The compounded weight-loss injections advertised for a few hundred dollars a month are frequently not chemically identical to the drugs that were studied in clinical trials. Some contain a different molecular form of the active ingredient. Many contain added substances that have no established weight-loss benefit and that have never been tested in combination with a GLP-1 medication in humans.
That is the assessment Stanford Medicine clinicians laid out in guidance published this month, aimed at the large number of Americans who turned to compounding pharmacies for cost reasons. At the 2024 peak, close to one in three people taking a GLP-1 drug in the United States reported obtaining it from a compounder.
