WASHINGTON — An FDA advisory panel is reviewing whether compounding pharmacies should be allowed to manufacture seven specific peptides, which could make them easier to access in the United States.

Right now, substances like BPC-157 and TB-500 are being obtained on the gray market, typically through online sellers or social media. They are usually shipped in from overseas and designated for research, not human consumption.

These substances are often promoted online as a way to support muscle and tissue healing. But they have not gone through clinical trials, meaning they have not been tested for safety or efficacy and are not FDA-approved.

What federal officials are now weighing is whether Americans should be able to access these products through prescriptions from compounding pharmacies. The lack of evidence about the benefits and risks of these substances has many doctors concerned.

So far, the panel has voted in favor of making some of these peptides more accessible, Youri Benadjaoud of ABC News said, "though ultimately the final decision will be up to FDA leadership."