A little-known advisory group to the US Food and Drug Administration will meet this week to mull over whether to ease restrictions on certain peptides. The injectables are popular among wellness influencers and some doctors, who say they improve muscle recovery, reduce inflammation, promote longevity or simply boost your overall health.

The committee will discuss whether compounding pharmacies can make the peptides in question. But FDA scientists say there’s little — if any — evidence they work in humans.

As regulators weigh whether pharmacies can legally compound wellness peptides, companies are preparing for a repeat of the GLP-1 boom—only this time with even murkier science.