Retatrutide is a new medication in development from Eli Lilly — the same company that makes Mounjaro. It uses three hormones instead of two.
Quick Comparison
| Mounjaro | Retatrutide | |
|---|---|---|
| Active drug | Tirzepatide | Retatrutide |
| Drug class | Dual GIP/GLP-1 agonist | Triple GIP/GLP-1/Glucagon agonist |
| FDA approval | Type 2 diabetes (approved) | In clinical trials |
| Dosing | Once weekly | Once weekly (in trials) |
| Status | Available now | Not yet FDA-approved |
What Is Retatrutide?
Retatrutide mimics three hormones:
- GLP-1 — signals fullness, slows digestion
- GIP — works with GLP-1 to boost the effect
- Glucagon — increases energy expenditure (burns more calories)
Mounjaro uses the first two. Retatrutide adds the third.
Weight Loss Results
From clinical trials:
- Mounjaro: ~15-22% body weight loss at max dose
- Retatrutide (in trials): ~24% body weight loss at highest dose
Retatrutide has shown the strongest weight loss results of any GLP-1-type drug so far. The added glucagon component appears to boost calorie burning.
Side Effects
Based on trial data, Retatrutide causes similar side effects:
- Nausea
- Decreased appetite
- Increased heart rate (from the glucagon component)
- Diarrhea or constipation
The glucagon component may cause a slightly higher heart rate, which is being monitored in trials.
Availability
Retatrutide is not yet FDA-approved. Eli Lilly is running Phase 3 trials. If approved, it would likely launch as a weight loss medication.
Cost
No pricing yet. It will likely be priced similarly to Mounjaro/Zepbound (~$1,060/month).
Who Might Benefit?
- People who plateau on tirzepatide
- People who want the strongest possible weight loss
- People who respond well to Eli Lilly medications
Bottom Line
Retatrutide could offer even stronger weight loss than Mounjaro by adding a third hormone that burns more calories. It's not available yet, but it represents the next wave of weight loss medications.
If Mounjaro is working for you now, there's no reason to wait. If you're not getting the results you want, talk to your doctor about current options.
Work with your healthcare provider to determine which medication is right for you. Individual results and experiences vary.