Compounded GLP-1s Get ‘Secret Shopper’ Treatment

 Compounded GLP-1 products remain widely available in weight-loss clinics and medical spas despite resolution of the previous product shortages, new research suggested.

Widespread shortages of the GLP-1 medications semaglutide and tirzepatide beginning in 2022 led to a surge in the compounded drug market. The FDA permitted compounding during the shortages, but once the brand-name manufacturing supply stabilized in early 2025, the FDA said these companies could no longer make exact copies of the brand-name GLP-1s, although they were still permitted to make “patient-specific” formulations for reasons such as drug allergies or difficulty swallowing.

A “secret shopper” study conducted in 2025 in two US states identified high numbers of weight-loss clinics and spas advertising compounded GLP-1 products for weight loss. Many of these businesses reported using formulations containing additives, suggesting attempts to comply with the more stringent compounding rules. Inconsistencies were seen in sterile compounding licensures at some of the source facilities, and a few received FDA warnings or state licensing board disciplinary actions.

“The heterogeneity in product composition, oversight, and follow-up underscores the need for clearer standards, transparent supplier disclosure, and stronger monitoring to protect patients,” Michael J. DiStefano, PhD, of the Department of Clinical Pharmacy at the University of Colorado Anschutz Medical Campus, Aurora, Colorado, said recently at the Obesity Medicine Association 2026 meeting.

“As a clinician, if you are considering prescribing a compounded formulation of a GLP-1 for whatever reason, or if a patient comes to you and says they’re using this or considering using it…it is worth doing some homework to understand where the product might be coming from,” DiStefano told Medscape Medical News.

Asked to comment, session moderator Nicholas Pennings, DO, professor of family medicine at the Jerry M. Wallace School of Osteopathic Medicine at Campbell University, Buies Creek, North Carolina, told Medscape Medical News he wasn’t surprised by the findings. “We see it in our patient population. This is still an avenue whereby people get their medications…. I thought this was a very interesting study to give us some insights about things we suspect but don’t necessarily know.”

Pennings said there are several potential dangers in compounded products, which are not reviewed by the FDA for safety, efficacy, or quality. These risks include toxic ingredients, incorrect dosages, inactive drug, or development of antibodies. In addition, “It’s not just the drug, but the drug plus the delivery system,” such as the special coating used in oral semaglutide that keeps it from breaking down in the stomach.

“Given all the potential concerns about the quality and the safety of these compounded agents, as a physician, I encourage my patients to go directly to the manufacturer if their insurance doesn’t cover it as those prices are more reasonable now,” Pennings said.

Study Eyes Questionable Practices

In contrast to a previous study, DiStefano and colleagues had conducted in Colorado, a low-obesity state, this one was conducted in two states with high anticipated demand for GLP-1 drugs based on both high obesity rates and lack of Medicaid coverage for weight-loss medications.

Using a “secret shopper” script developed for the Colorado study, the investigators conducted interviews of 75 weight-loss clinics or spas advertising compounded GLP-1s. They asked the businesses about product availability, aspects of patient care and monitoring, and the source facility of the compounded products. They then linked the identified compounding facilities to publicly available licensing and inspection data.

Most offered compounded versions of both semaglutide and tirzepatide. Of 58 facilities that answered a question about use of additives, 44 said they did have such products available. The most common additives were vitamin B, levocarnitine, and glycine.

This represents a legally murky area, DiStefano noted. “If they’re adding B vitamin and making a claim it will improve a person’s energy or reduce nausea associated with the GLP-1, this is arguably a specific patient need they’re meeting…. But there’s a gray area here, where you can just imagine that there’s a lot of illegitimate prescribing under the auspices of this ‘patient-specific’ criterion.”

Subsequent investigation into public records of 23 of the compounding facilities identified during the “secret shopper” calls showed that all but one was licensed by the state. Of the 21 503A facilities, or traditional pharmacies overseen by state boards of pharmacy, just 17 were licensed for sterile compounding.

A total of four facilities had received disciplinary actions from either the state board or the FDA since 2023, of which three were related to sterile compounding practices. Clinicians considering prescribing these products should verify the compounding facility’s licensure status with the FDA or state board, DiStefano advised.

A ‘Very Dynamic’ Weight-Loss Drug Market

Evolving factors could change the current picture. The Medicare Drug Price Negotiation Program established a maximum fair price for semaglutide, to take effect in 2027. This “may exert downward pricing pressure across the weight-loss drug market and beyond Medicare,” DiStefano said in his presentation.

Oral semaglutide and orforglipron are now FDA-approved for weight loss, with other oral candidates in development, while generic injectable semaglutide is expected this year in some countries.

“I think it’s hard to know what will happen with this market going forward,” DiStefano told Medscape Medical News, adding, “If a drug with amazing weight loss that has fewer side effects and is not inconvenient to take, is approved at some point in the future, there could be demand for compounded versions of it if its price is initially quite high, but it’s hard to say. The market is quite dynamic, and these drugs have significant demand behind them, in a way that others have not.”

DiStefano has no industry disclosures. He has received funding for research outside this work from Arnold Ventures, PhRMA Foundation, National Pharmaceutical Council, and the Institute for Clinical and Economic Review. Pennings is a speaker for Novo Nordisk and has served on advisory boards for Abbott and Eli Lilly. He is also director of clinical education for the Obesity Medicine Association.

https://www.medscape.com/viewarticle/secret-shopper-study-finds-risks-compounded-glp-1s-2026a1000car