When will retatrutide be available?
Quick read · 5 min
Retatrutide is Eli Lilly's investigational triple-agonist weight loss drug. It is not yet FDA approved. The first Phase 3 trial (TRIUMPH-4) published results in 2026 showing 28.7% average weight loss at 68 weeks. Based on the Phase 3 programme timeline, a possible FDA decision in 2027 has been estimated by analysts, but this is not confirmed.
This treatment is in clinical trials and has not been approved by the FDA or any regulatory authority. It is not available for prescription.
- •Retatrutide is not yet FDA approved and cannot be prescribed
- •First Phase 3 result (TRIUMPH-4, 2026): 28.7% weight loss at 68 weeks — highest ever in a Phase 3 trial
- •FDA approval timeline estimated 2027, but not confirmed by Eli Lilly
- •Remaining Phase 3 trials (TRIUMPH-1, -2, -3) expected to report in 2026
- •Only way to access it now is by enrolling in an active clinical trial
- •Price and insurance coverage unknown until approval
Based on clinical trials · No rankings · Every claim linked to source
Current status (April 2026)
Development stage
Phase 3 (TRIUMPH programme)
TRIUMPH-4 published; TRIUMPH-1, -2, -3 data expected 2026
FDA submission
Not yet filed
Eli Lilly has not announced a New Drug Application (NDA) date
Estimated approval
2027 (analyst estimate)
Not confirmed by Eli Lilly. Actual timing depends on Phase 3 completion and FDA review.
How to access now
Clinical trial enrollment only
Not available by prescription or pharmacy
Retatrutide development timeline
Here's where retatrutide is in the drug approval process and what has to happen before it reaches pharmacies.
2023
Phase 2 results published
338 adults with obesity. Up to 24.2% weight loss at 48 weeks with 12mg weekly dose. Results published in New England Journal of Medicine. This prompted the full Phase 3 programme.
2026 (published)
TRIUMPH-4 Phase 3 results
Adults with obesity and knee osteoarthritis. 28.7% average weight loss at 68 weeks — the highest ever recorded in a Phase 3 trial for any weight loss drug. 75.8% reduction in knee pain alongside weight loss.
Expected 2026
TRIUMPH-1, -2, -3 data
TRIUMPH-1: adults with obesity, no diabetes. TRIUMPH-2: adults with obesity + type 2 diabetes. TRIUMPH-3: adults with Class II/III obesity and established cardiovascular disease. Collective data needed for FDA filing.
Not yet scheduled
FDA New Drug Application (NDA) filed
Eli Lilly has not announced a submission date. Submission usually follows completion of the Phase 3 programme.
Estimated 2027
FDA review and possible approval
Standard FDA review is 10 months; priority review is 6 months. Approval is not guaranteed — the FDA may request additional data.
Post-approval
Commercial launch
Manufacturing, pharmacy distribution, insurance negotiations, and price announcement typically follow FDA approval by 2–6 months.
A note on timing estimates: Drug development timelines routinely slip. Phase 3 trials can be delayed by enrollment challenges, safety signals, or regulatory questions. Any date mentioned before an official FDA approval is an estimate, not a guarantee.
Why people are watching retatrutide
Retatrutide targets three hormone receptors at once — GLP-1, GIP, and glucagon. The addition of glucagon receptor activation is the key difference from currently approved drugs.
GLP-1 (reduces appetite): The same signal that semaglutide activates. Slows stomach emptying and reduces hunger.
GIP (enhances appetite reduction): The second signal that tirzepatide activates alongside GLP-1. Produces additional weight loss beyond GLP-1 alone.
Glucagon (increases metabolic rate): The third signal, new to retatrutide. May increase how many calories your body burns at rest, adding to the appetite effect from the other two.
In Phase 2, this triple mechanism produced 24.2% average weight loss at 48 weeks. TRIUMPH-4 Phase 3 pushed this to 28.7% at 68 weeks — and weight had not yet plateaued by the end of the study, suggesting more loss may be possible with longer treatment.
How to access retatrutide today
The only legitimate way to take retatrutide today is by enrolling in an active clinical trial. Here's what that involves:
1. Search clinicaltrials.gov
Visit clinicaltrials.gov and search for "retatrutide" or specific trial names (TRIUMPH-1, TRIUMPH-2, TRIUMPH-3). Filter by trial status "recruiting" and your location to find nearby sites.
2. Check eligibility requirements
Trials usually require a BMI above a specific threshold (often 27+ or 30+). They may exclude people with certain health conditions, recent weight loss surgery, or current use of other GLP-1 medications. Full criteria are listed on each trial's clinicaltrials.gov page.
3. Contact trial sites directly
Each trial site lists a contact phone or email. Call to express interest and ask about current enrollment status — trials can fill up and close to new participants without warning.
4. Understand the randomisation
Clinical trials are randomised — you may be assigned to placebo (no active drug) or a lower dose. Not everyone in the trial receives the full treatment. Some trials offer all participants active drug after a placebo-controlled phase.
A warning about compounded retatrutide: Some compounding pharmacies advertise "retatrutide" for sale. These products are not FDA approved, not verified to contain the same molecule as Eli Lilly's investigational drug, and may be unsafe. Eli Lilly has warned publicly that compounded versions are not authorised. Avoid these products.
What to do while waiting
If you're interested in retatrutide but it's not yet available, here are some things you can do now:
- •Consider currently approved options. Tirzepatide (20.9% in SURMOUNT-1) and semaglutide (14.9% in STEP 1) are already FDA approved and available. Weight lost now can be meaningful even if retatrutide later offers more.
- •Track the TRIUMPH programme. Phase 3 results in 2026 will give much clearer picture of safety, discontinuation rates, and comparative weight loss.
- •Talk to an obesity medicine specialist. They often know about enrolling trials in your area and can help you think about whether waiting or starting now makes sense for your situation.
- •Build habits now. Resistance training and protein intake will matter more, not less, if you later start a powerful weight loss drug — they preserve muscle during rapid weight loss.
Related pages
Next step most people take
Based on clinical trials · No rankings · Every claim linked to source
Last reviewed: March 2026