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AMIRAVOResearch Library
Cycle-length evidence

Retatrutide cycle length: what human studies ran

InvestigationalAHuman trial evidence
Short answer: there is no established Retatrutide cycle length or break. The human studies below ran for set periods under monitoring; none tested repeated courses.

Treatment and follow-up in human studies

  1. Phase 1b: 12 weeks of once-weekly dosing 14. Phase 2 obesity trial: 48 weeks, primary endpoint at 24 weeks 1. Phase 2 type 2 diabetes trial: primary endpoint at 24 weeks with secondary endpoints at 36 weeks 2.
  2. TRIUMPH-1 and TRIUMPH-2: 80 weeks of treatment; the TRIUMPH-1 registry also lists an optional 24-week retatrutide extension with a body-weight endpoint at week 104 3,4,8.
  3. TRANSCEND-T2D-1: 40 weeks 5. The TRIUMPH-3 registry lists a week-80 primary endpoint (1,946 enrolled) and the TRIUMPH-4 registry a week-68 primary endpoint (445 enrolled) 10,12.

What has not been tested

  • On-and-off schedules or breaks between courses.
  • Repeated courses and long-term exposure beyond the periods listed.
  • Retatrutide combined with other compounds, unless a study above says so.

Frequently asked questions

Is there an established Retatrutide cycle length?
No. Human studies administered Retatrutide for the periods listed on this page. Those are study durations; none tested an on-and-off schedule or a break.
What is the longest human study of Retatrutide?
The durations are listed on this page with their sources; compare them directly rather than relying on a summary.
Do study durations tell me how long to use something?
No. A study duration is how long investigators administered a compound to selected participants under monitoring. It is not a recommended course, and a break between courses has not been tested for any compound on this site that is not approved.
Retatrutide dosing reference Full research page

References

  1. Triple-Hormone-Receptor Agonist Retatrutide for Obesity: A Phase 2 Trial N Engl J Med. 2023
  2. Retatrutide, a GIP, GLP-1 and glucagon receptor agonist, for people with type 2 diabetes: a randomised, double-blind, placebo and active-controlled, parallel-group, phase 2 trial conducted in the USA Lancet. 2023
  3. Retatrutide, a Triple Hormone Receptor Agonist, for Treatment of Obesity (TRIUMPH-1) N Engl J Med. 2026
  4. Retatrutide in adults with obesity and type 2 diabetes (TRIUMPH-2): a double-blind, parallel-group, randomised, placebo-controlled, phase 3 trial Lancet. 2026
  5. Efficacy and safety of retatrutide in people with type 2 diabetes and inadequate glycaemic control with diet and exercise (TRANSCEND-T2D-1): a double-blind, randomised, phase 3 trial Lancet. 2026
  6. LY3437943, a novel triple glucagon, GIP, and GLP-1 receptor agonist for glycemic control and weight loss: From discovery to clinical proof of concept Cell Metab. 2022
  7. A Study of LY3437943 in Participants Who Have Obesity or Are Overweight (NCT04881760), registry record with posted results ClinicalTrials.gov. 2023
  8. A Study of Retatrutide (LY3437943) in Participants Who Have Obesity or Overweight (TRIUMPH-1, NCT05929066) ClinicalTrials.gov. 2026
  9. A Study of Retatrutide (LY3437943) in Participants With Type 2 Diabetes Mellitus Who Have Obesity or Overweight (TRIUMPH-2, NCT05929079) ClinicalTrials.gov. 2026
  10. A Study of Retatrutide (LY3437943) in Participants With Obesity and Cardiovascular Disease (TRIUMPH-3, NCT05882045) ClinicalTrials.gov. 2026
  11. Effect of Retatrutide Compared With Placebo in Adult Participants With Type 2 Diabetes and Inadequate Glycemic Control With Diet and Exercise Alone (TRANSCEND-T2D-1, NCT06354660) ClinicalTrials.gov. 2026
  12. A Study of Retatrutide (LY3437943) Once Weekly in Participants Who Have Obesity or Overweight and Osteoarthritis of the Knee (TRIUMPH-4, NCT05931367) ClinicalTrials.gov. 2026
  13. International Standard Prohibited List 2026 WADA Prohibited List. 2026
  14. 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 Lancet. 2022
  15. Retatrutide Once Weekly for Treatment of Obstructive Sleep Apnea N Engl J Med. 2026
  16. A Study of LY3437943 in Participants With Type 2 Diabetes (registry record and posted study protocol J1I-MC-GZBD, section 6.1) ClinicalTrials.gov. 2023