FDA & Government Peptide News: 10 Latest Stories on Tirzepatide & GLP-1 Regulation

On April 30, 2026, the FDA published a proposed determination that semaglutide, tirzepatide, and liraglutide do not meet the statutory criteria for inclusion on the 503B Bulks List. Under 21 U.S.C. § 353b, an active pharmaceutical ingredient may be compounded in bulk by a 503B outsourcing facility only if it is on the FDA's published Bulks List or on the agency's drug shortage list. With semaglutide removed from the shortage list in February 2025 and tirzepatide removed in December 2024, the only remaining legal pathway for industrial-scale 503B compounding of these molecules was bulks-list inclusion.

The FDA's analysis concludes that there is no current clinical need for outsourcing-facility compounding of these three molecules from bulk API, since FDA-approved products (Wegovy, Ozempic, Zepbound, Mounjaro, Saxenda, Victoza) are commercially available and meet patient need. The proposal explicitly rejects affordability and insurance access as constituting clinical need within the meaning of the statute.

The proposal does not affect 503A patient-specific compounding by state-licensed pharmacies, which remains legal where each prescription is supported by individualized medical-necessity documentation and the dispensing pharmacy operates under USP <797> sterile-compounding standards. It does, however, foreclose the path that enabled the 30%-of-supply compounding boom of 2024.

On May 18, 2026, the FDA issued a warning letter to ProRx, a 503B outsourcing facility, citing its continued production of compounded tirzepatide after the tirzepatide shortage was resolved in late 2024. Under section 503B of the FD&C Act, an outsourcing facility may compound a drug product from bulk drug substances only if the drug is on the FDA's 503B Bulks List or on the active shortage list. Tirzepatide was never on the Bulks List, and the shortage was resolved before the cited compounding activity.

Beyond the bulk-substance citation, the letter documented unsanitary conditions in sterile drug production, labeling deficiencies on several lots, and inadequate adverse-event reporting procedures. The agency required ProRx to cease compounding of the cited drug products and to submit a corrective-action plan within 15 working days.

ProRx reportedly ceased production of the cited products in April 2026, before the formal letter was issued. The cadence of these warning letters has been steady through 2025 and 2026: more than 55 warning letters were issued to online sellers of compounded GLP-1s in September 2025 alone, and additional letters have continued at roughly monthly intervals.

On February 6, 2026, the FDA issued a press release titled “FDA Intends to Take Action Against Non-FDA-Approved GLP-1 Drugs.” The release laid out the agency's enforcement posture against (1) compounded GLP-1 products that are not the result of individualized prescribing, (2) products containing salt forms of tirzepatide or semaglutide that the agency has not recognized as active pharmaceutical ingredients, and (3) marketing claims that imply equivalence to FDA-approved Mounjaro®, Zepbound®, Ozempic®, or Wegovy®.

The release built on the September 2025 wave of 55+ warning letters to online sellers of compounded GLP-1s and signaled the more structural action that would follow in April with the 503B Bulks-List exclusion proposal. The February release described the harms the agency was addressing: dosing errors from multi-dose vials, adverse-event reports exceeding 455 for compounded semaglutide and 320 for compounded tirzepatide as of early 2025, and counterfeit products entering the market through online channels.

The release was the first public confirmation from the agency that the shortage-era enforcement-discretion window had closed and would not re-open absent a new statutory pathway.

In Q1 2026 the FDA approved orforglipron (brand: Foundayo), Eli Lilly's once-daily small-molecule oral GLP-1 receptor agonist, for chronic weight management in adults with obesity (BMI ≥ 30) or overweight (BMI ≥ 27) with at least one weight-related comorbidity. Foundayo is the first new-molecule oral GLP-1 FDA-approved for weight management; the previously approved oral GLP-1, Rybelsus (semaglutide), is approved only for type 2 diabetes.

Pivotal evidence comes from the ATTAIN-1 trial program, which compared orforglipron to placebo and to active injectable comparators. Foundayo is not a tirzepatide product and is not a dual GLP-1 / GIP receptor agonist; it is a single GLP-1 receptor agonist administered as a once-daily pill.

The approval changes the market structure of the GLP-1 telehealth segment. Ro signed a deal with Eli Lilly in April 2026 to prescribe Foundayo alongside its existing semaglutide and tirzepatide offerings. Multiple other telehealth providers have signaled plans to add Foundayo to their formularies. The approval does not change the status of compounded tirzepatide, which remains a separate, non-FDA-approved product category.

In December 2024 the FDA approved Zepbound (tirzepatide) for adults with moderate-to-severe obstructive sleep apnea and obesity, on the strength of the SURMOUNT-OSA trial program. SURMOUNT-OSA randomized adults with moderate-to-severe OSA and obesity to tirzepatide or placebo for 52 weeks. The trial demonstrated significant reductions in the apnea-hypopnea index (AHI) and in body weight, with a meaningful proportion of patients achieving control of OSA severity criteria.

Zepbound (tirzepatide) is manufactured by Eli Lilly and Company. It was originally approved by the FDA in November 2023 for chronic weight management in adults with obesity (BMI ≥ 30) or overweight (BMI ≥ 27) with at least one weight-related comorbidity. The December 2024 OSA indication is an expansion of that label.

The OSA indication is clinically significant because it is the first time a drug has been FDA-approved specifically for OSA in adults with obesity — a population for whom CPAP is the standard of care but adherence is often limited.

On October 2, 2024, the FDA published a statement determining that the shortage of tirzepatide injection had been resolved. The agency stated that, after consulting with the manufacturer, present and projected national demand could be met by FDA-approved product supply. Subsequent guidance set enforcement-discretion windows: state-licensed pharmacies (503A) and outsourcing facilities (503B) had defined wind-down periods after which compounding of tirzepatide from bulk substance was no longer permitted on shortage-based grounds.

The semaglutide shortage was separately resolved in February 2025, with similar 503A and 503B wind-down periods.

Between shortage resolution and the April 2026 503B Bulks-List exclusion proposal, the FDA's posture had been one of cumulative escalation: warning letters in September 2025 (55+), the February 2026 “intent to take action” press release, and the May 2026 ProRx warning letter all sit on this timeline.

As of early 2025, the FDA's adverse-event tracking for compounded GLP-1 products had recorded more than 455 reports linked to compounded semaglutide and more than 320 reports linked to compounded tirzepatide. A meaningful share of these reports involved dosing errors from patients drawing incorrect doses from multi-dose vials — in some cases, ten-fold overdoses requiring hospitalization for severe nausea, vomiting, dehydration, or pancreatitis.

The dosing-error pattern is structural rather than incidental. Compounded GLP-1 products are commonly distributed in multi-dose vials with patient-administered syringes, whereas FDA-approved Wegovy, Zepbound, Ozempic, and Mounjaro are distributed in single-dose, fixed-dose pen injectors specifically designed to prevent over-aspiration. The FDA has cited the multi-dose vial format as a recurring contributor to the AE reports.

Counterfeit products entering the U.S. market through online channels have further reinforced the agency's enforcement focus. The agency has expanded import alerts on bulk API not on its recognized “green list” of FDA-inspected manufacturers.

The September 16, 2025 wave of warning letters targeted online sellers of compounded GLP-1 medications for misleading direct-to-consumer advertising in a range of forms: claims of equivalence to brand-name Wegovy® or Zepbound®, claims of FDA approval (which compounded products do not have), claims of “tested,” “verified,” or “FDA-registered” that conflated pharmacy registration with drug approval, and aggressive social-media targeting of patient populations on platforms including Instagram and TikTok.

One representative warning letter, to GLP-1 Solution (715883, 09/09/2025), cited the marketing of retatrutide — an investigational product not approved by the FDA — alongside compounded semaglutide and tirzepatide. The letter described retatrutide as an unapproved new drug and a misbranded drug under sections 505(a), 502(f)(1), 301(a), and 301(d) of the FD&C Act.

The September 2025 wave was framed by commentators at the time as “compliance theater,” and many telehealth providers and compounding pharmacies continued advertising. The follow-up February 2026 “intent to take action” press release and the May 2026 ProRx warning letter together established that the September 2025 letters were not the end of agency action but the beginning.

The warning letter, issued by the FDA's Center for Drug Evaluation and Research (CDER), documented inspection findings from a May 12–15, 2025 inspection (Form FDA 483 issued May 15, 2025) and cited multiple violations of section 503B of the FD&C Act and current Good Manufacturing Practice (cGMP) requirements. Specific cited deficiencies included sterile-production conditions inconsistent with cGMP, multiple drug products lacking essential labeling — active and inactive ingredients, strength, dose, administration instructions — and procedural deficiencies in adverse-event reporting.

An earlier July 2025 recall by a different facility (GenoGenix) covered compounded semaglutide, tirzepatide, retatrutide, and a range of GLP-1 / vitamin combination injectables, on the basis of sterility problems documented during inspection.

Together with the May 2026 ProRx warning letter, these facility-level enforcement actions show that the FDA's enforcement focus is not limited to marketing language but extends to the underlying manufacturing operations of 503B outsourcing facilities producing compounded GLP-1s.

In early 2026 the FDA approved an indication expansion for Wegovy (semaglutide) to include metabolic dysfunction-associated steatohepatitis (MASH, formerly NASH), supported by data from the ESSENCE trial program. The approval makes Wegovy the second GLP-1 product to gain a non-weight-management indication after Zepbound's December 2024 OSA approval.

The MASH indication is significant because it brings GLP-1 therapy into the liver-disease space at scale. MASH is a leading driver of liver-related morbidity and mortality in U.S. adults, and prior to this approval, treatment options were limited to lifestyle intervention and one recently approved non-GLP-1 product.

The approval does not apply to compounded semaglutide, which remains a separate, non-FDA-approved product category and is not indicated for MASH or any other clinical indication.