Best 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.
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 (Mounjaro for Type 2 diabetes; Zepbound for weight management and moderate-to-severe obstructive sleep apnea in adults with obesity)
Tirzepatide (Mounjaro/Zepbound) is a dual GIP/GLP-1 receptor agonist FDA-approved for Type 2 diabetes, chronic weight management, and moderate-to-severe obstructive sleep apnea in adults with obesity. The SURMOUNT-1 Phase 3 trial reported mean weight loss of 22.5% at 72 weeks at the highest dose. SURPASS-CVOT later found tirzepatide noninferior to dulaglutide for major adverse cardiovascular events in adults with Type 2 diabetes and established atherosclerotic cardiovascular disease. These results apply to their trial populations and do not establish an individual treatment choice.
Phase 3 trial of tirzepatide for obesity showing mean weight loss of 22.5% at 72 weeks at the highest dose.
nejm-tirzepatide-surmount1-2022Head-to-head trial showing tirzepatide superior to semaglutide for A1C reduction in Type 2 diabetes.
nejm-tirzepatide-surpass2-2021ClinicalTrials.gov registry for the SURMOUNT-1 Phase 3 trial of tirzepatide for obesity, sponsored by Eli Lilly.
clinicaltrials-gov-surmount1ClinicalTrials.gov registry for SURMOUNT-4, evaluating tirzepatide for extended obesity treatment.
clinicaltrials-gov-surmount4FDA approval of Mounjaro (tirzepatide) injection for Type 2 diabetes, NDA 215866.
fda-mounjaro-approval-2022FDA approved Zepbound (tirzepatide) in November 2023 for chronic weight management in adults with obesity, used with diet and exercise. NDA 217806.
fda-zepbound-approval-2023FDA approval announcement adding moderate-to-severe obstructive sleep apnea in adults with obesity to Zepbound's indications.
fda-zepbound-osa-approval-2024SURPASS-CVOT publication reporting that tirzepatide was noninferior to dulaglutide for major adverse cardiovascular events in adults with Type 2 diabetes and established atherosclerotic cardiovascular disease.
pubmed-surpass-cvot-2025Semaglutide
FDA-approved for chronic weight management with a completed cardiovascular outcomes trial and a cardiovascular-risk-reduction indication for Wegovy.
Evidence level: Peer reviewed (Phase 3 + CV outcomes)
Regulatory status: FDA-approved (Ozempic for Type 2 diabetes; Wegovy for weight management and cardiovascular-risk reduction in the labeled population)
Semaglutide is a GLP-1 receptor agonist. Ozempic is FDA-approved for Type 2 diabetes, and Wegovy is approved for chronic weight management. FDA added an indication for Wegovy to reduce the risk of cardiovascular death, heart attack, and stroke in adults with established cardiovascular disease and either obesity or overweight. The STEP 1 Phase 3 trial reported mean weight loss of 14.9% at 68 weeks. SELECT studied adults with established cardiovascular disease and obesity or overweight and reported fewer major adverse cardiovascular events with semaglutide than placebo.
Phase 3 trial showing semaglutide 2.4 mg weekly achieved mean weight loss of 14.9% at 68 weeks.
nejm-semaglutide-step1-2021Cardiovascular outcomes trial showing semaglutide reduced major adverse CV events in non-diabetic patients with obesity.
nejm-semaglutide-select-2023Pre-specified CV outcomes trial establishing cardiovascular safety of semaglutide in Type 2 diabetes.
nejm-semaglutide-sustain6-2016ClinicalTrials.gov registry for STEP 1, the pivotal semaglutide obesity trial.
clinicaltrials-gov-step1ClinicalTrials.gov registry for the SELECT cardiovascular outcomes trial of semaglutide.
clinicaltrials-gov-selectClinicalTrials.gov registry for SUSTAIN-6, establishing CV safety of semaglutide in Type 2 diabetes.
clinicaltrials-gov-sustain6FDA approval of Ozempic (semaglutide) injection for Type 2 diabetes, NDA 209637.
fda-ozempic-approval-2017FDA approval of Wegovy (semaglutide 2.4 mg) injection for chronic weight management, NDA 215256.
fda-wegovy-approval-2021FDA announcement of the cardiovascular risk-reduction indication for Wegovy in eligible adults.
fda-wegovy-cardiovascular-indication-2024Retatrutide
Investigational triple agonist with randomized Phase 2 evidence and sponsor-reported Phase 3 obesity results, but no FDA approval.
Evidence level: Peer reviewed Phase 2; sponsor Reported Phase 3 obesity results
Regulatory status: Investigational and not FDA-approved
Retatrutide is an investigational triple GIP, GLP-1, and glucagon receptor agonist developed by Eli Lilly. In the Phase 2 obesity trial, the 12 mg group had a mean body-weight change of -17.5% at week 24 and -24.2% at week 48. Lilly reported up to -28.3% at week 80 in TRIUMPH-1, but a full peer-reviewed obesity publication was not available at the July 12, 2026 review cutoff. Retatrutide is not FDA-approved, and sponsor results do not replace a regulatory review.
Retatrutide phase 2 obesity trial (NEJM 2023): at 12 mg, mean body weight fell 17.5% at week 24 and 24.2% at week 48; GI adverse events were most common.
nejm-retatrutide-phase2-2023Completed Phase 3 master protocol NCT05929066. The registry identifies TRIUMPH-1 as a randomized, double-blind, placebo-controlled study in adults without type 2 diabetes who have obesity or overweight.
clinicaltrials-retatrutide-triumph1Eli Lilly and Company. Lilly's triple agonist, retatrutide, delivered powerful weight loss in pivotal Phase 3 obesity trial. News release, 2026-05-21.
research-reta-04U.S. Food and Drug Administration. FDA's Concerns with Unapproved GLP-1 Drugs Used for Weight Loss. Accessed 2026-07-12.
research-reta-02FDA warning letter discussing peptide products marketed online and the limits of research-use-only positioning.
fda-gram-peptides-warning-2026Rankings 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.
Source records are stored in the repo and linked from this page.
Phase 3 trial of tirzepatide for obesity showing mean weight loss of 22.5% at 72 weeks at the highest dose.
nejm-tirzepatide-surmount1-2022Head-to-head trial showing tirzepatide superior to semaglutide for A1C reduction in Type 2 diabetes.
nejm-tirzepatide-surpass2-2021ClinicalTrials.gov registry for the SURMOUNT-1 Phase 3 trial of tirzepatide for obesity, sponsored by Eli Lilly.
clinicaltrials-gov-surmount1ClinicalTrials.gov registry for SURMOUNT-4, evaluating tirzepatide for extended obesity treatment.
clinicaltrials-gov-surmount4FDA approval of Mounjaro (tirzepatide) injection for Type 2 diabetes, NDA 215866.
fda-mounjaro-approval-2022FDA approved Zepbound (tirzepatide) in November 2023 for chronic weight management in adults with obesity, used with diet and exercise. NDA 217806.
fda-zepbound-approval-2023FDA approval announcement adding moderate-to-severe obstructive sleep apnea in adults with obesity to Zepbound's indications.
fda-zepbound-osa-approval-2024SURPASS-CVOT publication reporting that tirzepatide was noninferior to dulaglutide for major adverse cardiovascular events in adults with Type 2 diabetes and established atherosclerotic cardiovascular disease.
pubmed-surpass-cvot-2025Phase 3 trial showing semaglutide 2.4 mg weekly achieved mean weight loss of 14.9% at 68 weeks.
nejm-semaglutide-step1-2021Cardiovascular outcomes trial showing semaglutide reduced major adverse CV events in non-diabetic patients with obesity.
nejm-semaglutide-select-2023Pre-specified CV outcomes trial establishing cardiovascular safety of semaglutide in Type 2 diabetes.
nejm-semaglutide-sustain6-2016ClinicalTrials.gov registry for STEP 1, the pivotal semaglutide obesity trial.
clinicaltrials-gov-step1ClinicalTrials.gov registry for the SELECT cardiovascular outcomes trial of semaglutide.
clinicaltrials-gov-selectClinicalTrials.gov registry for SUSTAIN-6, establishing CV safety of semaglutide in Type 2 diabetes.
clinicaltrials-gov-sustain6FDA approval of Ozempic (semaglutide) injection for Type 2 diabetes, NDA 209637.
fda-ozempic-approval-2017FDA approval of Wegovy (semaglutide 2.4 mg) injection for chronic weight management, NDA 215256.
fda-wegovy-approval-2021FDA announcement of the cardiovascular risk-reduction indication for Wegovy in eligible adults.
fda-wegovy-cardiovascular-indication-2024Retatrutide phase 2 obesity trial (NEJM 2023): at 12 mg, mean body weight fell 17.5% at week 24 and 24.2% at week 48; GI adverse events were most common.
nejm-retatrutide-phase2-2023Completed Phase 3 master protocol NCT05929066. The registry identifies TRIUMPH-1 as a randomized, double-blind, placebo-controlled study in adults without type 2 diabetes who have obesity or overweight.
clinicaltrials-retatrutide-triumph1Eli Lilly and Company. Lilly's triple agonist, retatrutide, delivered powerful weight loss in pivotal Phase 3 obesity trial. News release, 2026-05-21.
research-reta-04U.S. Food and Drug Administration. FDA's Concerns with Unapproved GLP-1 Drugs Used for Weight Loss. Accessed 2026-07-12.
research-reta-02FDA warning letter discussing peptide products marketed online and the limits of research-use-only positioning.
fda-gram-peptides-warning-2026