Retatrutide is an investigational triple agonist that simultaneously targets GLP-1, GIP, and glucagon receptors — currently in Phase 3 clinical trials and projected for FDA review in late 2026 with potential approval in 2027 or 2028. At My Concierge MD, Dr. David Nazarian — a board-certified internal medicine physician trained at UCLA, the Sackler School of Medicine, and Huntington Memorial Hospital, a USC-affiliated teaching institution — provides clinical consultation regarding retatrutide and other emerging weight loss therapies within a comprehensive medical weight loss program in Beverly Hills.
Initially found Dr Nazarian for medical weight loss and then found out about all the regenerative and anti aging medicine services his medical clinic offers. They have one of the best IV exosomes and exosome therapy available. They have been able to help me overcome my fatigue as welll as lose weight safely and effectively. Their semaglutide injections for weight loss has really helped me lose weight and feel so much better.
The Science Behind Retatrutide
Retatrutide is a once-weekly subcutaneous injection developed by Eli Lilly that engages three hormonal pathways central to appetite regulation, metabolism, and energy balance:
- GLP-1 (Glucagon-Like Peptide-1): Reduces appetite, slows gastric emptying, and improves glycemic control.
- GIP (Glucose-Dependent Insulinotropic Polypeptide): Enhances insulin sensitivity and complements GLP-1 in modulating food intake.
- Glucagon Receptor: Increases energy expenditure and influences hepatic fat metabolism.
This triple-receptor mechanism distinguishes retatrutide from semaglutide (a single agonist, GLP-1 only) and from tirzepatide (a dual agonist, GLP-1 and GIP), and represents the most pharmacologically complex GLP-class medication currently in late-stage clinical development.
Clinical Research and Outcomes
In Phase 2 trials, retatrutide produced an average weight loss of approximately 24 percent of body weight at the highest dose over 48 weeks — the highest weight loss outcome ever reported in a GLP-class medication trial. The Phase 3 TRIUMPH program, ongoing through 2026, is evaluating retatrutide across multiple patient populations:
- TRIUMPH-1: Adults with obesity without diabetes
- TRIUMPH-2: Adults with type 2 diabetes
- TRIUMPH-4: Adults with obesity and knee osteoarthritis
- TRIUMPH CVOT: Cardiovascular outcomes trial
The December 2025 TRIUMPH-4 readout reported an average weight loss of 28.7 percent of body weight at 68 weeks — the highest reported weight loss percentage in any obesity drug trial to date. Final readouts from the remaining Phase 3 studies are expected through 2026.
Current FDA Status
As of 2026, retatrutide is not FDA-approved for any indication and cannot be legally prescribed outside of clinical trials in the United States. Eli Lilly is expected to submit a New Drug Application in late 2026, with potential FDA approval in 2027 or 2028 if Phase 3 data supports the submission.
Patients interested in retatrutide today have two practical pathways:
- Clinical trial participation: Eligible patients may be assessed for enrollment and referred to active TRIUMPH study sites.
- Treatment with FDA-approved alternatives: Many patients begin therapy with currently approved medications such as tirzepatide or semaglutide and plan a clinical transition to retatrutide once it becomes commercially available.
How My Concierge MD Approaches Retatrutide
At My Concierge MD, retatrutide consultations are integrated into a broader medical weight loss evaluation:
- Education and Informed Decision-Making: Each consultation includes a clear discussion of retatrutide’s current FDA status, available clinical evidence, projected timelines, and the limitations of access outside FDA-approved channels.
- Evaluation for FDA-Approved Alternatives: Most patients interested in retatrutide are also candidates for FDA-approved therapies such as tirzepatide or semaglutide, and those options are typically discussed first.
- Clinical Trial Referral When Appropriate: Patients interested in participating in retatrutide research may be evaluated for eligibility and referred to active TRIUMPH study sites.
- Continuity for Future Transition: Patients who begin treatment with FDA-approved GLP-class medications can plan a clinical transition to retatrutide once approval is granted and the medication enters the market.
Frequently Asked Questions About Retatrutide
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Retatrutide activates three hormonal pathways — GLP-1, GIP, and glucagon receptors — while tirzepatide activates two (GLP-1 and GIP) and semaglutide activates only GLP-1. Phase 2 retatrutide trials reported higher average weight loss than published outcomes for either tirzepatide or semaglutide at comparable durations, though direct head-to-head trials have not yet been published. Currently FDA-approved alternatives are typically discussed during a medical weight loss consultation.
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Eli Lilly is expected to submit a New Drug Application to the FDA in late 2026. Under standard FDA review timelines, approval could occur in 2027 or 2028 if Phase 3 trial data supports the submission. The cardiovascular outcomes trial (TRIUMPH CVOT) is expected to continue through 2028 and may influence labeling decisions, though it is not expected to delay initial approval.
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Retatrutide cannot be legally prescribed outside of FDA-approved clinical trials in the United States as of 2026. Patients seeking access have two pathways: enrollment in active Phase 3 TRIUMPH clinical trial sites, or beginning treatment with an FDA-approved alternative such as tirzepatide until retatrutide becomes commercially available.
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Phase 2 trials reported an average weight loss of approximately 24 percent of body weight at the highest dose over 48 weeks. The December 2025 TRIUMPH-4 readout reported 28.7 percent body weight loss at 68 weeks — the highest reported weight loss outcome in any obesity drug trial to date. Final Phase 3 data from additional TRIUMPH studies is expected through 2026.
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Most retatrutide side effects mirror those of the broader GLP-class — primarily gastrointestinal symptoms such as nausea, decreased appetite, and gastrointestinal upset. The December 2025 TRIUMPH-4 data identified a side effect not seen with prior GLP medications: dysesthesia, a sensation of skin tingling or tenderness reported by approximately 20.9 percent of patients on the highest dose. The clinical significance of this finding is still being characterized.
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A consultation with Dr. Nazarian can clarify your options, including whether you’re a candidate for currently FDA-approved therapies, eligibility for clinical trial participation, and how to plan a future transition to retatrutide once it becomes available. Most patients elect to begin treatment with an FDA-approved medication now and reassess once retatrutide enters the market.
Why Choose My Concierge MD for Retatrutide Consultation
- Physician-Led Evaluation: Consultations are conducted by Dr. David Nazarian, a board-certified internal medicine physician trained at UCLA, the Sackler School of Medicine, and Huntington Memorial Hospital — a USC-affiliated teaching institution — and a diplomate of the American Board of Internal Medicine.
- Honest Regulatory Framing: Each consultation includes a clear discussion of retatrutide’s current FDA status, available alternatives, and realistic timeline for U.S. approval rather than oversimplified marketing claims.
- Integrated Treatment Planning: Retatrutide consultations are positioned within a comprehensive medical weight loss program, allowing patients to begin treatment with FDA-approved medications now and plan transitions as new therapies become available.
- Continuity Across the GLP Class: The practice maintains active treatment protocols for semaglutide and tirzepatide, allowing seamless management as the GLP-class medication landscape evolves.
Schedule a Retatrutide Consultation in Beverly Hills
Schedule a consultation with Dr. Nazarian at My Concierge MD in Beverly Hills to discuss retatrutide, currently FDA-approved alternatives, and how to develop a medical weight loss strategy aligned with both your goals and the evolving therapeutic landscape. Each evaluation is conducted with the time, depth, and direct physician access that defines the concierge medicine model — serving patients across Beverly Hills and Greater Los Angeles.