Age and research-use confirmation
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Retatrutide, Triple incretin receptor agonist
A once weekly triple agonist of the GLP-1, GIP, and glucagon receptors, the glucagon arm distinguishing it from dual agonists by raising energy expenditure.
Shop this peptideMechanism of action
A single molecule hitting three metabolic receptors at once. The added glucagon arm raises energy burn on top of the appetite control of GLP-1/GIP, driving the largest trial weight losses yet.
Also studied
The glucagon arm adds energy expenditure and fat oxidation on top of GLP-1/GIP satiety, the proposed reason it outperforms dual agonists.
See related compoundsGLP-1 and GIP drive glucose dependent insulin secretion; Phase 3 diabetes data show large HbA1c reductions.
See related compoundsStill in Phase 3 as of mid-2026; it warrants glycemic and heart rate monitoring, and any product sold now is pre approval.
See related compoundsApplications
Weight reduction
Phase 2 + Phase 3 (TRIUMPH)
Glycemic control
Phase 3 (TRANSCEND)
Hepatic fat
Phase 2a
Bars indicate how far the evidence has progressed (in vitro to animal to human), not the size of any effect.
Compound data
Literature
Jastreboff AM, et al.
Key finding
In a Phase 2 trial (338 adults), once weekly retatrutide produced up to ~24% mean body weight reduction at 48 weeks, among the largest losses reported for a pharmacotherapy.
Full profile
The best evidenced compound on the storefront by a wide margin. Eli Lilly's Phase 3 TRIUMPH (obesity) and TRANSCEND (diabetes) programs are large and double blind. TRANSCEND-T2D-1 (537 adults, The Lancet 2026) met its primary endpoint with HbA1c reductions up to ~2.0%; TRIUMPH-1 (obesity, reported May 2026) reported average weight loss ~28% at 12 mg. Still investigational.
AE profile consistent with the GLP-1 class, predominantly dose dependent GI (nausea, vomiting, diarrhea, constipation). A retatrutide specific dysesthesia (altered skin sensation) signal is worth watching. The glucagon arm warrants glycemic and heart rate monitoring. Gray market use without titration or monitoring is especially hazardous, this is an investigational pharmaceutical with drug level effects, not a 'wellness peptide.'
Personal/family history of medullary thyroid carcinoma or MEN2; pregnancy; history of pancreatitis; caution with other glucose lowering agents.
Not yet FDA approved as of mid-2026, investigational, Phase 3 ongoing. Any retatrutide sold now is pre approval (gray market or compounded), with full quality risk. WADA: prohibited (S0 + GLP-1 class).
Once weekly subcutaneous; clinical protocols use slow titration (e.g., 2-4 mg start, escalating over months) to manage GI tolerability.
Source: Fnx Performance Peptide Research Database, a synthesis of the scientific and regulatory literature, not medical advice. Anyone considering these compounds should consult a qualified physician.
For Research Use Only. Not for human or animal consumption. These statements have not been evaluated by the FDA. Products are not intended to diagnose, treat, cure, or prevent any disease.
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