Published trial ladder

Retatrutide Phase 3 12 mg arm: published ladder and modeled levels

Updated by the GLP Ladder Editorial Team. Editorial policy.

Short answer

Retatrutide Phase 3 12 mg arm: 2/4/6/9/12 mg weekly, 4 weeks per step (Eli Lilly, May 21, 2026). The final 12 mg step begins in week 17. With t½ 6 days and R = 1.8033, the modeled amount peaks at 19.67 mg-eq. As published, not a recommendation; as of Oct 19, 2026.

Weeks per step
4 5 steps
Final step
12 mg from week 17
Modeled peak
19.67 mg-eq
Accumulation R
1.8033 t½ 6 d
Retatrutide Phase 3 12 mg arm: steps and modeled amountWeekly doses 2 mg, 4 mg, 6 mg, 9 mg, 12 mg; modeled amount peaks at 19.67 mg-equivalents.stable window06.2512.518.7525mg-eq048121620242832weeks from start2 mg4 mg6 mg9 mg12 mg
  • Weekly dose (published steps)
  • Modeled amount (mg-eq)
  • Stable window
Steps start on a Monday (Jan 5, 2026) for illustration. Curve: modeled relative amount, not plasma concentration. Open in the Retatrutide plotter to change dates or doses.
Phase 3 12 mg arm: weeks, weekly dose and dates from a Jan 5, 2026 start (Eli Lilly, May 21, 2026)
WeeksWeekly doseFirst week starts
1–4 2 mg Jan 5, 2026
5–8 4 mg Feb 2, 2026
9–12 6 mg Mar 2, 2026
13–16 9 mg Mar 30, 2026
17 onward 12 mg Apr 27, 2026

Weekly modeled amounts

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32 weeks. Highlighted rows start a new dose step. Model details: model card.

Retatrutide Phase 3 12 mg arm: weekly peak, trough and average (mg-equivalents)
WeekStartsDose mgPeakTroughAverage
1Jan 5, 202621.78201.287
2Jan 12, 202622.6080.9211.945
3Jan 19, 202622.9781.3312.238
4Jan 26, 202623.1441.5142.368
5Feb 2, 202644.9931.5953.713
6Feb 9, 202645.8572.5534.397
7Feb 16, 202646.2442.9794.701
8Feb 23, 202646.4173.1694.837
9Mar 2, 202668.2663.2546.184
10Mar 9, 202669.1344.2126.869
11Mar 16, 202669.5214.6397.174
12Mar 23, 202669.6944.8297.31
13Mar 30, 2026912.434.9149.3
14Apr 6, 2026913.7146.33310.314
15Apr 13, 2026914.2886.96610.766
16Apr 20, 2026914.5447.24710.967
17Apr 27, 20261217.3157.37312.987
18May 4, 20261218.6178.8114.013
19May 11, 20261219.1999.4514.471
20May 18, 20261219.4589.73514.675
21May 25, 20261219.5739.86314.765
22Jun 1, 20261219.6249.91914.806
23Jun 8, 20261219.6479.94414.824
24Jun 15, 20261219.6589.95614.832
25Jun 22, 20261219.6629.96114.835
26Jun 29, 20261219.6649.96314.837
27Jul 6, 20261219.6659.96414.838
28Jul 13, 20261219.6659.96414.838
29Jul 20, 2026—10.3564.6357.119
30Jul 27, 2026—4.6132.0653.171
31Aug 3, 2026—2.0550.921.412
32Aug 10, 2026—0.9150.410.629

Sources

  1. Lilly's triple agonist, retatrutide, delivered powerful weight loss in pivotal Phase 3 obesity trial. Eli Lilly and Company (via PR Newswire; also investor.lilly.com), May 21, 2026. Accessed Oct 19, 2026.
  2. Retatrutide, a Triple Hormone Receptor Agonist, for Treatment of Obesity. N Engl J Med (abstract via PubMed PMID 42814954; doi:10.1056/NEJMoa2604169), Sep 29, 2026. Accessed Oct 19, 2026.
  3. A Study of Retatrutide (LY3437943) in Participants Who Have Obesity or Overweight (TRIUMPH-1). ClinicalTrials.gov (U.S. NLM), Aug 21, 2026. Accessed Oct 19, 2026.
  4. LY3437943, a novel triple GIP, GLP-1, and glucagon receptor agonist in people with type 2 diabetes: a phase 1b, multicentre, double-blind, placebo-controlled, randomised, multiple-ascending dose trial. The Lancet 2022;400(10366):1869-1881 (abstract via PubMed PMID 36354040; doi:10.1016/S0140-6736(22)02033-5), Oct 27, 2022. Accessed Oct 19, 2026.

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