Is Retatrutide FDA Approved? What to Know

No, retatrutide is not FDA approved as of October 2024. This experimental weight loss drug from Eli Lilly is still in phase 3 clinical trials, showing strong results for obesity treatment. While promising data suggests it could rival or surpass drugs like Ozempic and Mounjaro, patients must wait for full approval to ensure safety and legality.

Is Retatrutide FDA Approved? The Short Answer

Retatrutide remains an investigational drug, meaning it cannot be prescribed or sold legally outside of clinical trials. The FDA has not granted approval for any indication, including weight loss or obesity management.

Current FDA Approval Status for Retatrutide

The answer to "is retatrutide FDA approved" is clearly no. A search on the FDA's Drugs@FDA database confirms no listing for retatrutide or its generic name, LY3437943. This status reflects its ongoing development pipeline without completed regulatory review.

Why Retatrutide Is Not Yet FDA Approved

Retatrutide requires successful completion of phase 3 trials to demonstrate long-term safety and efficacy. The FDA mandates rigorous data on thousands of patients before approval, a process that typically takes years. Eli Lilly initiated phase 3 in 2023, with topline results expected in 2025.

What Is Retatrutide and How Does It Work?

Retatrutide targets obesity by mimicking three key hormones, offering a multi-pronged approach to weight loss. Developed by Eli Lilly, it builds on the success of single- and dual-agonist drugs.

Overview of Retatrutide as a Weight Loss Drug

Retatrutide is an injectable medication designed for adults with obesity or overweight conditions with related health issues. Unlike approved drugs, its triple-action profile aims for greater weight reduction. Is retatrutide FDA approved? Not yet, but early trials position it as a potential game-changer.

For a deeper dive, read our guide on what is retatrutide.

Mechanism of Action: Triple Agonist Explained

Retatrutide activates GLP-1, GIP, and glucagon receptors:

GLP-1: Reduces appetite and slows gastric emptying, similar to semaglutide (Ozempic).
GIP: Enhances insulin response and fat metabolism, like in tirzepatide (Mounjaro).
Glucagon: Boosts energy expenditure by promoting fat burning.

This combination led to superior weight loss in phase 2 studies, per NEJM publication.[1]

Retatrutide Clinical Trial Status: Where Things Stand

Retatrutide's development is advancing through large-scale phase 3 trials. These studies are critical for answering "is retatrutide FDA approved" in the near future.

Phase 3 Trials and Key Milestones

Eli Lilly's TRIUMPH program includes multiple phase 3 trials:

TRIUMPH-1: Obesity without diabetes (NCT05556512).
TRIUMPH-2: With type 2 diabetes (NCT05929066).
TRIUMPH-3: Long-term cardiovascular outcomes.

Enrollment completed in several trials, with data readouts slated for 2025, according to ClinicalTrials.gov.[2]

Timeline for Potential FDA Submission

Lilly plans to submit an NDA to the FDA after phase 3 data, potentially in late 2025 or 2026. This follows phase 2 success announced in Lilly's investor update.[3]

Recent Updates on Retatrutide Trials

In September 2024, interim data reinforced efficacy. No major safety halts reported, keeping it on track.

For ongoing updates, see our article on retatrutide clinical trials.

Retatrutide Efficacy Results from Clinical Trials

Phase 2 data highlights retatrutide's potential for substantial weight loss, often exceeding current standards.

Weight Loss Outcomes in Phase 2 and 3 Data

In a phase 2 trial of 338 adults, participants lost:

17.5% body weight at 24 weeks (8mg dose).
Up to 24.2% at 48 weeks (12mg dose).

Phase 3 trials aim to confirm these in larger groups.[1]

Comparisons to Semaglutide and Tirzepatide

Drug	Max Weight Loss (Phase 2/3)
Retatrutide	~24% at 48 weeks
Semaglutide (Wegovy)	~15-17% at 68 weeks [4]
Tirzepatide (Zepbound)	~20-22% at 72 weeks [5]

Retatrutide showed numerically better results head-to-head.

Long-Term Efficacy Projections

Projections suggest sustained loss with lifestyle changes, but phase 3 will clarify maintenance post-treatment.

Explore more in retatrutide efficacy results.

Retatrutide Safety Data and Side Effects

Safety profiles mirror other incretin drugs, with mostly manageable issues.

Common Side Effects Reported in Trials

Gastrointestinal: Nausea (up to 47%), vomiting (24%), diarrhea (24%).
Dose-dependent; improved with titration.

Mild to moderate in >90% of cases.[1]

Serious Risks and Safety Concerns

Rare events included:

Gallbladder issues (2-3%).
Heart rate increases (transient).
No increased pancreatitis or thyroid tumors in trials.

Long-term risks under study.

Monitoring and Mitigation Strategies

Start low, go slow dosing minimizes sides. Regular check-ups for heart, liver function advised.

Details in retatrutide safety side effects.

Legal Status of Retatrutide: Availability and Regulations

Without approval, retatrutide access is restricted.

Is Retatrutide Legal to Buy or Use Now?

No legitimate sources exist outside trials. Compounded versions are risky and illegal for interstate sale per FDA warnings.[6] Is retatrutide FDA approved? No, so avoid black market.