The drug everyone in obesity medicine is talking about. Retatrutide hit 28.7% average weight loss in Phase 3. The highest number ever recorded in any weight loss drug trial in history. Nothing has come close.
A weekly injection targeting three hormones. More powerful than anything currently approved. Think of it as the next step beyond Zepbound and Wegovy, targeting one more hormone, and producing meaningfully stronger results.
Every approved GLP-1 drug today, Wegovy, Zepbound, Ozempic, works by targeting one or two hormone receptors in your gut and brain to reduce appetite. Retatrutide targets three: GLP-1, GIP, and glucagon.
That third receptor (glucagon) is what makes it different. While GLP-1 and GIP reduce how much you want to eat, glucagon receptor activation directly increases how many calories your body burns, even at rest. The result is an attack on obesity from both sides at once: less calories in, more calories out.
Zepbound (tirzepatide) hits GLP-1 and GIP and already outperforms Wegovy. Retatrutide adds that third target, which may explain why Phase 2 results surpassed everything before it.
Three receptors targeted. Attacks hunger and metabolism simultaneously. Each receptor does something different. Together, they produce results no single target drug has matched.
A small subcutaneous injection once a week, similar to Zepbound or Wegovy. The dose is gradually increased over several months to reduce side effects.
GLP-1 and GIP receptor activation reduces hunger hormones and slows gastric emptying. Most trial participants reported dramatically less interest in food within the first few weeks.
The glucagon component increases your resting metabolic rate. Your body burns more energy throughout the day, accelerating fat loss even when you're not active.
Phase 3 TRIUMPH-4: 28.7% weight loss at 68 weeks. Phase 2 (TRIUMPH-1): 24.2% at 48 weeks. Retatrutide has delivered record results at both Phase 2 and Phase 3. The TRIUMPH-1 Phase 2 trial (338 adults, 48 weeks, NEJM 2023) showed 24.2%, then Phase 3 TRIUMPH-4 (obesity with knee osteoarthritis, 68 weeks) topped it at 28.7%, the highest ever recorded in any obesity drug trial. Lilly plans to file an NDA in 2026.
To put this in context: Wegovy (semaglutide), currently the best selling weight loss drug in the world, averages around 15% weight loss. Zepbound (tirzepatide), the most effective approved drug, averages around 20-21%. Retatrutide's Phase 3 TRIUMPH-4 result of 28.7% is the highest number ever recorded in any obesity drug trial. It surpassed Phase 2's already record-breaking 24.2%, and exceeded tirzepatide's SURMOUNT-1 result of 22.5%. An NDA submission is expected in 2026.
Phase 3 TRIUMPH-4 showed 28.7% at 68 weeks. NDA filing expected 2026, FDA decision 2027. Every drug has to pass through three phases of testing before the FDA will approve it. Here's exactly where retatrutide sits today.
Phase 3 trials are still enrolling. You'd get the drug at no cost and have close medical supervision throughout.
Search Open Trials →"Phase 2 data is phase 2 data and I try not to get ahead of it. But the retatrutide numbers were in a range I associate with surgery, not medication. That's enough for me to keep a close eye on where this goes."
Bariatric Surgeon · Obesity Medicine
Not available yet. But here's who it's most likely to help when it is. Retatrutide isn't approved yet, so you can't get a prescription today. But based on Phase 2 data and Eli Lilly's expected indication, here's who it looks best suited for, and who should think carefully.
⚕️Always consult your doctor before starting or changing any weight loss treatment.
Retatrutide vs approved drugs and other pipeline meds. Stacking retatrutide against what's currently available and what's coming.
| Drug | Weight Loss | Mechanism | Form | Status |
|---|---|---|---|---|
| 💉Retatrutide You're here | 24% (Ph2) | Triple Agonist | Weekly injection | Phase 3 |
| 💉Zepbound | 21% | Dual Agonist (GLP-1, GIP) | Weekly injection | ✓ Approved |
| 💉CagriSema | 25% (Ph3) | GLP-1 + Amylin | Weekly injection | Phase 3 |
| 💉Wegovy | 15% | GLP-1 Agonist | Weekly injection | ✓ Approved |
Phase 2 and Phase 3 numbers are from clinical trials, not direct drug to drug comparisons. Interpret any cross trial numbers carefully.