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.”