Retatrutide vs. Currently Available GLP-1 Medications: What the Data Shows
Medically reviewed by Dr. Michael Koehler, MD
New data on retatrutide continues to generate excitement. As an investigational triple agonist, it has shown impressive weight-loss results in clinical trials. However, when we compare it with the currently available GLP-1 medications (semaglutide and tirzepatide) the picture becomes clearer for most patients.
At Affinity Whole Health, we follow the latest research closely so we can give honest, evidence-based guidance. Here’s what the most current published studies show.
How These Medications Differ
Semaglutide has the most clinical experience and long-term safety data.
Tirzepatide adds GIP receptor activity for greater appetite suppression and weight loss.
Retatrutide adds glucagon receptor activation, which increases energy expenditure. This helps explain its higher numbers in trials — but it also brings additional considerations.
What the Latest Studies Show
Semaglutide has been studied extensively for years. It typically produces around 15% average weight loss and carries the strongest cardiovascular outcome data among GLP-1 medications.
Tirzepatide in the landmark SURMOUNT-1 trial, tirzepatide produced up to 20.9% average weight loss at 72 weeks.
More recently, the SURMOUNT-5 trial directly compared tirzepatide head-to-head against semaglutide. Tirzepatide achieved 20.2% weight loss versus 13.7% with semaglutide at 72 weeks — a meaningful advantage.
The most recent data on Retatrutide comes from the Phase 3 TRIUMPH-1 trial (topline results announced May 2026). At 80 weeks:
4 mg dose: 19.0% weight loss
9 mg dose: 25.9% weight loss
12 mg dose: 28.3% weight loss (with 45.3% of participants achieving ≥30% loss)
These results build on the earlier Phase 2 data published in the New England Journal of Medicine in 2023.
Important context on dosing: Retatrutide at its lowest studied dose performed similarly to tirzepatide. The larger gains appeared at the higher doses, where side effects also increased.
Side Effects and Tolerability
All three medications may cause gastrointestinal side effects, particularly when first starting and during dose escalation.
Semaglutide has the most mature long-term safety data.
Tirzepatide generally offers strong efficacy with a manageable side-effect profile similar to semaglutide's.
Retatrutide at higher doses has shown increased rates of nausea, vomiting, heart rate elevation, and dysesthesia (tingling sensations).
For many patients, the extra weight loss seen with higher-dose retatrutide may not justify the increased side-effect burden when tirzepatide and semaglutide already deliver excellent results.
Availability and Regulatory Reality
This remains one of the most important distinctions:
Semaglutide and tirzepatide are FDA-approved medications for weight loss. They are also available through legitimate channels, including high-quality compounded versions from licensed U.S. pharmacies.
Retatrutide remains investigational and is not FDA-approved for any use. It is not available from licensed U.S. compounding pharmacies. The FDA has issued warnings regarding companies marketing compounded versions of this unapproved drug.
We addressed the risks of unverified online retatrutide products in a previous post: The Retatrutide You’re Seeing Online Isn’t Real.
Our Current Recommendation
Based on the most up-to-date published data:
Semaglutide remains an excellent, well-established option with the longest track record and proven cardiovascular benefits.
Tirzepatide currently offers the best overall balance of stronger weight loss, tolerability, and immediate availability for most patients.
Retatrutide shows exciting potential but is not yet ready for clinical use. We will continue monitoring results from ongoing trials, including the direct head-to-head TRIUMPH-5 study.
At Affinity Whole Health, we currently offer compounded semaglutide and compounded tirzepatide through licensed, FDA-registered compounding pharmacies. Please note that compounded medications are not FDA-approved, as they are prepared on an individual patient basis when a patient’s needs cannot be met by commercially available FDA-approved products. All of our compounded formulations are sourced from reputable pharmacies that follow strict quality and safety standards, with personalized dosing and close medical supervision. Treatments include ongoing support for nutrition, muscle preservation, and overall metabolic health.
Bottom Line
Semaglutide gives you proven results with the most experience. Tirzepatide currently delivers the strongest combination of effectiveness and practicality among available options. Retatrutide may one day raise the bar — but it is not yet approved or accessible through legitimate channels.
We’re focused on helping you achieve the best possible results with the safest, most reliable medications available today.
This article is for educational purposes only and is not medical advice. Always consult with a licensed healthcare provider before starting treatment. Compounded medications are not FDA-approved.