Retatrutide FDA Approval Timeline

Last updated: February 2026

Current Status

Retatrutide is not FDA approved. It cannot be legally prescribed or purchased outside of clinical trials. There is no brand name, no NDA filing, and no confirmed approval date.

Eli Lilly's Phase 3 trial program (TRIUMPH) is underway. The first Phase 3 results were reported in December 2025, with seven more readouts expected throughout 2026.

Timeline at a Glance

Below is a summary of where retatrutide stands in the FDA approval process. Items are marked as confirmed (based on published data or official announcements) or projected (based on analyst estimates and typical regulatory timelines).

Confirmed Milestones

Projected Milestones

Important: Unless noted as "confirmed," the dates below are analyst projections based on Lilly's public statements and typical regulatory timelines. Actual timelines may differ.

What Has Happened So Far

Phase 1 (2019-2022)

Retatrutide entered first-in-human studies between 2019 and 2020. Results from these early safety and dose-finding studies were published in The Lancet in 2022, demonstrating that the triple agonist mechanism (GIP, GLP-1, and glucagon receptors) was tolerable in humans and showing promising early weight loss signals.

Phase 2 (2022-2023)

Phase 2 trial results generated significant attention in the medical community:

• Obesity trial results were published in the New England Journal of Medicine in 2023, showing weight loss of up to 24.2% at the highest dose over 48 weeks.
• Type 2 diabetes trial results were published in The Lancet in 2023, showing meaningful improvements in blood sugar control alongside substantial weight loss.

These results were widely covered in medical media and prompted Eli Lilly to advance retatrutide into a large-scale Phase 3 program.

Phase 3: The TRIUMPH Program (2023-present)

Eli Lilly launched the TRIUMPH clinical trial program in 2023. This is a series of Phase 3 trials studying retatrutide across multiple conditions:

• TRIUMPH-1: Obesity (basket trial with nested OSA and OA protocols)
• TRIUMPH-2: Obesity in type 2 diabetes population (with nested OSA)
• TRIUMPH-3: Weight management in cardiovascular disease population
• TRIUMPH-4: Obesity with knee osteoarthritis (completed — results December 2025)
• Additional trials covering MASLD (metabolic dysfunction-associated steatotic liver disease), cardiovascular/renal outcomes, chronic low back pain, and weight maintenance
• TRANSCEND program: Dedicated type 2 diabetes trials (separate from TRIUMPH)

TRIUMPH-4 was the first Phase 3 trial to report results, announced in December 2025. It met its primary endpoints, showing an average weight loss of 28.7% in participants with obesity and knee osteoarthritis. This was widely viewed as a positive signal for the broader program.

For detailed trial-by-trial tracking, see our Clinical Trials & Results page.

What to Watch in 2026

Seven Phase 3 readouts are expected throughout 2026. These are the data releases that will determine whether and when Eli Lilly files for FDA approval.

Key trials to watch:

• TRIUMPH-1 and TRIUMPH-2 (obesity): These are the most important trials for the likely first FDA submission. If results are strong, they form the foundation for an obesity indication NDA.
• TRIUMPH-3 (type 2 diabetes): Could support a simultaneous or near-simultaneous diabetes filing.
• Remaining TRIUMPH trials: Results in sleep apnea, MASLD, and other conditions will determine additional indication filings later.

Each readout will be covered on our News page as results are announced.

How the FDA Approval Process Works

For readers unfamiliar with FDA drug approval, here is how the remaining steps typically unfold:

Step 1: Phase 3 Trial Completion

The drug maker completes large-scale trials demonstrating safety and efficacy. Retatrutide is currently in this stage. Eli Lilly needs sufficient data from the TRIUMPH program before filing.

Step 2: NDA Submission

Eli Lilly compiles all clinical data into a New Drug Application (NDA) and submits it to the FDA. The FDA then has 60 days to decide whether to accept the application for review (called the "filing decision").

Projected for retatrutide: 2026 (confirmed by Lilly on Q4 2025 earnings call, February 4, 2026).

Step 3: FDA Review

Once the NDA is accepted, the FDA assigns a Prescription Drug User Fee Act (PDUFA) target date. This is the deadline by which the FDA aims to complete its review.

• Standard review: 10 months from NDA acceptance
• Priority review: 6 months from NDA acceptance (granted for drugs offering significant improvements over existing treatments)

Retatrutide has no publicly announced Fast Track designation, Breakthrough Therapy designation, or other expedited pathway. A standard 10-month review is the baseline assumption, though the FDA could grant priority review given the drug's novel mechanism.

Step 4: Advisory Committee Meeting (Possible)

The FDA may convene an advisory committee of outside experts to review the data and vote on whether the drug should be approved. This step is not required for every drug.

Step 5: FDA Decision

The FDA issues one of three decisions:

• Approval — The drug can be marketed and prescribed
• Complete Response Letter (CRL) — The FDA identifies issues that must be resolved before approval
• Refuse to File — The application is incomplete (rare at this stage)

How Retatrutide Compares to Similar Drug Approvals

Eli Lilly and Novo Nordisk have recently brought several GLP-1 receptor agonist drugs through the FDA process. These timelines provide context for what to expect with retatrutide:

Zepbound and Wegovy both received relatively fast reviews for obesity indications. If retatrutide follows a similar pattern, approval could come within 6-12 months of NDA filing, rather than the full 10-month standard timeline.

However, retatrutide is a first-in-class triple agonist (targeting GIP, GLP-1, and glucagon receptors simultaneously), which may lead to more cautious FDA review compared to drugs with established mechanisms.

Which Indications Will Be Filed First?

Eli Lilly is studying retatrutide across a broad range of conditions. Based on the TRIUMPH program structure and Lilly's track record with tirzepatide, the most likely filing sequence is:

1. Obesity — Expected to be the first indication filed, supported by TRIUMPH-1 and TRIUMPH-2 data
2. Type 2 diabetes — May be filed simultaneously or shortly after, supported by TRIUMPH-3 data
3. Additional indications — Knee osteoarthritis, sleep apnea, MASLD, cardiovascular outcomes, and chronic low back pain would follow based on their respective trial timelines

This mirrors how Lilly handled tirzepatide: Mounjaro was approved for diabetes first (May 2022), followed by Zepbound for obesity (November 2023).

Brand Name

Eli Lilly has not announced a brand name for retatrutide. The drug is currently referred to only by its generic name.

Based on Lilly's precedent with tirzepatide, retatrutide will likely receive separate brand names for different indications:

• Tirzepatide became Mounjaro for type 2 diabetes and Zepbound for obesity
• Retatrutide is expected to follow the same pattern with distinct brand names per indication

Brand names are typically announced closer to the FDA approval date or during the NDA review period.

What Happens After FDA Approval

Even after FDA approval, there are several steps before retatrutide becomes widely available:

Prescriptions and Availability

• Lilly will need to scale manufacturing, which typically begins well before approval
• Initial supply may be limited, similar to the early availability challenges seen with Mounjaro and Zepbound
• Prescriptions will initially require an in-person or telehealth consultation with a licensed provider

Insurance Coverage

• Insurance coverage is not automatic upon FDA approval
• Private insurers will set their own coverage policies, which can take months to finalize
• Medicare and Medicaid coverage depends on the approved indication and ongoing policy decisions
• The Medicare Inflation Reduction Act drug price negotiation program may eventually apply

Pricing Context

Current GLP-1 drug pricing provides context for what retatrutide might cost, though Lilly has not announced pricing:

GoodRx has offered introductory pricing of $199/month for certain GLP-1 medications. Pricing trends across the GLP-1 class have been downward due to competition and government negotiation.

For ongoing pricing updates, see our Cost & Access page.

Frequently Asked Questions

Sources

• Eli Lilly Q4 2025 earnings call transcript (February 4, 2026) — confirmed regulatory submission planned for 2026
• Eli Lilly press releases and investor communications
• ClinicalTrials.gov (TRIUMPH program trial registrations)
• Jastreboff AM, et al. New England Journal of Medicine (2023) — Phase 2 obesity results
• Rosenstock J, et al. The Lancet (2023) — Phase 2 type 2 diabetes results
• Frias JP, et al. The Lancet (2022) — Phase 1 results
• FDA.gov — Drug approval process and PDUFA guidelines

Related Pages

• What Is Retatrutide (GLP-3)? — How the triple agonist works
• Clinical Trials & Results — Detailed TRIUMPH program tracker
• Retatrutide vs Mounjaro — Side-by-side comparison
• Side Effects & Safety — What clinical trials have shown
• Cost & Access — Pricing, insurance, and how to get it
• News & Updates — Chronological tracker of every development

This page is updated as new information becomes available. Bookmark it to stay current on retatrutide's path to FDA approval.

Medical disclaimer: The information on this page is for educational purposes only and is not medical advice. Retatrutide is an investigational drug that has not been approved by the FDA. Do not attempt to obtain or use retatrutide outside of supervised clinical trials. Always consult a qualified healthcare provider before making decisions about medications or weight management. glp3.wiki is not affiliated with Eli Lilly or any pharmaceutical company.