Washington, D.C.—Former FDA Commissioner Scott Gottlieb told Congress on Wednesday that he’s uneasy that WalgreensandCVShave decided to start selling CBD products,according to CNBC.

CNBC quotes Gottlieb as saying at a House Appropriations Committee hearing: “We expressed concern yesterday, I did, about Walgreens and CVS stepping into this market. So you now see big-box stores seeking to market CBD products for some uses where the claims seem to be potentially over the line, for the treatment of pain for example.”

Gottlieb said FDA is exercising discretion in its enforcement of policies regarding CBD, but it has issued warning lettersto companies it considers to be using “over-the-line” claims.