High demand has created a market for compounded versions of the drug best known as Ozemic or Wegovy, but doctors and the FDA say those versions come with risks.

WeightWatchers will begin selling compounded alternatives to certain weight-loss drugs that are experiencing shortages. Why it matters: Federal law allows companies to sell compounded versions of drugs that are on the FDA's shortages list — which has led to a surge of copycats to the newly popular class of GLP-1 injections.