The Retatrutide File

File: retatrutideCode LY3437943Developer: Eli LillyChecked Nov 12, 2026

Not approvedInvestigational

Retatrutide: where the drug stands today

Retatrutide is not approved anywhere. It is still in phase 3 trials, and Lilly expects to file its FDA application between January and March 2027 [Lilly, Sep 29, 2026].

The six stations from first trial to pharmacy shelf

  1. Completed: Phase 1 Done in 2020 First human doses in 2019; type 2 diabetes study reported in The Lancet [Lancet, 2022]
  2. Completed: Phase 2 Done in 2022 Obesity trial: 24.2% average loss on 12 mg, against 2.1% on placebo, at 48 weeks (NEJM) [NEJM, 2023]
  3. Current stage: Phase 3 Under way Six trials have reported; more are running. Latest readout: Oct 28, 2026 [Lilly, Oct 28, 2026]
  4. Next step, not reached: FDA filing Planned Q1 2027 Lilly plans to submit its application to the FDA [Lilly, Sep 29, 2026]
  5. Not reached: FDA decision No date Comes only after a filing is accepted and reviewed
  6. Not reached: Pharmacies No date No one can legally sell it for human use today [Lilly, Oct 2026]

Start hereThe full first answer

Retatrutide at a glance. One peptide acting on three receptors: GLP-1, GIP and glucagon. Maker: Eli Lilly, code LY3437943. Status: not approved, in phase 3, with 6 phase 3 trials reported. Average weight change at the 12 mg dose versus placebo, from peer-reviewed papers that count everyone assigned, bars to scale: TRIUMPH-1, 80 weeks, 25.0% versus 3.9%; TRIUMPH-4, 68 weeks, 23.7% versus 4.6%; TRIUMPH-2 with type 2 diabetes, 80 weeks, 18.8% versus 5.1%; TRANSCEND-T2D-1 with type 2 diabetes, 40 weeks, 15.3% versus 2.6%. FDA filing planned for Q1 2027; whether it is filed as a drug or a biologic is disputed in court. FDA decision and pharmacies: no date. Basics What is retatrutide? The peptide, the trials and where it stands A once-weekly injected peptide from Eli Lilly that acts on three hormone receptors at once. Six phase 3 trials have reported. No regulator has approved it. Read the guide

Four questionsWhat people ask about retatrutide

What is it?

The molecule, who makes it and how it acts on the body.

Does it work?

Trial results, with the placebo or comparator beside each number.

Is it safe?

Side effects by trial and dose, and what the trials tested.

Can I get it?

Approval timeline, cost and the only legal ways in today.

The guidesEvery guide in the file

What changedThe dated record

  1. Site

    The Retatrutide File launched. Status checked against Lilly releases, ClinicalTrials.gov and the journals: still in phase 3, not approved, FDA filing planned for Q1 2027.

  2. Paper

    NEJM published the knee osteoarthritis results from TRIUMPH-4 and the TRIUMPH-1 knee substudy.

  3. Press release

    Lilly reported topline results from TRANSCEND-T2D-2, the first phase 3 head-to-head trial: retatrutide against semaglutide 2 mg (Ozempic) in type 2 diabetes. Not yet peer reviewed.

  4. Paper

    NEJM published the sleep apnea results from the TRIUMPH-1 and TRIUMPH-2 substudies.

  5. Paper

    TRIUMPH-1 appeared in NEJM and TRIUMPH-2 in The Lancet. Lilly said it plans to submit its application to the FDA in Q1 2027.

  6. Press release

    Lilly reported topline results from TRIUMPH-2 (type 2 diabetes) and TRIUMPH-3 (severe obesity with heart disease).

  7. Press release

    Lilly reported topline results from TRIUMPH-1, the main phase 3 obesity trial.