Medication Comparison
Tirzepatide vs Retatrutide
Both are Eli Lilly products. Tirzepatide is available now and highly effective (~22% weight loss). Retatrutide adds a third receptor (glucagon) and early data suggests slightly more weight loss (~24%), but it needs Phase 3 confirmation. Tirzepatide is the best available option today; retatrutide could be the future.
| Category | Tirzepatide | Retatrutide |
|---|---|---|
| Brands | Mounjaro / Zepbound | Not yet approved |
| Class | GLP-1/GIP dual agonist | GLP-1/GIP/Glucagon triple agonist |
| Administration | Weekly injection | Weekly injection |
| Average weight loss | ~22% | ~24% |
| Compounded cost | $150-450/mo (compounded) | Not yet available |
| Brand cost | $1,000-1,200/mo | Not yet available |
| Half-life | ~5 days | ~6 days |
| Dosing frequency | Once weekly | Once weekly |
| Key trial | SURMOUNT-1 (22.5% weight loss) | Phase 2 (up to 24.2% weight loss at 48 weeks) |
Best for Tirzepatide
Patients who need the most effective available medication right now
Best for Retatrutide
Future option — currently in clinical trials, not commercially available
Tirzepatide tradeoffs
Pros
- FDA-approved and available now
- Strong clinical evidence
- Dual mechanism proven effective
Cons
- Dual vs triple receptor
- May be surpassed by next-gen drugs
Retatrutide tradeoffs
Pros
- Triple receptor targeting
- Potentially more weight loss
- May boost energy expenditure via glucagon
Cons
- Not yet available
- Only Phase 2 data
- Unknown pricing and insurance landscape
Common questions
Will retatrutide replace tirzepatide?
It is unlikely to fully replace tirzepatide. They may serve different patient populations. Eli Lilly will likely market both, as they do with Mounjaro and Zepbound today.
How much better is retatrutide than tirzepatide?
Phase 2 data shows retatrutide achieving ~24% weight loss at 48 weeks vs tirzepatide's ~22% at 72 weeks. The additional glucagon component may also improve liver fat and metabolic health.
Should I wait for retatrutide instead of starting tirzepatide?
No. Retatrutide is likely 1-2+ years from approval. If you need treatment now, tirzepatide is an excellent and proven option. You could always switch later if retatrutide proves superior.
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