zepbound; program data show among the largest average weight reductions reported for a drug. Strongly evidenced, with the same GI-tolerability and continued-use caveats as other incretins.
Tier read: strong human evidence · low overstatement risk · low search interest · Approved use. Why not A: supported by human evidence, preclinical depth, mechanism confidence, safety clarity, regulatory clarity, practical relevance.
Read the full Tirzepatide profile →BRetatrutideStrong human evidenceLow overstatementInvestigational68/ 100
An investigational triple agonist (GIP/GLP-1/glucagon). A phase-2 randomized trial reported large weight reductions, but it is not approved and lacks the long-term phase-3 safety record of semaglutide and tirzepatide. Promising early human data, still investigational.
Tier read: strong human evidence · low overstatement risk · low search interest · Clinical trials. Why not C: supported by human evidence, preclinical depth, mechanism confidence, practical relevance. Why not A: held back by regulatory clarity.
Read the full Retatrutide profile →CCagrilintideModerate human evidenceLow overstatementInvestigational53/ 100
A long-acting amylin analogue (Novo Nordisk) for weight management. A randomized, placebo- and active-controlled phase-2 dose-finding trial showed significant, dose-dependent weight reduction with good tolerability — real human evidence, still pre-approval.
Tier read: moderate human evidence · low overstatement risk · low search interest · Clinical trials. Why not D: supported by its overall evidence profile. Why not B: held back by regulatory clarity.
Read the full Cagrilintide profile →CCagrisemaModerate human evidenceLow overstatementInvestigational53/ 100
The fixed combination of the amylin analogue cagrilintide with semaglutide. A randomized phase-2 trial in type-2 diabetes showed greater weight loss and HbA1c reduction than either component alone, supporting phase-3 development. Promising human data; still investigational.
Tier read: moderate human evidence · low overstatement risk · low search interest · Clinical trials. Why not D: supported by its overall evidence profile. Why not B: held back by regulatory clarity.
Read the full Cagrisema profile →DAOD 9604Early human evidenceMedium overstatementResearch-use-only41/ 100
A synthetic fragment of the C-terminus of hGH studied for fat-metabolizing (lipolytic) effects. Despite early interest, later human obesity trials (including a Phase IIb) failed to show clinically meaningful weight loss versus placebo, and it was never approved.
Tier read: early human evidence · medium overstatement risk · low search interest · Early human. Why not F: supported by its overall evidence profile. Why not C: held back by human evidence, safety clarity, regulatory clarity, practical relevance.
Read the full AOD 9604 profile →F5 Amino 1MQWeak human evidenceHigh overstatementResearch-use-only15/ 100
A small-molecule NNMT inhibitor investigated for adipocyte metabolism and obesity. The evidence is preclinical: NNMT inhibitors reduced bodyweight and fat mass in diet-induced obese mice, with no human clinical trials reported.
Tier read: weak human evidence · high overstatement risk · low search interest · Mechanism. Why not D: held back by human evidence, preclinical depth, safety clarity, regulatory clarity, practical relevance.
Read the full 5 Amino 1MQ profile →Weight-loss peptides are the most evidence-rich category in this entire database — but almost all of that evidence sits with a handful of approved incretin drugs, not the broader field. The gap between “a GLP-1 drug with large randomized trials” and “a research peptide people discuss online” is enormous, and it's the single most important thing a beginner can learn here.
Start with the best-supported options: Semaglutide, Tirzepatide, Liraglutide. Then compare them before exploring research-only compounds.
What the evidence actually supports
The strongest lane is the incretin class: GLP-1 receptor agonists (semaglutide, liraglutide), the dual GIP/GLP-1 agonist tirzepatide, and the investigational triple agonist retatrutide. These act on appetite and metabolic biology and are backed by large human trials (the STEP and SURMOUNT programs, among others). Approved members are the only weight-loss compounds here with strong human efficacy and a documented safety label.
Where the hype outruns the data
Many “fat-loss peptides” sold online — AOD-9604, fragment 176-191, and various GH-axis compounds — have weak or failed human weight-loss results despite confident marketing. Approved incretins are not a wellness supplement either: they're prescription drugs with real side effects, real contraindications, and no proven anti-aging benefit. Effortless fat loss without lifestyle change is not what the trials showed.
FAQ
What's the most evidence-backed peptide for weight loss?
The approved incretin drugs — semaglutide and tirzepatide — have the strongest human-trial evidence by a wide margin. Retatrutide shows very large signals but is still investigational.
Are research-only fat-loss peptides proven?
No. Compounds like AOD-9604 have largely disappointing or failed human weight-loss data. Treat strong online claims with caution and check the tier and evidence stage on each profile.
Is this medical or dosing advice?
No. This is a research reference. It does not provide dosing, protocols, or a recommendation to use any compound.
Research reference only. Not medical advice, treatment instructions, or a purchase recommendation. Consult a licensed professional.