Retatrutide Testing
Triple agonist targeting GIP, GLP-1, and glucagon receptors (LY3437943). In Phase 3 for obesity.
Mechanism of action
Triple agonist of GIP, GLP-1, and glucagon receptors (LY3437943). Adding glucagon activity contributes hepatic fat reduction and energy expenditure on top of incretin-driven satiety and insulin response. Phase 2 weight-loss data: ~24% at 48 weeks with the 12 mg dose.
Research areas
- ●Obesity (Phase 3 TRIUMPH program)
- ●MASH/NASH
- ●Type 2 diabetes
- ●Cardiometabolic disease
Dosing in the literature
Phase 2: 1, 4, 8, 12 mg weekly. Research material commonly sold at 10 mg/vial. Apollo data: median compounded purity ~84%, with frequent contamination from related synthesis intermediates.
For research/informational purposes only — not medical advice.
What we test on Retatrutide
Without a pharmaceutical reference, identity confirmation relies on (1) intact mass within 5 ppm of theoretical, (2) full MS/MS sequence coverage with confirmed Aib positions, and (3) co-injection studies where comparator material is available. Purity by RP-HPLC, aggregation by SEC, free diacid quantified separately.
- ✓RP-HPLC purity (UV 214 nm)
- ✓LC-MS/MS identity (Orbitrap)
- ✓Counter-ion / residual TFA
- ✓Water content (KF)
- ✓Endotoxin (LAL, USP <85>)
Common impurities & failure modes
- Truncated sequences (multiple positions)
Long synthesis (39 residues, multiple non-natural amino acids) produces many possible failure points.
- Free fatty acid
From incomplete acylation.
- Diastereomers from racemization
Long coupling times at certain residues drive epimerization; chiral analysis recommended.
- Aggregates
Lipidated peptide forms micelles in solution; SEC-HPLC quantifies aggregate fraction.
Regulatory status
Investigational (Eli Lilly, Phase 3 as of 2025).