FDA Warning on Unapproved Weight Loss Drugs: What Patients Need to Know

The FDA has warned the public about the sale of unapproved weight loss drugs — products marketed for weight loss that have never gone through FDA review for safety, effectiveness, or manufacturing quality. These include counterfeit or mislabeled versions of GLP-1 medications like semaglutide and tirzepatide, products sold through unverified online sellers, and some imported preparations. The agency cautions that unapproved products may contain incorrect doses, harmful contaminants, or no active ingredient at all. Patients are urged to obtain GLP-1 medications only through a licensed prescriber and a state-licensed pharmacy.

Only four brand-name GLP-1 products are FDA-approved for weight management or diabetes: Ozempic and Wegovy (semaglutide), and Mounjaro and Zepbound (tirzepatide). Saxenda (liraglutide) is also approved for chronic weight management. Compounded GLP-1 drugs are NOT FDA-approved — they have not been reviewed for safety, effectiveness, or quality. A seller that calls compounded semaglutide "FDA-approved," "generic Ozempic," or "generic Wegovy" is misrepresenting the product. Check that your medication comes in the manufacturer packaging with a National Drug Code (NDC) and is dispensed by a licensed U.S. pharmacy.

Compounded GLP-1 drugs are not FDA-approved and carry risks the approved brand-name products do not, including variable concentration, dosing errors, and inconsistent sterility. A 2026 pharmacovigilance study found adverse event rates associated with compounded GLP-1 products that differ meaningfully from the approved versions. Dosing errors tied to differences in concentration and dosing units have been reported to poison control centers. If you use a compounded product, it should only come from a verified 503A or 503B pharmacy with a valid prescription, ideally when an FDA-approved product is genuinely unavailable.

Run five checks: (1) 503B outsourcing facilities must be registered with the FDA and appear on the FDA registered outsourcing facilities list; (2) any pharmacy must hold an active license in your state — verify through your state board of pharmacy; (3) look for accreditation such as PCAB or ACHC for sterile compounding; (4) the pharmacy should be transparent about the source of its active pharmaceutical ingredient and provide a certificate of analysis on request; and (5) a legitimate seller will never claim a compounded drug is "FDA-approved." Walk away from any seller that refuses to name its pharmacy, ships from outside the U.S., or advertises deep discounts with no medical evaluation.

The FDA statement on compounding using bulk drug substances explains which active ingredients compounders are legally permitted to use. The agency has proposed excluding semaglutide, tirzepatide, and liraglutide from the 503B bulk drug substances list, meaning large-scale outsourcing facilities would no longer be permitted to compound essentially copies of those drugs once the shortage is resolved. As availability of branded GLP-1 products normalizes, the regulatory window for routine compounded GLP-1 copies is closing. Patients relying on compounded products should plan a transition to branded medication with their prescriber.

Red flags include: no requirement for a real medical evaluation or licensed-prescriber follow-up; prices dramatically below the branded product with no explanation; refusal to name the dispensing pharmacy; shipping from outside the United States; labeling in a foreign language or unfamiliar units; claims that a compounded product is "FDA-approved" or a "generic"; and aggressive social media advertising. The FDA warns that patients buying from such sources risk receiving counterfeit, contaminated, or incorrectly dosed products.