PEPTIDEREPORT

Best for Weight loss

Best Peptides for Weight Loss

This page summarizes what public source records show about peptides most frequently studied and discussed for weight loss. Each entry is ranked by the depth of clinical evidence and current regulatory status — not by popularity or social media attention. This is an evidence curation, not a recommendation to take any compound. No dosing, purchasing, or treatment guidance is provided.

Last reviewed 2026-07-08 Next review 2026-08-08 20 sources
# Compound Evidence level Why it's listed
1 Tirzepatide
Evidence review Peer reviewed (Phase 3) FDA-approved for chronic weight management with the largest published Phase 3 weight loss results in the class.
2 Semaglutide
Evidence review Peer reviewed (Phase 3 + CV outcomes) FDA-approved for chronic weight management with long-term cardiovascular outcomes data unique in the class.
3 Retatrutide
Regulatory watch Peer reviewed (Phase 2 only) Investigational triple-agonist with the most promising Phase 2 weight loss data, but no FDA approval and no Phase 3 results yet.

Tirzepatide

Tirzepatide

FDA-approved for chronic weight management with the largest published Phase 3 weight loss results in the class.

Evidence level: Peer reviewed (Phase 3)

Regulatory status: FDA-approved (Zepbound for weight management, Mounjaro for Type 2 diabetes)

Tirzepatide (Mounjaro/Zepbound) is a dual GIP/GLP-1 receptor agonist FDA-approved for Type 2 diabetes (2022) and chronic weight management (2023). The SURMOUNT-1 Phase 3 trial, published in NEJM, demonstrated mean weight loss of 22.5% at 72 weeks at the highest dose — the largest published weight loss result among currently available GLP-1 class drugs. The SURPASS-2 trial also showed superior A1C reduction versus semaglutide in Type 2 diabetes, though that comparison should not be generalized to weight loss. Ongoing trials are evaluating cardiovascular outcomes, sleep apnea, and MASH indications.

Semaglutide

Semaglutide

FDA-approved for chronic weight management with long-term cardiovascular outcomes data unique in the class.

Evidence level: Peer reviewed (Phase 3 + CV outcomes)

Regulatory status: FDA-approved (Wegovy for weight management, Ozempic for Type 2 diabetes)

Semaglutide (Ozempic/Wegovy/Rybelsus) is a GLP-1 receptor agonist FDA-approved for Type 2 diabetes (2017) and chronic weight management (2021). The STEP 1 Phase 3 trial, published in NEJM, showed mean weight loss of 14.9% at 68 weeks. The SELECT cardiovascular outcomes trial demonstrated reduced major adverse cardiovascular events in non-diabetic patients with obesity — a landmark result unique among GLP-1 weight loss drugs. The SUSTAIN-6 trial previously established cardiovascular safety in Type 2 diabetes. Semaglutide is one of the most prescribed drugs globally and has generated extensive public discussion about weight loss, metabolic health, and compounded alternatives.

Retatrutide

Retatrutide

Investigational triple-agonist with the most promising Phase 2 weight loss data, but no FDA approval and no Phase 3 results yet.

Evidence level: Peer reviewed (Phase 2 only)

Regulatory status: Not FDA-approved — investigational, Phase 3 ongoing

Retatrutide is an investigational triple GLP-1/GIP/glucagon receptor agonist developed by Eli Lilly. The Phase 2 trial, published in NEJM, showed dose-dependent weight loss up to 17.5% at 48 weeks — notable for a Phase 2 result, but requiring Phase 3 confirmation. Retatrutide is not FDA-approved for any indication. The TRIUMPH Phase 3 program is ongoing, and regulatory watch status is maintained until Phase 3 data and FDA decisions are available. Despite high online attention from fitness and biohacking communities — including YouTube videos with hundreds of thousands of views — clinical evidence remains limited to Phase 2 data, and social media claims should not be conflated with approved use.

Editorial note

Rankings reflect the strength of published clinical evidence and FDA approval status as of the last reviewed date. investigational compounds rank below FDA-approved ones regardless of online hype. Update this page when Phase 3 results are published or regulatory status changes.

Sources on this page

Source records are stored in the repo and linked from this page.

Retatrutide for Obesity — A Phase 2 Trial

New England Journal of Medicine · Peer reviewed · 2023-06-26 · accessed 2026-07-01

Phase 2 randomized trial of retatrutide (LY3437943), a triple GLP-1/GIP/glucagon receptor agonist, showing dose-dependent weight loss up to 17.5% at 48 weeks in adults with obesity.

TRIUMPH Phase 3 Trial Program for Retatrutide — ClinicalTrials.gov

ClinicalTrials.gov / U.S. National Library of Medicine · Primary regulatory · 2023-07-01 · accessed 2026-07-01

ClinicalTrials.gov registry entry for the TRIUMPH Phase 3 trial program evaluating retatrutide for obesity, sponsored by Eli Lilly. Retatrutide is not FDA-approved for any indication.

Dr. Explains Why Retatrutide is KING of Fat Loss Peptides

YouTube — This Is Not Covered - Dr. Ashley Froese · Community discussion · 2026-03-05 · accessed 2026-07-01

High-view (600K+ views) YouTube explainer using strong outcome language about retatrutide for fat loss. Tracked as a media signal for high-attention claims.

Warning Letter: Gram Peptides

U.S. Food and Drug Administration · Primary regulatory · 2026-03-31 · accessed 2026-06-30

FDA warning letter discussing peptide products marketed online and the limits of research-use-only positioning.