Retatrutide
Also called Reta
What to know about Retatrutide
Retatrutide is an investigational triple agonist targeting GIP, GLP-1, and glucagon receptors. Trial findings do not establish a self-directed regimen or the quality of online research vials.
- How it may work
- The design combines incretin signalling with glucagon-receptor activity, aiming to affect appetite, glucose regulation, and energy expenditure.
- What research found
- The 2023 phase 2 obesity study randomly assigned 338 adults without diabetes to different treatment groups. Its main weight check was at 24 weeks, with another at 48 weeks. Some groups stayed at one dose; others increased it. There was no single schedule for everyone. The linked study registry tracks later research.
- What is not settled
- Stomach and gut side effects were common, and heart rate rose more at higher doses. Participants were screened and monitored and used study-supplied medicine. Those protections do not establish the safety of an online vial.
- Research and product status
- Retatrutide remains investigational with no licensed U.S. product. FDA states that it cannot be used in compounding under federal law. Discuss licensed alternatives or legitimate clinical trials with a qualified clinician.
Sources
- Phase 2 randomized trial ↗2023 obesity trial: 24-week primary endpoint and 48-week secondary assessment.
- Registered phase 2 obesity trial ↗Exact study arms, population, eligibility, and outcome definitions.
- FDA retatrutide and compounding notice ↗Current U.S. status and concerns about unapproved products.
- ClinicalTrials.gov retatrutide studies ↗Current registered-study status and design records.
Research reference
- Research amount range
- 0.5–12 mg per administration — not a starting amount
- Reference frequency
- Once a week — catalogue input, not a personal schedule
- Evidence route
- Subcutaneous in the cited evidence; formulation matters. Sites and rotation
- Reported timing context
- The cited phase 2 trials used weekly administration under study oversight; they do not establish a personal schedule.
- What people report
- Appetite reports cannot predict an individual's weight outcome. The 2023 obesity trial assessed weight at 24 and 48 weeks.
- Model accumulation timescale
- ~30.0 days — about five half-lives with regular repeated exposure; not time to a result
- Storage
- Storage and in-use limits depend on the exact formulation and packaging. A compound name alone cannot establish temperature, diluent, or shelf life. Details
- Reported course context
- No validated self-directed course
A research and community reference, not medical advice. Figures are descriptive, vary between sources, and are not a recommendation for use.
When results may show
- When change was measured
- The main weight check in the 2023 phase 2 obesity study was at 24 weeks, with another at 48 weeks. These are study check-in times, not a reliable prediction of results in your first week or month.
- When to assess
- Researchers compared groups over months. Some stayed at one dose and others increased it, with medical monitoring throughout. The 24- and 48-week checks do not tell an individual when to increase a dose, continue or stop.
- Conditions and limitations
- The trial included diet and activity counselling. No special injection time or fasting condition was established, and investigational material should not be equated with a future standardized product.
- When to stop
- There is no established personal dose to stay on long term or rule for when to stop. In the trial, the study team used set safety rules. Slow early weight loss is not a reason to raise the dose yourself.
Research timing is descriptive, not a promise or personal instruction. A severe or persistent reaction needs prompt clinical review. This is not medical advice.
Combination evidence and cautions
What is known and unknown about Retatrutide alongside other compounds or medicines.
Key properties
- Formula
- C221H342N46O68
- Mol. weight
- 4,731.33 Da
- CAS
- 2381089-83-2
External references
Approximately six days in the phase 1b study; a model input, not a measured personal level or outcome timeline.
Investigational. The range combines separate phase 2 studies: obesity target arms were 1, 4, 8 and 12 mg; a type 2 diabetes study also included 0.5 mg. Fixed and escalating arms differed. These figures do not define a starting amount or a single escalation plan, so no universal schedule is shown.
Modelled level — once a week
1× is the peak after a single dose.
- Steady-state peak
- 1.74× single dose
- Time to steady state
- 30.0days
- Administrations
- 1/ week
Read off the modelled curve, not an even-interval formula
About five half-lives
Where these numbers come from
- Jastreboff AM et al., NEJM 2023Phase 2 obesity study: 338 adults, separate weekly study arms, primary weight endpoint at 24 weeks and secondary assessment at 48 weeks.
- NCT04881760: registered obesity study armsSeparate fixed and escalating arms using the study product; not a personal regimen or proof of equivalence for commercial vials.
- Rosenstock J et al., Lancet 2023Separate phase 2 type 2 diabetes study, including a fixed 0.5 mg weekly arm.
- Urva S et al., Lancet 2022Phase 1b pharmacokinetics: approximate six-day half-life.