- Shortages of the GLP-1 receptor agonists tirzepatide and semaglutide resolved in December 2024 and February 2025, respectively.
- A secret shopper study found that the majority of weight-loss clinics and medical spas in two states offered compounded tirzepatide and semaglutide after shortages were resolved.
- Over half of the suppliers combined their compounded GLP-1 drugs with B vitamins, and some products originated from unlicensed or disciplined facilities.
The market for compounded GLP-1 drugs remained robust despite the end of semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro, Zepbound) shortages, with many facilities adding ingredients like B vitamins and some operating with safety violations, a secret shopper study found.
Among 75 brick-and-mortar weight-loss clinics and medical spas across two states, 92% offered compounded semaglutide and 86.7% offered compounded tirzepatide, while one facility offered an unnamed triple agonist product, despite these products never receiving FDA approval.
Over half of the clinics (56%) offered compounded variations combined with B vitamins, while others added levocarnitine (6.7%) and glycine (5.3%), reported Michael J. DiStefano, PhD, of the University of Colorado Anschutz Medical Campus in Aurora, and colleagues.
“After declaring an end to the shortages of semaglutide and tirzepatide, the FDA stated that, by the end of May 2025, it would resume enforcement of the Federal Food, Drug and Cosmetic Act (FDCA), which prohibits compounding copies of FDA-approved products not in short supply,” the authors wrote in JAMA Health Forum.
The findings support the hypothesis that the FDA’s decision to resume FDCA enforcement prompted compounders to alter formulas by adding ingredients, they noted.
DiStefano told MedPage Today that his team wasn’t expecting the end of shortages to significantly curtail the compounded market.
“We were mainly interested in seeing how the product mix might have shifted,” he said. “And what we found was that many suppliers appear to have shifted toward compounding GLP-1s with some sort of added ingredient, like B vitamins or glycine.”
By adding B12 — often listed on product labels as methylcobalamin, hydroxocobalamin, or cyanocobalamin — some compounders claim to offer “personalized” versions of the drug. Tirzepatide maker Eli Lilly called this move an attempt to circumvent an FDA order to cease mass compounding after shortages ended. In March, Lilly published an open letter warning consumers against using compounded versions of tirzepatide containing vitamin B12 due to potential safety risks. In response, the Alliance for Pharmacy Compounding defended B12 as “a well-studied and remarkably benign drug.”
Unless prices for brand-name drugs drop dramatically, DiStefano said he doesn’t expect demand for compounded options to slow down anytime soon. “As potentially more effective options hit the market, like retatrutide, we may just see the demand shift regardless of whatever happens with the prices of existing options,” he added.
The cross-sectional study also highlighted notable licensing and regulatory issues among the 23 unique single-location compounding pharmacies identified as suppliers. Of the 21 state-licensed facilities whose credentials could be verified, four lacked active sterile compounding licenses. One facility had received two FDA warning letters since 2023 for sterile compounding violations, while three state-licensed facilities had faced state-level disciplinary actions — two of which specifically cited sterile compounding noncompliance.
Additionally, three pharmacies had an open FDA Form 483, which details substantial objectionable conditions observed by FDA investigators during an inspection, since early 2023 for objectionable sterile compounding practices, yet all remained open.
“Given that compounding GLP-1 receptor agonists requires sterile compounding, our findings indicate that patients using these products may be exposed to fibers, particles, or microorganisms that could increase the risks of infection and adverse events,” the researchers wrote.
Earlier this year, the FDA announced a crackdown on copycat weight-loss drugs, calling it a necessary move to safeguard consumers, as compounded drugs cannot be verified for quality, safety, and efficacy. In April, the FDA proposed removing three GLP-1 drugs from the 503B bulks list of active ingredients that outsourcing facilities can use to make compounded medicines, stating there was no clinical need for them.
Outsourcing facilities can generally only compound drugs using bulk ingredients if the drug is on the FDA’s drug shortage list or the 503B bulks list. Shortages of tirzepatide and semaglutide resolved in December 2024 and February 2025, respectively.
Assuming these findings can be generalized nationwide, the researchers estimated that more than 4,000 similar businesses offering compounded GLP-1 drugs may exist across the U.S.
For the study, mystery shoppers contacted brick-and-mortar businesses advertising GLP-1 drugs for weight loss in West Virginia and Oklahoma, two states chosen for their high obesity rates and mix of insurance types, from August to October 2025. Nurse practitioners or physician assistants conducted consultations more commonly than physicians. Most facilities (61.3%) required follow-up appointments at least once per month; only three businesses did not require any follow-up appointments. This contrasted with another recent secret shopper study, which found that two-thirds of online GLP-1 drug sellers did not require speaking with a clinician prior to receiving a prescription.
The researchers noted that their findings may not be generalizable to online-only telehealth platforms.
“There is a lot of diversity in the compounded GLP-1 market,” said DiStefano. “If you have a patient who you think could significantly benefit from these medications but cannot afford the branded options, it’s important to do research into the supplier. Reach out to a pharmacist or your state board of pharmacy.”
