Retatrutide
Triple GLP-1/GIP/Glucagon Agonist · Weight Loss & Diabetes
Novel triple hormone receptor agonist targeting GLP-1, GIP, and glucagon receptors. Phase II trials demonstrated 24.2% weight loss at 48 weeks—the highest recorded for obesity medications.
Overview
Novel triple hormone receptor agonist targeting GLP-1, GIP, and glucagon receptors. Phase II trials demonstrated 24.2% weight loss at 48 weeks—the highest recorded for obesity medications.
Activates GLP-1 for appetite suppression, GIP for insulin sensitivity, and glucagon for increased energy expenditure and hepatic fat oxidation.
Research indications
What the compound has been studied for, grouped by body system. Effect size is the reported magnitude where it was measured — not a recommendation.
Clinical trials show 17.5% weight loss at 24 weeks and 24.2% at 48 weeks.
Continuous weight loss with no plateau at 48 weeks suggests greater long-term potential.
Addresses obesity through appetite suppression, energy expenditure, and metabolic efficiency.
HbA1c reductions up to 2.16% with 82% achieving target levels below 6.5%.
Balanced glycemic control with minimal hypoglycemia risk.
Marked improvements in sensitivity with potential for reduced exogenous insulin requirements.
Non-HDL cholesterol reductions up to 26.9%, triglyceride reductions up to 40.6%.
Consistent decreases in systolic and diastolic blood pressure across trials.
Up to 82% reduction in liver fat with normalization in 90% of participants.
A large effect in a weak study and a small effect in a strong one are different things. Effect size is never evidence of use in people.
- Class
- Triple GLP-1/GIP/glucagon agonist
- Chain length
- 39 residues
- Molecular weight
- 4731.33 Da
- Half-life
- ~144 h
- Typical dose
- 0.5mg starting, titrate up to 8-12mg weekly
- Frequency
- Once weekly (same day each week)
- Cycle length
- Continuous therapy as prescribed
- Storage
- Reconstituted: 2-8°C, use within 28 days
Molecular data
- Type
- Triple GLP-1/GIP/glucagon agonist
- Molecular weight
- 4731.33 Da
- Chain length
- 39 residues
- Half-life
- 8640 min
Dosing reference
Doses reported in the literature and by suppliers. These are a record of what has been used in research — reference, never instruction.
| Context | Route | Amount | Frequency |
|---|---|---|---|
| Starting Dose (Week 1-4) | SubQ | 0.5mg | Once weekly |
| Low Maintenance (Week 4-8) | SubQ | 1mg | Once weekly |
| Escalation (Week 8-12) | SubQ | 2mg | Once weekly |
| Moderate (Week 12-16) | SubQ | 4mg | Once weekly |
| Advanced (Week 16-20) | SubQ | 8mg | Once weekly |
| Maximum Efficacy (Week 20+) | SubQ | 12mg | Once weekly |
Interactions
Do not combine with other dual/triple agonists—risk of severe hypoglycemia and excessive GI effects.
Do not combine—overlapping GLP-1 agonist mechanisms increase severe hypoglycemia risk.
Both cause significant GI effects. Not recommended without specialist supervision.
May significantly reduce insulin requirements. Monitor blood glucose and adjust insulin doses accordingly.
Safe combination tested in clinical trials. Different mechanisms work complementarily for glucose control.
Clinical trials included SGLT2 inhibitors with no safety concerns.
Safe combination; BPC-157 may provide GI protective benefits during retatrutide use.
Space oral contraceptives by 1 hour before retatrutide due to delayed gastric emptying.
Quality checklist
- ✓Pharmaceutical-grade white powder with uniform texture
- ✓Proper cold chain maintenance (2-8°C refrigeration)
- ✓Clear, colorless reconstituted solution without particles
- ✓Stable extended half-life effects (consistent appetite suppression between doses)
- !Source verification critical—counterfeit versions circulate due to investigational status
- ×Rapid tolerance or effectiveness loss suggests degraded or counterfeit product
- ×Unusual side effect profile may indicate contamination
What to expect
Safety
- Gastrointestinal effects (nausea, vomiting, diarrhea)—typically mild to moderate
- Heart rate increases—common especially in first 24 weeks
- Appetite suppression
- Mild dehydration
- Severe persistent nausea or vomiting preventing adequate nutrition
- Signs of pancreatitis: severe abdominal pain radiating to back
- Severe hypoglycemia symptoms: confusion, dizziness, sweating
- Excessive weight loss (>3 lbs per week consistently or >25% total body weight)
- Gallbladder problems: severe right upper abdominal pain
- Personal or family history of medullary thyroid carcinoma
- MEN2 syndrome
- Severe renal impairment
FAQ
What makes retatrutide's 24.2% weight loss so much higher than semaglutide's 15-20%?
Retatrutide is a triple agonist activating GLP-1, GIP, and glucagon receptors simultaneously. GLP-1 suppresses appetite, GIP improves insulin sensitivity, and glucagon increases energy expenditure and fat oxidation. Semaglutide only activates GLP-1. The triple mechanism addresses obesity through three distinct pathways, explaining the superior results.
Does retatrutide actually reduce liver fat, or just overall fat loss?
It specifically targets liver fat. Clinical trials showed up to 82% liver fat reduction and complete normalization in 90% of participants at 24 weeks. This isn't just general weight loss—it's preferential hepatic fat oxidation, making retatrutide potentially valuable for NAFLD/MASH, not just obesity.
Why is retatrutide more likely to cause gastrointestinal side effects?
Triple agonism means triple GI effects. GLP-1, GIP, and glucagon all slow gastric emptying and affect GI motility. Combining three mechanisms means more nausea, diarrhea, and vomiting, especially during dose escalation. However, most people tolerate it by week 4-8 as their body adapts.
Could I eventually stop taking retatrutide, or do I need it forever?
Unknown. Phase 2 trials ran 48 weeks—long enough to achieve 24% weight loss but not long enough to study discontinuation. Clinical experience with semaglutide suggests weight returns if stopped. Phase 3 TRIUMPH trials (results expected 2026) should provide data on maintenance therapy vs. indefinite use.
References
- 1Triple-Hormone-Receptor Agonist Retatrutide for Obesity — A Phase 2 TrialJastreboff, A.M., et al. · New England Journal of Medicine · 2023
Landmark phase 2 RCT showing dose-dependent weight loss: 24.2% at 48 weeks with 12mg dose — the highest recorded for any obesity medication at the time. Weight reduction of ≥15% achieved in 83% of 12mg recipients.
human-rctPubMed 37366315 ↗ - 2Retatrutide, a GIP, GLP-1 and glucagon receptor agonist, for people with type 2 diabetes: a phase 2 trialRosenstock, J., et al. · The Lancet · 2023
Phase 2 trial in type 2 diabetes demonstrating clinically meaningful HbA1c reductions and robust weight loss of up to 16.9% at 36 weeks, with safety profile consistent with GLP-1 receptor agonists.
reviewPubMed 37385280 ↗ - 3Triple hormone receptor agonist retatrutide for metabolic dysfunction-associated steatotic liver disease: a randomized phase 2a trialSanyal, A.J., et al. · Nature Medicine · 2024
Dose-dependent liver fat reduction: 82.4% at 12mg dose. Normal liver fat (<5%) achieved in 86% of 12mg recipients vs 0% placebo at 24 weeks. Improvements linked to changes in body weight, abdominal fat, and insulin sensitivity.
human-rctPubMed 38858523 ↗ - 4Structural insights into the triple agonism at GLP-1R, GIPR and GCGR manifested by retatrutideLi, W., et al. · Cell Discovery · 2024
Cryo-EM structures reveal how retatrutide simultaneously activates GLP-1R, GIPR, and GCGR through distinct receptor-binding modes, explaining the molecular basis for its triple agonist activity and superior clinical efficacy.
reviewPubMed 39019866 ↗ - 5TRIUMPH registrational clinical trials: Rationale and designAronne, L.J., et al. · Obesity · 2025
Phase 3 TRIUMPH program design: four multicenter, randomized, double-blind studies assessing weekly retatrutide for obesity, obstructive sleep apnea, knee osteoarthritis, and weight management in cardiovascular disease populations.
human-rctPubMed 41090431 ↗ - 6Effects of retatrutide on body composition in people with type 2 diabetes: a phase 2 substudyRosenstock, J., et al. · The Lancet Diabetes & Endocrinology · 2025
Substudy demonstrating significant total body fat mass reduction with retatrutide vs placebo and dulaglutide. Proportion of lean mass loss to total weight loss was similar to other obesity treatments.
reviewPubMed 40609566 ↗