For all the hype surrounding GLP-1 weight loss medications like Wegovy and Zepbound, these drugs don’t work for everyone. Nearly 17% of people on these medications are considered “non-responders,” leaving them looking for a different solution. But there’s a buzzy new medication waiting in the wings. While it’s not yet approved by the Food and Drug Administration (FDA), people are already seeking it out.
It’s called retatrutide, and it’s a triple-agonist medication, which means it acts on three different receptors in the body. By comparison, Wegovy (semaglutide) acts on one receptor, while Zepbound (tirzepatide) works on two.
Retatrutide is already being hailed as a game changer in an area of health that’s already welcomed plenty of impressive medications in the past few years. In fact, clinical trial results show that it’s so effective for weight loss that some people have dropped out of the trials because they felt that they lost too much weight.
But retatrutide is still being tested in clinical trials. Eli Lilly, which makes reatrutide and Zepbound, hasn’t even submitted the trial results yet to the FDA for approval. So this is still an experimental medication—and versions of it are being sold online for cheap.
Mir Ali, MD, medical director of MemorialCare Surgical Weight Loss Center at Orange Coast Medical Center in Fountain Valley, California, tells SELF that retatrutide is “not really available” for use just yet, short of signing up for a clinical trial. There is no set timeline for when it will hit the market, given that clinical trial results have not yet been submitted to the FDA.
If you’ve struggled with losing weight on a GLP-1 medication or just want to pay significantly less for what appears to be the next big thing in weight loss drugs, it’s understandable to be tempted to add this to your cart. Here’s why doctors recommend resisting the urge.
What is retatrutide?
Retatrutide is similar to GLP-1 medications in a few ways. Namely, it’s used for weight loss and is given once a week through an injection. Like Wegovy, Ozempic, and Zepbound, retatrutide works by reducing appetite and slowing digestion.
But retatrutide has more going on than that. This medication acts on three hormone receptors in the body—glucagon-like peptide-1 (GLP-1), gastric inhibitory polypeptide (GIP), and glucagon (GCG). “This is the first one in the pipeline to work on three different receptors,” says Dr. Ali. “The theory is that the more receptors it affects, the more effective the drug will be.”
The medication is currently in phase-three clinical trials, and it’s had some impressive results that suggest it could be the most effective drug for weight loss yet. The latest clinical trial results show that participants lost an average of 28.7% of their body weight on the highest dose of retatrutide over 68 weeks. By comparison, tirzepatide users lost an average of 15% to 22.5% over 72 weeks during clinical trials, and semaglutide users lost 10% to 15% of their body weight over 68 weeks during clinical trials.
How are people finding it?
It takes a little detective work, but there are some pharmacies that are selling the drug online.
In fact, this has become such an issue that the FDA issued a press release in early February, stressing that it’s illegal to sell retatrutide (and fellow experimental weight loss medication cagrilintide) right now. That includes picking up the medication from a compounding pharmacy.
“Retatrutide and cagrilintide cannot be used in compounding under federal law,” the release states. “Additionally, these are not components of FDA-approved drugs and have not been found safe and effective for any condition.”
The FDA also noted that its officials have issued warning letters to companies that are distributing these medications.
Doctors make a very important point about taking retatrutide right now.
This is hardly shocking, but doctors really want you to take a pass on using retatrutide before it’s FDA-approved.
“People should wait to take medications until they are approved by the FDA to maximize safety,” Richard Siegel, MD, codirector of the Diabetes and Lipid Center at Tufts Medical Center and endocrinologist at Tufts Medicine Weight & Wellness Center–Stoneham, tells SELF. “All scientific data in animals initially and then humans are carefully reviewed by the FDA for any signals that a medication may be harmful.”
That includes side effects you might experience now or in the future, Dr. Ali points out. Compounding pharmacies have become a gray area. They’re able to legally produce and sell their own versions of popular medications when the FDA-approved versions are in shortage. But technically this is no longer legal once the medications are out of shortage.
But compounded drugs aren’t carefully regulated and may not even have the same ingredients or concentration as the medication they’re designed to mimic, Dr. Siegel says. “While these medications may be safe, there is less oversight in their production,” he says.
Dr. Ali warns against going directly through a compounding pharmacy, noting that it’s safer to work with your health care provider if you plan to go this route. “The worst-case scenario is that you’re getting something unsafe or ineffective,” he says.
But, with all medications, Dr. Ali says it’s best to use the FDA-approved version whenever possible. “It’s going to work in a predictable way, and the side effect profile will be well-studied,” he says.
What to do if you’re a “non-responder”?
Dr. Siegel points out that there are a lot of options to lose weight right now. And, if you haven’t had success on one, he recommends talking to your healthcare provider about trying a different medication or strategy. If you haven’t had luck while working with a primary care physician, Dr. Ali suggests seeing an obesity medicine specialist who will be more knowledgeable about treatment options.
“Medications for weight management are a powerful tool that should be used together with a comprehensive lifestyle plan focusing on self-monitoring, optimal nutrition, and an exercise prescription, including both aerobic and resistance components,” Dr. Siegel says. Meaning, people who have the best results do more than take medication—they also focus on nutrition and exercise.
If you’re interested in taking a weight loss medication or your existing treatment isn’t working, talk to a healthcare provider who specializes in this area. “These medications are designed for people with significant weight to lose,” Dr. Ali says. “Most likely, they will need to be taken long-term.” That makes getting a well-vetted medication from a reputable source even more important, he points out.
Related:
- On a GLP-1? This Is the Workout Plan That Helps You Keep Muscle
- How GLP-1s Are Quietly Reshaping Gym Culture
- The Ultimate Grocery List for GLP-1 Users, According to a Dietitian
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