Retatrutide
medicationLY3437943 · “triple-G”
Investigational metabolic (GLP-1 / GIP / glucagon triple agonist)
Research status · Investigational
Not FDA-approved and not available by prescription. Investigational; in Phase 3 trials (Eli Lilly) as of 2026, with regulatory filing anticipated but not complete.
Retatrutide is an experimental once-weekly injectable being studied for obesity and type 2 diabetes. It is the first triple agonist (acting on GLP-1, GIP, and glucagon receptors) to reach Phase 3. Because it is investigational, it is only legitimately available through clinical trials — products sold elsewhere are unregulated and of unknown identity, purity, and dose.
How it works
Simultaneously activates GLP-1, GIP, and glucagon receptors. GLP-1/GIP activity influences appetite, satiety, and glucose handling; glucagon-receptor activity is thought to increase energy expenditure. Net effect studied: reduced appetite and body weight.
Commonly discussed use cases
- Weight management (investigational)
- Type 2 diabetes / glucose control (investigational)
Supposed / potential benefits
- In trials, substantial average weight reduction over ~48–80 weeks
- Improvements in glucose and metabolic markers reported in study populations
Common side effects
- Nausea, vomiting, diarrhea, constipation (dose-related)
- Reduced appetite beyond comfort
- Injection-site reactions
- Heart-rate changes reported in trials
Warnings & contraindications
- Investigational — long-term safety in the general population is not established
- Products outside a clinical trial are unregulated and potentially unsafe
- As a GLP-class agent, thyroid C-cell tumor signals seen in related drugs are an area of ongoing study
Typical timing considerations
Studied as a once-weekly subcutaneous injection, with gradual dose escalation in trials.
Administration route
Subcutaneous injection
Storage
Investigational; storage would follow trial/manufacturer instructions (typically refrigerated).
Questions to ask your clinician
- Is there a clinical trial I could enroll in rather than sourcing this elsewhere?
- Given it's investigational, what are the unknown risks?
- Are approved GLP-class options more appropriate for my goals?
Commonly tracked in Reta
Tracking fields organize user-entered, clinician-directed routines — Reta never recommends or computes doses.
Track this in Reta
Beta members get a ready-made tracker for Retatrutide — schedule, dose log, injection-site rotation, reminders, and check-ins — for organizing a clinician-directed routine. Personal tracking is available to everyone during the Public Beta.
Reta is a tracking and education tool — not a medical provider. Nothing here is a diagnosis, treatment, prescription, or dosing recommendation. Peptides and medications should only be used under the direction of a licensed clinician. Talk to a qualified clinician before starting, stopping, combining, or changing anything. Many compounds below are not FDA-approved for human use; some are investigational or sold through unregulated channels where purity and dosing are not guaranteed.