Retatrutide is a new medication in development from Eli Lilly — the same company that makes Zepbound. It uses three hormones instead of two.
Quick Comparison
| Zepbound | Retatrutide | |
|---|---|---|
| Active drug | Tirzepatide | Retatrutide |
| Drug class | Dual GIP/GLP-1 agonist | Triple GIP/GLP-1/Glucagon agonist |
| FDA approval | Weight management (approved) | In clinical trials |
| Dosing | Once weekly | Once weekly (in trials) |
| Status | Available now | Not yet FDA-approved |
What Makes Retatrutide Different?
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)
Zepbound uses the first two. Retatrutide adds the third.
Weight Loss Results
From clinical trials:
- Zepbound: ~21% body weight loss at max dose
- Retatrutide (in trials): ~24% body weight loss at highest dose
Retatrutide has shown stronger results. The added glucagon component appears to boost calorie burning on top of the fullness signals.
Side Effects
Based on trial data, Retatrutide causes similar side effects:
- Nausea
- Decreased appetite
- Increased heart rate (from glucagon)
- 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.
Cost
No pricing yet. Likely similar to Zepbound (~$1,060/month).
Bottom Line
Retatrutide could offer stronger weight loss than Zepbound by adding a calorie-burning hormone. It's not available yet, but it's the next step in weight loss medication.
If Zepbound is working for you, stick with it. 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.