Retatrutide
MED-000027
Retatrutide is an investigational triple hormone receptor agonist (GLP-1, GIP, and glucagon) developed by Eli Lilly. It is not FDA-approved and not available by prescription as of July 2026. Phase 3 trial results have shown up to 28.3% average weight loss at 80 weeks -- among the highest reported for any obesity medication in development -- with an NDA filing expected in late 2026 and potential approval as early as 2027-2028.
Medication Overview
Generic Name:
Medication Class:
Manufacturer:
Route:
Dosing Frequency:
Retatrutide
GLP-1/GIP/Glucagon triple agonist
Eli Lilly (investigational)
Injection
Weekly (investigational)
Status:
Draft
Medication Summary
Retatrutide is an investigational triple hormone receptor agonist (GLP-1, GIP, and glucagon) developed by Eli Lilly. It is not FDA-approved and not available by prescription as of July 2026. Phase 3 trial results have shown up to 28.3% average weight loss at 80 weeks -- among the highest reported for any obesity medication in development -- with an NDA filing expected in late 2026 and potential approval as early as 2027-2028.
Aliases
LY3437943
Search Keywords
retatrutide, triple agonist, retatrutide fda approval, is retatrutide approved, LY3437943
Medication Uses
Part of the DietApp.com GLP-1 Medication Database, a comprehensive, regularly reviewed reference covering every GLP-1-class medication.
Retatrutide is an investigational medication — it is not approved by the FDA, not available by prescription, and not legally available for purchase in the US outside of clinical trial enrollment. Anyone offering retatrutide for sale outside a registered clinical trial is not selling an FDA-regulated, verified product.
Retatrutide is being studied across multiple Phase 3 trials (the TRIUMPH and TRANSCEND-T2D programs) for obesity, type 2 diabetes, obstructive sleep apnea, knee osteoarthritis, cardiovascular and kidney outcomes, and MASLD/MASH. As of mid-2026, three Phase 3 programs have reported positive topline results.
Dosage
Trial dosing has evaluated once-weekly subcutaneous injections up to a 12 mg maintenance dose, with higher doses associated with greater average weight loss in Phase 3 data. There is no approved dosing, since retatrutide has no current FDA-approved use — this information reflects clinical trial protocols only and should not be treated as prescribing guidance.
Administration
In clinical trials, retatrutide is administered as a once-weekly subcutaneous injection. Since there is no FDA-approved product, there are no approved administration instructions, injection site guidance, or patient labeling available outside the clinical trial setting.
Benefits
Clinical trials have shown meaningful results so far:
- TRIUMPH-1 (Phase 3, obesity): 28.3% average weight loss at 80 weeks; patients with BMI ≥35 reached up to 30.3% average weight loss at 104 weeks, with no plateau observed
- TRANSCEND-T2D-1 (Phase 3, type 2 diabetes): up to 2.0% HbA1c reduction and 16.8% weight loss
- A nested substudy also reported a 60.6% reduction in apnea-hypopnea index in patients with obstructive sleep apnea
These are trial results, not guaranteed outcomes, and apply only to study participants under controlled conditions.
Side Effects
Consistent with other GLP-1-class medications, gastrointestinal side effects (nausea, vomiting, diarrhea) have been reported in trials. A notable additional signal identified in Phase 3 data is dysesthesia (an abnormal skin sensation), reported in approximately 20.9% of patients at the highest studied dose — this hasn't been a prominent feature of other approved GLP-1 medications and is being monitored as trials continue.
Warnings
Because retatrutide is not FDA-approved, there is no finalized safety label. Trial data so far suggests a side effect profile broadly similar to other GLP-1-class medications, plus the dysesthesia signal noted above. Full safety information, including any boxed warnings, will be established as part of the FDA review process once an NDA is filed.
Retatrutide sourced outside a registered clinical trial (including from compounding pharmacies or research-chemical sellers) has not been reviewed by the FDA for safety, purity, or accurate dosing, and carries meaningfully different risk than an approved medication.
Drug Interactions
No FDA-reviewed drug interaction data exists yet, since retatrutide is not approved. Like other GLP-1-class and GIP-class medications, it may delay gastric emptying, which could affect absorption of other oral medications — this is being evaluated as part of ongoing clinical trials.
Storage
Storage requirements will be established as part of FDA-approved product labeling if and when retatrutide is approved. No consumer storage guidance currently exists outside the clinical trial setting.
References
- Eli Lilly & Company: TRIUMPH-1 and TRANSCEND-T2D-1 Phase 3 press releases (2026)
- Jastreboff AM, et al. "Triple-Hormone-Receptor Agonist Retatrutide for Obesity." NEJM 2023;389:514-526
- ClinicalTrials.gov: TRIUMPH and TRANSCEND-T2D trial registries
- Drugs.com: Retatrutide approval status
Last medically reviewed and updated: July 11, 2026.
Track Your Progress
Since retatrutide isn't available by prescription yet, there's nothing to log today. If you're currently on an FDA-approved GLP-1 medication, DietApp.com helps you track your dose, nutrition, weight, and symptoms in one place — and we'll update this page the moment retatrutide's regulatory status changes.
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