Compare peptides side-by-side
Pick any two peptides to compare their evidence quality, FDA approval status, research scores, risks, and indications. All data sourced from the SmartPeptide library.
Educational only — not medical advice. SmartPeptide does not prescribe, diagnose, or treat. Always consult a licensed healthcare provider before using any peptide, supplement, medication, or protocol.
Tirzepatide
Dual GIP / GLP-1 receptor agonist with strong Phase 3 evidence in type 2 diabetes (SURPASS) and obesity (SURMOUNT).
Full pageSURMOUNT-1 (n=2,539) showed up to ~22.5% body-weight reduction at 72 weeks at the 15 mg dose. SURPASS trials demonstrated robust HbA1c improvement vs comparators in type 2 diabetes.
Direct head-to-head with semaglutide for cardiovascular outcomes is still maturing. Long-term durability of weight loss after discontinuation remains under study.
Similar profile to GLP-1 agonists. Prescription-only.
GI side effects, injection-site reactions.
Retatrutide
Eli Lilly's triple agonist (GLP-1 / GIP / glucagon receptor). Currently the most potent weight-management investigational drug — Phase 2 trials reported ~24% body weight reduction at the highest dose. Phase 3 TRIUMPH program ongoing. Not yet FDA-approved.
Full pagePhase 2 trial (n≈338, 48 weeks): ~24.2% mean body weight reduction at 12 mg weekly vs. ~2.1% placebo. Type 2 diabetes Phase 2 showed superior HbA1c reduction vs. dulaglutide. Phase 3 TRIUMPH program is ongoing across weight management, T2D, MASH, and cardiovascular outcomes.
All commercial availability — Retatrutide is investigational and NOT FDA-approved as of mid-2026. Long-term cardiovascular and oncologic safety, durability after stopping, and pediatric use are all open questions awaiting Phase 3 read-outs (expected 2026-2027).
GI side effects (nausea, vomiting, diarrhea) — class-typical for incretin agonists, often dose-limiting. Theoretical concerns about glucagon receptor activation effects on glucose regulation, lipid metabolism, and liver function are being evaluated in Phase 3. Not yet approved — long-term safety unknown.
Nausea (most common), vomiting, diarrhea, constipation, decreased appetite, injection-site reactions. Some studies note slightly elevated heart rate vs. semaglutide.