Benefits
- Unprecedented weight loss up to 24.2% of body weight at 48 weeks in phase 2 trialstrong
- Potentially superior to tirzepatide based on early comparative datapreliminary
- Significant glycemic improvement in patients with type 2 diabetesmoderate
- Marked reduction in liver fat content — potential MASH treatmentpreliminary
- Increased energy expenditure via glucagon receptor activation (beyond appetite suppression alone)moderate
Dosage Protocols
| Route | Dosage Range | Frequency | Notes |
|---|---|---|---|
| Subcutaneous injection (phase 2 low dose) | 1 mg → 4 mg | Once weekly | Dose escalation over several weeks in clinical trials. Lower doses showed clinically meaningful but more modest weight loss. |
| Subcutaneous injection (phase 2 mid dose) | 4 mg → 8 mg | Once weekly | Mid-range dosing produced approximately 22% body weight loss at 48 weeks with a favorable tolerability profile. |
| Subcutaneous injection (phase 2 high dose) | 8 mg → 12 mg | Once weekly | Highest dose tier achieving up to 24.2% weight loss. Phase 3 trials will confirm optimal dosing. |
Medical disclaimer
Dosage information is provided for educational reference only. Always follow your prescriber's instructions and consult a qualified healthcare provider before starting any peptide protocol.
Side Effects
- Nausea, especially during dose titrationcommon
- Diarrheacommon
- Vomitingcommon
- Decreased appetitecommon
- Constipationcommon
- Potential increase in heart rate (glucagon-mediated)rare
- Theoretical hepatic effects from glucagon receptor activation — monitored in trialsrare
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Articles
- Retatrutide: The Complete Guide to the Triple-Agonist PeptideA comprehensive guide to retatrutide (LY3437943), Eli Lilly's investigational triple-agonist peptide targeting GIP, GLP-1, and glucagon receptors. Covers mechanism, clinical trial results, dosing, side effects, cost, and availability.
- Retatrutide Cost: Expected Pricing, Insurance & SavingsWhat will retatrutide cost when it reaches the market? Estimated monthly pricing based on comparable GLP-1 drugs, insurance coverage outlook, savings programs, and how retatrutide compares on cost-effectiveness.
- Retatrutide Side Effects: What the Clinical Data ShowsA data-driven overview of retatrutide side effects from Phase 2 clinical trials, covering gastrointestinal symptoms, cardiovascular considerations, hepatic effects, and strategies to minimize adverse events. Based on published trial data from Jastreboff et al. (2023) and Rosenstock et al. (2023). Educational reference only — retatrutide is not yet FDA approved.
- Retatrutide Results: Weight Loss Data from Clinical TrialsDetailed breakdown of retatrutide weight loss results from phase 2 clinical trials, including dose-response data, milestone achievement rates, metabolic improvements, and how retatrutide results compare to semaglutide and tirzepatide.
Use cases
Frequently Asked Questions
When will retatrutide be FDA approved and available?
Retatrutide is currently in phase 3 clinical trials (the TRIUMPH program). Based on typical development timelines, FDA approval could come as early as late 2026 or 2027, assuming positive phase 3 results. Eli Lilly has not publicly committed to a specific approval date. Phase 3 results will be critical in determining the timeline. This is speculative and not guaranteed — always monitor official announcements from Eli Lilly and the FDA.
How does retatrutide compare to tirzepatide (Mounjaro/Zepbound)?
Retatrutide is a triple agonist (GIP/GLP-1/glucagon) while tirzepatide is a dual agonist (GIP/GLP-1). The additional glucagon receptor activation in retatrutide increases energy expenditure and fat oxidation, potentially explaining its greater weight loss (~24% vs ~21% in respective phase 2 trials). However, these are cross-trial comparisons and not head-to-head data. Phase 3 trials are needed to confirm superiority. Consult your healthcare provider for personalized recommendations.
Can I get retatrutide now before FDA approval?
Retatrutide is not commercially available and can only be obtained through enrollment in clinical trials. It is not available at compounding pharmacies, and any product sold online claiming to be retatrutide should be treated with extreme caution as it is unverified and potentially dangerous. Do not purchase research chemicals for self-administration. Check clinicaltrials.gov for active retatrutide trials you may be eligible to join.
How much will retatrutide cost when it becomes available?
Pricing has not been announced, but based on Eli Lilly's pricing for tirzepatide (Mounjaro/Zepbound), retatrutide would likely be in the range of $1,000-$1,300 per month at list price. Given its potentially superior efficacy, it could command a premium. Insurance coverage decisions will significantly impact out-of-pocket costs. This is speculation and not financial advice.
What makes retatrutide different from other weight loss drugs?
Retatrutide is unique because it is the first drug to simultaneously activate three metabolic hormone receptors (GIP, GLP-1, and glucagon). While semaglutide targets one receptor and tirzepatide targets two, retatrutide's triple mechanism attacks obesity from multiple angles: reducing appetite (GLP-1), improving insulin and fat metabolism (GIP), AND increasing energy expenditure (glucagon). This "triple G" approach produced the highest weight loss ever seen in an anti-obesity clinical trial.
References
- 1Retatrutide, a GIP, GLP-1 and glucagon receptor agonist, for people with type 2 diabetes: a randomised, double-blind, placebo and active-comparator-controlled, parallel-group, phase 2 trial(2023)PubMed ↗
- 2
- 3GIP/GLP-1/glucagon receptor co-agonism for the treatment of obesity and type 2 diabetes(2023)PubMed ↗
- 4Retatrutide phase 2 trial results: efficacy on liver fat reduction in participants with MASLD(2024)PubMed ↗
Last updated: 2026-02-14