Unauthorized Weight Loss Medications: Promise and Peril

Michael C. Harding, MD, MPH
February 2, 2026

Glucagon-like peptide-1 (GLP-1) receptor agonists, such as semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro, Zepbound), have transformed the landscape of obesity medicine. A 2025 analysis identified nearly 60 million individuals who were prescribed a GLP-1 receptor agonist for obesity alone between 2010 and 2025. During this period, the proportion of individuals with obesity (and without diabetes) receiving these prescriptions surged from 0.04% to 7.1%.

GLP-1 receptor agonist prescriptions for type 2 diabetes are generally covered by most insurance plans, but coverage for weight management remains limited. Although drug shortages are stabilizing and manufacturers Novo Nordisk and Eli Lilly are lowering out-of-pocket costs for some patients, many patients are turning to unapproved or compounded medications for weight loss. Compounding pharmacies exist to improve the personalization of medicine. Under the direction of a prescribing physician, these pharmacies can remove inactive ingredients or components that may cause patient harm (such as potential allergens), change the route of administration, or combine multiple medications into a single product. However, the activities of compounding pharmacies were never “intended to replace brand drugs sold commercially.” Specifically, Section 503B of the Federal Food, Drug, and Cosmetic Act restricts compounding of drugs that are “essentially a copy of one or more FDA-approved drugs.”

During the initial production shortage, compounding pharmacies were permitted to compound semaglutide and tirzepatide to cover the gap in patient need. Since the resolution of the drug shortage, the US Food and Drug Administration (FDA) has issued guidance to compounding pharmacies to cease production of these products, but a billion-dollar industry is not likely to give up the money so readily. Currently, many pharmacies circumvent the regulatory restrictions by combining the GLP-1 receptor agonists with another relatively benign ingredient, such as niacin or cyanocobalamin. Additionally, a Texas-based compounding pharmacy recently filed an antitrust lawsuit against Eli Lilly and Novo Nordisk for their monopolization of GLP-1 receptor agonist production. Regardless of the legal status of compounded GLP-1 receptor agonists, the American Association of Clinical Endocrinology and the American Diabetes Association have recommended against their use, citing concerns about safety, quality, and effectiveness.

Additional unapproved weight loss medications pose risks to patients. The growth hormone-releasing hormone analogue tesamorelin has been touted by some social media influencers as a way to reduce visceral fat and abdominal obesity, despite being indicated only for individuals with HIV. The American Association of Clinical Endocrinology and the American College of Endocrinology have issued a joint statement about the off-label use and misuse of common hormones for weight loss, such as thyroid hormone, growth hormone, and testosterone. Finally, although the investigational agents Cagrilintide (a long-acting amylin analogue) and Retatrutide (a combined GLP-1, GIP [glucose-dependent insulinotropic polypeptide], and glucagon receptor agonist) have shown promising data in phase II clinical trials, they are not yet FDA approved (ie, they cannot be used in compounding under federal law).

As demand for effective obesity treatments continues to outpace insurance coverage and regulatory clarity, patients and clinicians find themselves navigating a rapidly evolving—and often precarious—therapeutic landscape. GLP-1 receptor agonists represent a genuine breakthrough in obesity medicine, but the rise of compounded, unapproved, and investigational alternatives underscores the tension between access and safety. Family physicians must be informed to counsel patients on the risks associated with compounded and off-label weight loss medications.