Is retatrutide FDA approved? Current status and timeline

No. As of April 2026, retatrutide (LY3437943) is not FDA approved. It is an investigational drug still in Phase 3 clinical trials. Eli Lilly has not submitted a New Drug Application (NDA) to the FDA, and the drug cannot be legally prescribed through standard pharmacy channels.

That said, the clinical data so far has been strong, and the path to approval looks clear. Here is exactly where things stand, what the trial timeline looks like, and when you might actually be able to get a prescription.

Key takeaways

• Retatrutide is not FDA approved and has no submitted NDA as of April 2026
• The first Phase 3 trial (TRIUMPH-4) reported positive results in December 2025, showing 28.7% weight loss at 68 weeks
• Seven additional Phase 3 trials are expected to complete in 2026
• The earliest realistic FDA approval date is late 2027 or early 2028
• Current alternatives like tirzepatide and semaglutide are FDA approved and available now
• Retatrutide is not available through standard pharmacies, though some compounding pharmacies offer it off-label

What is retatrutide?

Retatrutide is a first-in-class triple hormone receptor agonist made by Eli Lilly. It activates three receptors simultaneously: GIP (glucose-dependent insulinotropic polypeptide), GLP-1 (glucagon-like peptide-1), and glucagon [1]. This makes it different from tirzepatide (Mounjaro/Zepbound), which targets only GIP and GLP-1, and from semaglutide (Ozempic/Wegovy), which targets GLP-1 alone.

The addition of glucagon receptor agonism increases energy expenditure and promotes liver fat reduction [2]. In clinical trials, this triple mechanism produced the largest weight reductions seen in any obesity medication to date.

For a deeper look at the drug’s mechanism and what makes it different from existing options, see our full retatrutide guide and the retatrutide vs tirzepatide comparison.

Current trial status: the TRIUMPH program

Eli Lilly is running a large Phase 3 program called TRIUMPH (Trial Investigating Retatrutide’s Use in Metabolic and Hormonal Health). The program includes eight trials across different patient populations [3]:

Trial	Population	Status	Expected results
TRIUMPH-1	Obesity without diabetes	Ongoing	2026
TRIUMPH-2	Type 2 diabetes	Ongoing	2026
TRIUMPH-3	Obesity (additional populations)	Ongoing	2026
TRIUMPH-4	Obesity + knee osteoarthritis	Completed	December 2025
TRIUMPH-5	Retatrutide vs tirzepatide	Ongoing	2026
TRIUMPH (sleep apnea)	Obstructive sleep apnea	Ongoing	2026
TRIUMPH (back pain)	Chronic low back pain	Ongoing	2026
TRIUMPH (CVOT)	Cardiovascular/renal outcomes	Ongoing	2026-2027

The cardiovascular outcomes trial (CVOT) is the longest, and the FDA may not require its completion before approving retatrutide for obesity. The STEP trials for semaglutide, for example, secured obesity approval before their cardiovascular outcomes data was fully in.

TRIUMPH-4 results (December 2025)

The first completed Phase 3 trial enrolled 445 adults with obesity and knee osteoarthritis. At 68 weeks, participants on the 12 mg dose lost an average of 28.7% of their body weight (71.2 lbs from a baseline average of 248.5 lbs) [3]. The 9 mg dose produced 26.4% weight loss.

Beyond weight loss, participants saw large improvements in knee pain, with WOMAC pain scores dropping by 74-76% [3]. More than 1 in 8 patients on retatrutide were completely free from knee pain at the end of the trial. The drug also reduced cardiovascular risk markers including non-HDL cholesterol, triglycerides, and blood pressure.

Side effects were consistent with the GLP-1 drug class: nausea (43%), diarrhea (33%), constipation (25%), and vomiting (21%) at the 12 mg dose [3]. Dysesthesia (tingling sensations) occurred in 21% of patients on 12 mg, which is higher than what is seen with tirzepatide or semaglutide.

Realistic approval timeline

Here is the most likely sequence of events:

2026: Remaining Phase 3 trials report out. Seven trials deliver results, including the direct comparison to tirzepatide (TRIUMPH-5) and the main obesity trial (TRIUMPH-1). These data form the basis of the NDA submission.

Late 2026 to mid 2027: NDA submission. Eli Lilly compiles the data package and submits to the FDA. The submission timing depends on how quickly data from all trials can be analyzed and assembled.

2027-2028: FDA review and decision. The standard FDA review period for an NDA is 10 months from acceptance. Priority review (6 months) is possible if the FDA grants it. Given the unmet need in obesity treatment and the strength of the data, priority review is plausible.

2028: Commercial launch. If everything goes according to plan, retatrutide could be available by prescription in late 2027 or early 2028.

These are estimates, not official timelines from Eli Lilly or the FDA. Manufacturing delays, additional safety data requests, or advisory committee reviews could push the timeline back. Prediction markets currently put the probability of 2026 approval at around 27%, reflecting the consensus that it is unlikely before 2027 [4].

Why the wait matters

The FDA approval process exists for good reason. Phase 3 trials confirm that a drug works in large, diverse populations and that the safety profile is acceptable for widespread use. Phase 2 data is promising but involves smaller patient groups and shorter follow-up.

For retatrutide specifically, several questions still need Phase 3 answers:

• What is the optimal maintenance dose for long-term weight management?
• How does it perform directly against tirzepatide (TRIUMPH-5)?
• What is the risk-benefit profile in patients with type 2 diabetes?
• How does it affect cardiovascular outcomes long-term?
• Is the dysesthesia signal clinically significant at scale?

These are not theoretical concerns. They determine how the drug gets labeled, what patient populations it is approved for, and what monitoring is required after prescribing.

What about compounding pharmacy access?

Some compounding pharmacies have begun offering retatrutide before FDA approval. This is a gray area. Unlike semaglutide, which has an FDA-approved reference drug and established compounding pathways, retatrutide has no approved reference product. This means compounding pharmacies are sourcing raw material without the same regulatory framework that applies to compounded semaglutide or tirzepatide.

If you pursue compounding access, work with a 503B outsourcing facility that conducts third-party potency and purity testing. Understand that you are using an unapproved drug through an unregulated pathway, and factor that risk into your decision.

For the full breakdown of access options, see our guide on how to get retatrutide.

FDA-approved alternatives available today

You do not have to wait for retatrutide to start effective weight loss treatment. Several medications are approved and available right now:

Tirzepatide (Mounjaro/Zepbound)

The closest option to retatrutide. Tirzepatide targets GIP and GLP-1 (two of retatrutide’s three targets) and has shown weight loss of up to 22.5% in the SURMOUNT-1 trial [5]. It is FDA-approved for both type 2 diabetes and obesity. You can start with a tirzepatide online prescription through telehealth.

Semaglutide (Ozempic/Wegovy)

The most widely used GLP-1 medication. Semaglutide produces approximately 15% weight loss at the 2.4 mg dose [6]. It is available at brand pricing or through compounding pharmacies at lower cost. Get started with a semaglutide online prescription.

Other options

For broader information on peptides for weight loss and how different medications compare, our pillar guide covers every available option including emerging treatments.

What indications might retatrutide be approved for?

Based on the TRIUMPH trial program, Eli Lilly is building a case for multiple indications:

• Chronic weight management in adults with obesity (BMI 30+) or overweight (BMI 27+) with at least one weight-related condition
• Type 2 diabetes
• Obesity with knee osteoarthritis (the first completed Phase 3 trial specifically targeted this population)
• Obstructive sleep apnea related to obesity
• Metabolic dysfunction-associated steatotic liver disease (MASLD)

The first approved indication will likely be obesity or type 2 diabetes, since those are the most commercially significant. Additional indications may follow as supplemental NDAs based on the disease-specific trials.

For comparison, tirzepatide was first approved for type 2 diabetes (as Mounjaro in 2022), then for obesity (as Zepbound in 2023). Retatrutide could follow a similar two-step path or pursue both indications simultaneously.

How the Phase 2 data built the case

The Phase 2 trial, published in the New England Journal of Medicine in 2023, enrolled 338 adults with obesity and tested multiple doses over 48 weeks [7]. The results were striking:

• 1 mg dose: 8.7% weight loss
• 4 mg dose: 17.1% weight loss
• 8 mg dose: 22.8% weight loss
• 12 mg dose: 24.2% weight loss (57.8 lbs average)
• Placebo: 2.1% weight loss

At the 12 mg dose, 100% of participants achieved at least 5% weight loss, and 26% lost more than 30% of body weight. These numbers exceeded anything previously reported for a weight loss medication in a controlled trial and made the case for the large Phase 3 program that followed.

Regulatory context: the FDA and weight loss drugs

Retatrutide sits within a period of rapid FDA activity around weight loss medications. In 2022, tirzepatide was approved for diabetes. In 2023, it was approved for obesity. The FDA’s approach to peptide regulation has also shifted, with reclassification of certain peptides in early 2026.

The GLP-1 drug class has proven safety and efficacy across multiple large trials, which may help retatrutide’s review. The FDA is increasingly comfortable with this mechanism of action. But each new drug still needs to prove itself independently through its own trial program.

Frequently asked questions

When will retatrutide be FDA approved?▼

The most likely timeline is late 2027 or early 2028. This assumes Eli Lilly completes Phase 3 trials in 2026, submits an NDA by mid 2027, and receives a standard or priority review decision within 6 to 10 months.

Is retatrutide the same as tirzepatide?▼

No. Both are made by Eli Lilly and are once-weekly injectable medications, but they target different receptors. Tirzepatide activates GIP and GLP-1 receptors (dual agonist). Retatrutide activates GIP, GLP-1, and glucagon receptors (triple agonist). See our retatrutide vs tirzepatide comparison for a detailed breakdown.

Can I get retatrutide right now?▼

The main options are clinical trial enrollment and some compounding pharmacies. Standard prescriptions are not available because retatrutide is not FDA-approved. For all current access pathways, see how to get retatrutide.

Is retatrutide safe?▼

Phase 2 and Phase 3 trial data show a safety profile consistent with other GLP-1 class medications. The most common side effects are gastrointestinal (nausea, diarrhea, vomiting). Dysesthesia (tingling sensations) occurred more frequently with retatrutide than with other drugs in this class. Long-term safety data will become available as Phase 3 trials complete.

How much weight can you lose on retatrutide?▼

In the Phase 3 TRIUMPH-4 trial, participants on the 12 mg dose lost an average of 28.7% of body weight (71.2 lbs) over 68 weeks [3]. Phase 2 showed 24.2% weight loss at 48 weeks [7]. Individual results vary based on dose, starting weight, diet, and exercise.

Will my insurance cover retatrutide when it is approved?▼

That will depend on the approved indications and your specific plan. If approved for obesity, coverage patterns will likely follow those of tirzepatide and semaglutide. Insurance coverage for weight loss medications has been expanding but remains inconsistent. See our guide on insurance and peptide therapy.

What is the TRIUMPH program?▼

TRIUMPH stands for Trial Investigating Retatrutide’s Use in Metabolic and Hormonal Health. It is Eli Lilly’s Phase 3 clinical trial program for retatrutide, consisting of at least eight trials testing the drug in obesity, type 2 diabetes, knee osteoarthritis, sleep apnea, back pain, liver disease, and cardiovascular outcomes.

Want to start effective weight loss treatment today? See if you qualify for tirzepatide or semaglutide through our online evaluation. FDA-approved options are available now while we wait for next-generation treatments like retatrutide.

References

1. Coskun T, Urva S, Roell WC, et al. LY3437943, a novel triple glucagon, GIP, and GLP-1 receptor agonist for glycemic control and weight loss. Cell Metab. 2022;34(9):1234-1247.
2. Sanyal AJ, Kaplan LM, Frias JP, et al. Triple hormone receptor agonist retatrutide for metabolic dysfunction-associated steatotic liver disease: a randomized phase 2a trial. Nat Med. 2024;30:2037-2048.
3. Eli Lilly. Lilly’s triple agonist, retatrutide, delivered weight loss of up to an average of 71.2 lbs along with substantial relief from osteoarthritis pain in first successful Phase 3 trial. Press release. December 11, 2025.
4. Lines.com. FDA Retatrutide Approval 2026 prediction market. Accessed April 2026.
5. Jastreboff AM, Aronne LJ, Ahmad NN, et al. Tirzepatide once weekly for the treatment of obesity (SURMOUNT-1). N Engl J Med. 2022;387(3):205-216. doi:10.1056/NEJMoa2206038
6. Wilding JPH, Batterham RL, Calanna S, et al. Once-weekly semaglutide in adults with overweight or obesity. N Engl J Med. 2021;384(11):989-1002.
7. Jastreboff AM, Kaplan LM, Frías JP, et al. Triple-hormone-receptor agonist retatrutide for obesity — a phase 2 trial. N Engl J Med. 2023;389(6):514-526.