Key Takeaway
If you have been following the GLP-1 space, you have probably heard about retatrutide. This retatrutide guide covers everything you need to know about the first triple-agonist medication in development for weight management.
If you have been following the GLP-1 space, you have probably heard about retatrutide. This retatrutide guide covers everything you need to know about the first triple-agonist medication in development for weight management. Unlike current options that target one or two hormone receptors, retatrutide activates three. And the early clinical trial data has turned heads across the medical world.
Key Takeaways: - Understand what is retatrutide and how does it work - Phase 2 Trial Results: What the Data Shows - When Will Retatrutide Be Available - Learn how retatrutide compares to current options
So what makes this drug different? And when might it actually become available? Let's break it down.
What Is Retatrutide and How Does It Work?
Retatrutide is an investigational medication developed by Eli Lilly. It targets three hormone receptors at once: GLP-1, GIP, and glucagon. That is why researchers call it a "triple agonist."
Each of these receptors plays a role in how your body manages weight and blood sugar. GLP-1 slows digestion and reduces appetite. GIP helps regulate insulin and may improve how your body processes fat. Glucagon increases energy expenditure and promotes fat breakdown in the liver.
By hitting all three targets, retatrutide may offer more powerful results than medications that only activate one or two receptors. Current GLP-1 medications like compounded semaglutide target the GLP-1 receptor alone. Tirzepatide targets both GLP-1 and GIP. Retatrutide adds glucagon to that mix.
"We now have cardiovascular outcomes data showing semaglutide reduces MACE events by 20% in people with obesity, independent of diabetes status. The SELECT trial changed how we think about these medications.") Dr. A. Michael Lincoff, MD, Cleveland Clinic, lead author of SELECT
This triple action could mean greater weight loss, better blood sugar control, and improved liver health. But it is still being studied, and the FDA has not yet approved it.
If you are curious about how existing GLP-1 medications work, check out our or our .
Phase 2 Trial Results: What the Data Shows
The Phase 2 clinical trial results for retatrutide were presented at the American Diabetes Association conference and published in the New England Journal of Medicine. The numbers were striking.
Participants taking the highest dose of retatrutide lost an average of 24.2% of their body weight over 48 weeks. That is roughly one-quarter of their starting weight. To put this in perspective, semaglutide trials showed about 15% weight loss, and tirzepatide trials showed about 22%.
Free Download: GLP-1 Medication Comparison One-Pager See how retatrutide stacks up against semaglutide, tirzepatide, and other GLP-1 options in one easy chart. Get yours free (we'll email it to you instantly. [Email Input] [Download Button]
The most common side effects were similar to other GLP-1 medications. Nausea, diarrhea, and vomiting were reported, though they tended to be mild to moderate. Most side effects decreased over time as the body adjusted.
It is important to note that Phase 2 trials are smaller than Phase 3 trials. They show promise, but larger studies are needed to confirm safety and effectiveness. Eli Lilly has already started Phase 3 trials, which will involve thousands of participants.
When Will Retatrutide Be Available?
As of early 2026, retatrutide is still in Phase 3 clinical trials. These trials typically take two to three years to complete. After that, Eli Lilly must submit the data to the FDA for review, which can take another 6 to 12 months.
Check your GLP-1 eligibility
Use our free BMI Calculator to see if you may qualify for physician-supervised GLP-1 therapy.
Try the BMI Calculator →Based on current timelines, the earliest retatrutide could reach the market is likely 2027 or 2028. This timeline could shift depending on trial results and regulatory decisions.
If you are looking for effective treatment options available today, FormBlends offers personalized compounded medications prepared by licensed US-based 503A pharmacies. Our providers can help you find the right fit.
How Retatrutide Compares to Current Options
Understanding where retatrutide fits in the broader GLP-1 space helps you make informed decisions about your treatment path.
Semaglutide is a single-agonist that targets GLP-1 only. It is the most widely prescribed GLP-1 medication and has strong clinical data behind it. Tirzepatide is a dual-agonist targeting GLP-1 and GIP. It showed higher weight loss numbers than semaglutide in head-to-head trials.
Retatrutide adds the glucagon receptor, which may boost energy expenditure on top of appetite reduction. Early data suggests this could translate to greater fat loss, particularly liver fat. In the Phase 2 trial, more than 80% of participants with fatty liver disease saw complete resolution of their condition.
For a detailed side-by-side look at all available GLP-1 medications, see our .
The key takeaway? The science of weight management keeps advancing. But you do not need to wait for future drugs to start your weight loss.
Frequently Asked Questions
Is retatrutide approved by the FDA?
No, retatrutide is not yet FDA-approved. It is currently in Phase 3 clinical trials conducted by Eli Lilly. If trials are successful, it may be submitted for FDA approval in the coming years.
How much weight can you lose on retatrutide?
In Phase 2 trials, participants on the highest dose lost an average of 24.2% of their body weight over 48 weeks. Individual results varied, and Phase 3 data is still pending.
What are the side effects of retatrutide?
The most common side effects in trials included nausea, diarrhea, vomiting, and constipation. These were generally mild to moderate and tended to improve over time. Learn more about managing GLP-1 side effects in our .
How is retatrutide different from semaglutide or tirzepatide?
Retatrutide targets three hormone receptors (GLP-1, GIP, and glucagon), while semaglutide targets one (GLP-1) and tirzepatide targets two (GLP-1 and GIP). The additional glucagon activity may increase energy expenditure and fat burning.
Can I get retatrutide through FormBlends?
Retatrutide is not currently available through FormBlends or any other provider, as it has not yet received FDA approval. However, FormBlends offers other effective GLP-1 treatment options with licensed providers.
What's Your Next Move?
You have the information. Now let a licensed provider help you put it into action. FormBlends makes it simple) answer a few questions and get a personalized recommendation.
Sources & References
- Pi-Sunyer X, Astrup A, Fujioka K, et al. A Randomized, Controlled Trial of 3.0 mg of Liraglutide in Weight Management. N Engl J Med. 2015;373(1):11-22. Doi:10.1056/NEJMoa1411892
- Marso SP, Daniels GH, Tanaka K, et al. Liraglutide and Cardiovascular Outcomes in Type 2 Diabetes. N Engl J Med. 2016;375(4):311-322. Doi:10.1056/NEJMoa1603827
- Wilding JPH, Batterham RL, Calanna S, et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity. N Engl J Med. 2021;384(11):989-1002. Doi:10.1056/NEJMoa2032183
- Davies M, Færch L, Jeppesen OK, et al. Semaglutide 2.4 mg once a week in adults with overweight or obesity, and type 2 diabetes (STEP 2 (Davies et al., Lancet, 2021)). Lancet. 2021;397(10278):971-984. Doi:10.1016/S0140-6736(21)00213-0
- Wadden TA, Bailey TS, Billings LK, et al. Effect of Subcutaneous Semaglutide vs Placebo as an Adjunct to Intensive Behavioral Therapy on Body Weight in Adults With Overweight or Obesity (STEP 3 (Wadden et al., JAMA, 2021)). JAMA. 2021;325(14):1403-1413. Doi:10.1001/jama.2021.1831
- Garvey WT, Batterham RL, Bhatt DL, et al. Two-Year Effects of Semaglutide in Adults with Overweight or Obesity (STEP 5 (Garvey et al., Nat Med, 2022)). Nat Med. 2022;28:2083-2091. Doi:10.1038/s41591-022-02026-4
- Lincoff AM, Brown-Frandsen K, Colhoun HM, et al. Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes. N Engl J Med. 2023;389(24):2221-2232. Doi:10.1056/NEJMoa2307563
- Jastreboff AM, Aronne LJ, Ahmad NN, et al. Tirzepatide Once Weekly for the Treatment of Obesity. N Engl J Med. 2022;387(3):205-216. Doi:10.1056/NEJMoa2206038
- Garvey WT, Frias JP, Jastreboff AM, et al. Tirzepatide once weekly for the treatment of obesity in people with type 2 diabetes (SURMOUNT-2 (Garvey et al., Lancet, 2023)). Lancet. 2023;402(10402):613-626. Doi:10.1016/S0140-6736(23)01200-X
- Wadden TA, Chao AM, Engel S, et al. Tirzepatide after intensive lifestyle intervention in adults with overweight or obesity (SURMOUNT-3 (Wadden et al., Nat Med, 2023)). Nat Med. 2023. Doi:10.1038/s41591-023-02597-w
- Aronne LJ, Sattar N, Horn DB, et al. Continued Treatment With Tirzepatide for Maintenance of Weight Reduction in Adults With Obesity (SURMOUNT-4 (Aronne et al., JAMA, 2024)). JAMA. 2024;331(1):38-48. Doi:10.1001/jama.2023.24945
- Malhotra A, Grunstein RR, Fietze I, et al. Tirzepatide for the Treatment of Obstructive Sleep Apnea and Obesity. N Engl J Med. 2024;391:1193-1205. Doi:10.1056/NEJMoa2404881
This article is for educational purposes only and does not constitute medical advice. Always consult with a licensed healthcare provider before starting, changing, or stopping any medication or supplement. FormBlends connects you with licensed providers who can evaluate your individual health needs.
Last updated: 2026-03-24