Is Tirzepatide legal in the US?

Approved, and legal, since 2022

Tirzepatide is one molecule sold under two labels by Eli Lilly: Mounjaro, approved in May 2022 for type 2 diabetes, and Zepbound, approved in November 2023 for chronic weight management and in December 2024 for obstructive sleep apnea in adults with obesity. In February 2026 the FDA approved a Zepbound label expansion for a four-dose KwikPen alongside the existing single-dose vials. Lilly sells directly to patients with a prescription through LillyDirect, in both vials and pens. None of this is in dispute: a prescription from a licensed clinician, dispensed by a licensed pharmacy or by Lilly itself, is the lawful route, and it is the only route this site would point anyone to.

The shortage era — and its end

From late 2022 the FDA listed tirzepatide as in shortage. That designation matters because section 503A and 503B compounders may ordinarily not make “essentially a copy” of an approved drug — unless it is in shortage. For two years, state-licensed 503A pharmacies and federally registered 503B outsourcing facilities compounded tirzepatide copies at scale; compounded GLP-1s reached roughly 30% of US supply at the peak in 2024. On October 2, 2024 the FDA declared the shortage resolved. The Outsourcing Facilities Association sued five days later, and on October 11 — on the FDA’s own motion — the court remanded the decision to the agency for reevaluation. The agency reached the same conclusion a second time: its declaratory order of December 19, 2024 “revokes and replaces” the October decision and again finds the shortage resolved. That order set the wind-down, and it is where the dates come from: enforcement discretion for 503A pharmacies ran 60 days, to February 18, 2025, and for 503B outsourcing facilities 90 days, to March 19, 2025. On March 5, 2025 the district court in Texas denied the association’s motion for a preliminary injunction and its request to stay the determination; the association appealed to the Fifth Circuit five days after that. Note what that ruling was and was not — a decision on preliminary relief, not a final judgment on the merits. The enforcement posture did not wait for the appeal.

2026: the door closes further

In February 2026 the FDA announced it intended to act against non-FDA-approved GLP-1 products, restricting the active ingredients used in mass-marketed compounded semaglutide and tirzepatide and targeting marketing that describes compounded products as “generic” or “equivalent” to the approved versions. More than fifty warning letters had already gone to compounders and telehealth distributors during 2025. On April 30, 2026 the agency went a step further and proposed removing semaglutide, tirzepatide and liraglutide from the 503B bulks list outright, finding no clinical need for outsourcing facilities to compound them from bulk ingredient — and stating explicitly that affordability and insurance access do not constitute clinical need. The comment period closed June 29; a final rule is pending. Lilly, for its part, reported in 2025 that roughly half of the compounded samples it tested were below labeled potency, with bacteria, endotoxin and chemical impurities found in some, and in March 2026 flagged a novel impurity in tirzepatide compounded together with vitamin B12. The FDA has logged hundreds of adverse-event reports tied to compounded tirzepatide and has found counterfeit product labeled with pharmacy names that do not exist.

What is still legal

Two things. First, the approved brands by prescription. Second, a narrow 503A exception: a state-licensed pharmacy may compound tirzepatide for an individual patient when a licensed prescriber documents a clinical need the approved product cannot meet — an allergy to an inactive ingredient is the classic example. Three conditions travel together: a valid individual prescription, a prescriber-documented justification, and dispensing by a verifiable state-licensed 503A pharmacy. The test for what a compounder may not make is “essentially a copy”: same active ingredient, a strength within about 10% of the commercial product, and the same route of administration. Adding vitamin B12, glycine or similar additives and calling the result “personalized” is a theory several telehealth companies have advanced; the FDA has not endorsed it, Lilly has litigated against it, and it should not be treated as a settled workaround.

What is not — and never was

Vials sold “for research use only” sit entirely outside the regulated supply: no prescription, no licensed pharmacy, no verified identity, purity or sterility. Salt forms such as tirzepatide sodium or acetate are not the approved base form and have no compounding pathway at all. Overseas or online sellers shipping without a prescription are selling unapproved drugs, whatever the label says. None of this changed in 2026; the 2026 actions were aimed at the licensed compounders who had been operating in the shortage window.

Why this page sits on a peptide-review site

Tirzepatide is the control case. It shows what the compounding rules look like for a drug that has an approved product: the question is whether a copy is permitted, and the answer in 2026 is mostly no. The seven peptides the FDA’s advisory committee reviewed in July have no approved product at all, so their route runs through a different door — the 503A bulks list — and the committee’s recommendations there are advisory only. Conflating the two is the most common error in coverage of both. Our status board tracks the seven.

Primary sources: FDA Declaratory Order of December 19, 2024 resolving the tirzepatide shortage, which revokes and replaces the October 2, 2024 decision remanded to the agency on October 11, 2024, and which sets the enforcement-discretion end dates of February 18 and March 19, 2025 · FDA statement of February 2026 on non-FDA-approved GLP-1 drugs · FDA proposed rule of April 30, 2026 to exclude semaglutide, tirzepatide and liraglutide from the 503B bulks list (91 FR 23431) · Outsourcing Facilities Association v. FDA, N.D. Tex. No. 4:24-cv-0953-P — preliminary injunction and stay denied March 5, 2025, interlocutory appeal to the Fifth Circuit filed March 10, 2025 · Eli Lilly press release, Feb 23, 2026 (Zepbound KwikPen label expansion) · Eli Lilly open letter, Mar 12, 2026 · section 503A of the FD&C Act and FDA guidance on “essentially a copy”.