Retatrutide: uses, evidence, cost and safety
Retatrutide is an investigational triple agonist targeting the GIP, GLP-1 and glucagon receptors. It is NOT FDA-approved and is not legally available for prescription or compounding; it exists only within clinical trials. Early phase 2 data reported large average weight reductions, but phase 3 safety and efficacy results are still needed.
What Retatrutide is
Retatrutide is a triple gip / glp-1 / glucagon receptor agonist (investigational). It is marketed as None — investigational. Retatrutide is an investigational triple agonist targeting the GIP, GLP-1 and glucagon receptors. It is NOT FDA-approved and is not legally available for prescription or compounding; it exists only within clinical trials. Early phase 2 data reported large average weight reductions, but phase 3 safety and efficacy results are still needed.
Regulatory status
INVESTIGATIONAL. Not FDA-approved. Available only through clinical trials.
How does it work?
Adds glucagon-receptor agonism to the dual-incretin mechanism, which may increase energy expenditure in addition to reducing appetite.
Clinical evidence
Mean percent body-weight change from controlled trials. Bars show trial averages over the study period; individual results vary widely and are not guaranteed. Values shown are percentage points.
Phase 2 data published in 2023 reported mean weight reductions above 20% at higher doses over 48 weeks. These are early-stage results; phase 3 trials are ongoing.
| Trial | Arm | Result | Duration | Comparator | Source |
|---|---|---|---|---|---|
| SURMOUNT-1 | Tirzepatide 15 mg | −20.9% | 72 weeks | Placebo −3.1% | NEJM 2022 (Jastreboff et al.) |
| SURMOUNT-1 | Tirzepatide 10 mg | −19.5% | 72 weeks | NEJM 2022 | |
| SURMOUNT-1 | Tirzepatide 5 mg | −15.0% | 72 weeks | NEJM 2022 | |
| SURMOUNT-5 | Tirzepatide (max tolerated) | −20.2% | 72 weeks | vs semaglutide −13.7% | NEJM 2025 (Aronne et al.) |
| STEP 1 | Semaglutide 2.4 mg | −14.9% | 68 weeks | Placebo −2.4% | NEJM 2021 (Wilding et al.) |
| STEP 8 | Semaglutide 2.4 mg | −15.8% | 68 weeks | vs liraglutide 3.0 mg −6.4% | JAMA 2022 (Rubino et al.) |
| SCALE | Liraglutide 3.0 mg | −8.0% | 56 weeks | Placebo −2.6% | NEJM 2015 |
| SELECT | Semaglutide 2.4 mg | 20% MACE reduction | ~40 months | Cardiovascular outcomes | NEJM 2023 |
Dosing and titration
See the FDA label for the approved dose schedule.
Common and serious side effects
Reported gastrointestinal effects consistent with the incretin class in phase 2; the full safety profile is not established.
Warnings and contraindications
Because retatrutide is investigational, any product sold to consumers as 'retatrutide' outside a trial is unapproved and unregulated. We do not evaluate or link to such sellers.
Frequently asked questions
Is Retatrutide FDA-approved?
INVESTIGATIONAL. Not FDA-approved. Available only through clinical trials.
How does Retatrutide work?
Adds glucagon-receptor agonism to the dual-incretin mechanism, which may increase energy expenditure in addition to reducing appetite.
What are the most common side effects of Retatrutide?
Reported gastrointestinal effects consistent with the incretin class in phase 2; the full safety profile is not established.
Who should not take Retatrutide?
Because retatrutide is investigational, any product sold to consumers as 'retatrutide' outside a trial is unapproved and unregulated. We do not evaluate or link to such sellers.
Sources
- U.S. Food and Drug Administration — prescribing information and drug labels for None — investigational.
- Pivotal randomized controlled trials as cited in the evidence section (SURMOUNT, SURPASS, STEP, SUSTAIN, SCALE as applicable).
- CMS National Plan & Provider Enumeration System — clinician verification for reviewed providers.
- ClinicalTrials.gov — trial registrations for investigational agents.