Retatrutide is an investigational triple agonist (GIP + GLP-1 + glucagon); semaglutide is an FDA-approved GLP-1 single agonist. In their own trials, retatrutide reached ~24.2% mean weight reduction at 48 weeks (Phase 2) versus semaglutide’s ~14.9% at 68 weeks (STEP-1). They have never been tested head-to-head , and only semaglutide is approved.

No head-to-head trial exists. The figures below come from separate studies with different populations, durations, doses and endpoints. Cross-trial percentages are indicative only — they are not evidence that one compound outperforms another. All data is presented for research context; nothing here is medical or dosing guidance.

At a glance

Retatrutide Semaglutide Receptor targets GIP + GLP-1 + glucagon (triple) GLP-1 only (single) Developer Eli Lilly (LY3437943) Novo Nordisk (Ozempic / Wegovy) Trial stage Phase 3 (TRIUMPH) ongoing FDA-approved Headline weight data ~24.2% at 48 wk (Phase 2, 12 mg) ~14.9% at 68 wk (STEP-1) Dosing cadence Once-weekly (trials) Once-weekly (also oral form) Approval None yet (investigational) Type 2 diabetes & weight management

One receptor vs three

Semaglutide is the reference GLP-1 mono-agonist — it acts on a single incretin receptor and set the modern benchmark for the class. Retatrutide layers GIP and glucagon agonism on top of GLP-1.

Semaglutide — single

GLP-1 receptor only. The most studied, most prescribed molecule in the class, with the deepest long-term dataset.

Retatrutide — triple

GIP + GLP-1 + glucagon. Broader receptor engagement, larger early weight numbers, but far less long-term evidence.

What the trials showed

Retatrutide (Phase 2, NEJM 2023): up to 24.2% mean weight reduction at 48 weeks (12 mg), still rising at trial end. Phase 3 TRIUMPH-1 has reported reductions up to ~28% at 80 weeks.

Semaglutide (STEP-1, Phase 3): mean weight reduction of ~14.9% at 68 weeks at 2.4 mg — the result that reset expectations for GLP-1 therapy.

The cross-trial gap looks large, but semaglutide’s numbers come from a completed, approved programme, while retatrutide’s come from earlier-phase research still being confirmed. Depth of evidence and regulatory status weigh against a raw percentage.

Regulatory status

Semaglutide is FDA-approved (Ozempic for type 2 diabetes, Wegovy for weight management, plus an oral form). Retatrutide is investigational with no approval and is a research compound only.

Side-effect profiles

Both are dominated by dose-dependent gastrointestinal effects that ease with gradual titration in trials. Semaglutide’s safety profile is the most mature in the class thanks to years of post-approval use. Retatrutide trials additionally flagged heart-rate increases and glucagon-arm metabolic parameters that Phase 3 is designed to characterise.

Research takeaway

Retatrutide = triple agonist, investigational, largest early weight numbers.

Semaglutide = GLP-1 mono-agonist, approved, deepest evidence base.

No head-to-head data — the percentage gap is cross-trial, not a verdict.

Both are supplied by New-U strictly as research compounds.

Retatrutide & semaglutide, lab-direct

New-U supplies both as >99% HPLC-verified research compounds with a per-batch Certificate of Analysis. Research use only — not for human consumption.

Frequently asked questions

Is retatrutide stronger than semaglutide?

In their separate trials retatrutide reached ~24.2% mean weight reduction at 48 weeks versus semaglutide’s ~14.9% at 68 weeks, but no head-to-head trial exists, so this is a cross-trial comparison only. Semaglutide is approved with mature data; retatrutide is investigational. Research context only.

What is the difference between retatrutide and semaglutide?

Semaglutide is a single GLP-1 receptor agonist; retatrutide is a triple agonist adding GIP and glucagon receptors. Semaglutide is FDA-approved; retatrutide is still in Phase 3 trials.

Is retatrutide approved like Ozempic or Wegovy?

No. Semaglutide (Ozempic, Wegovy) is FDA-approved. Retatrutide has no approval and is an investigational research compound.

Do retatrutide and semaglutide have the same side effects?

Both are dominated by dose-dependent gastrointestinal effects. Semaglutide has the more mature safety record; retatrutide trials additionally noted heart-rate increases and glucagon-arm parameters being characterised in Phase 3.

All figures are laboratory-preparation reference points, not dosing guidance. New-U Research Compounds supplies bacteriostatic water and research compounds strictly for laboratory research use only — not for human consumption .

Research-grade · >99% HPLC purity · COA per lot

Buy Semaglutide from New-U Research Compounds

Lab-verified by Janoshik Analytical (RP-HPLC + ESI-MS), sealed vials, discreet tracked worldwide shipping. For laboratory research use only — not for human consumption.

PRECISION. PURITY. PERFORMANCE.

Research peptides at >99% HPLC-verified purity, third-party tested by Janoshik Analytical & Freedom Diagnostics, with Certificates of Analysis published per released batch. Supplied strictly for laboratory research use.

Shop

All research compounds

Price list

Where to buy peptides

Research

Support

Ways to Pay

Shop by goal

Muscle & IGF Research

Tissue and Cellular Models

Regenerative Research

Cellular Senescence Research

Cognitive Research

Multi-Compound Blends

Shop by compound

CJC-1295 (without DAC)

Shop by region

Research use only (RUO). All products are sold strictly for laboratory and research purposes — not for human or veterinary consumption. Purchasers must be 21 or older.

Website & business operated by Hilxera Distribution Services LLC. Registered in Wyoming, ID: 2026-001928701.

Research use only — not for human consumption. All products are supplied strictly for laboratory research purposes.

Retatrutide vs Semaglutide: Triple Agonist vs GLP-1, Compared

On this page