Is Compounded Tirzepatide Legal in 2026? What the FDA Actually Says

Between 2023 and early 2025, compounded tirzepatide was everywhere. Telehealth sites sold it by subscription. Med spas advertised it on billboards. The price was a fraction of what Mounjaro or Zepbound cost without insurance.

Most of that was legal at the time, and most of it is not legal now. This page explains what changed, exactly when, and what narrow space is left. It is a description of the rules, not advice about what to take. Any decision about starting, stopping or switching a medicine belongs with a healthcare provider.

What made compounded tirzepatide legal in the first place?

Compounded drugs are not FDA approved. The agency does not review them for safety, effectiveness or quality before they reach patients [3]. They exist under two carve-outs in the Federal Food, Drug, and Cosmetic Act.

Section 503A covers traditional pharmacy compounding. A state-licensed pharmacist or physician can make a drug for an individual patient based on a prescription. But a 503A compounder may not compound, regularly or in inordinate amounts, drugs that are essentially copies of a commercially available drug product [1].

Section 503B covers outsourcing facilities, which are larger operations that can make batches without patient-specific prescriptions. They may not compound from a bulk drug substance unless the substance appears on the 503B bulks list, or unless the drug made from it is on the FDA drug shortage list at the time of compounding, distribution and dispensing [1].

Both of those restrictions have a shortage exception built in. When the FDA added tirzepatide injection to the drug shortage list on December 15, 2022, both gates swung open at once [2]. That is the whole legal explanation for the compounded tirzepatide boom. It was never that compounded tirzepatide had been approved or reviewed. It was that a shortage suspended the rule against making copies.

When exactly did that end?

The FDA determined the tirzepatide shortage was resolved on October 2, 2024, reconsidered after a lawsuit, and issued a formal declaratory order on December 19, 2024 reaffirming the finding [2]. That order set two dates:

• February 18, 2025 — 60 calendar days for state-licensed pharmacies and physicians compounding under section 503A.
• March 19, 2025 — 90 calendar days for outsourcing facilities under section 503B [2].

The dates wobbled slightly under litigation. On February 11, 2025 the FDA said the windows ran to those dates or to the district court’s ruling on the compounders’ preliminary injunction motion, whichever was longer. The court denied the injunction on March 5, 2025, and on March 10 the FDA confirmed the 503A period had ended and the 503B period would close on March 19 as planned [1].

If you want one date to remember, it is March 19, 2025. That is when large-scale commercial production of tirzepatide copies stopped having a legal basis in the United States.

Did the compounders lose in court?

Yes, at every level.

The Outsourcing Facilities Association and FarmaKeio Custom Compounding sued the FDA in the Northern District of Texas on October 7, 2024, arguing the agency should have used notice-and-comment rulemaking and that the shortage determination was arbitrary and capricious [2]. The district court denied a preliminary injunction on March 5, 2025 and ruled for the FDA on the merits on May 7, 2025.

On August 27, 2026 the Fifth Circuit affirmed in an unpublished opinion, No. 25-10600, rejecting both arguments. Eli Lilly is listed in the caption as intervenor-appellee [5]. A companion opinion covering semaglutide and Novo Nordisk followed on September 1, 2026.

What is still legal in 2026?

A narrow strip of ground remains, and in April 2026 the FDA drew the line more clearly than it ever had before.

Patient-specific 503A compounding with a documented clinical difference. If a prescriber determines and documents that a compounded product contains a change producing a significant difference from the commercially available drug for an identified individual patient, the essentially-a-copy restriction does not apply [1]. This is meant for genuine clinical need, such as an ingredient a specific patient cannot tolerate. It is not a paperwork trick, and FDA has been sending warning letters to sellers treating it as one.

Small volumes. In its April 1, 2026 update, the FDA said that at this time it does not intend to take action against a compounder for compounding a drug that is essentially a copy regularly or in inordinate amounts if the compounder fills four or fewer prescriptions of that product in a calendar month [1]. That is an enforcement statement, not a safe harbor written into the statute, and the FDA can change it. But it is the clearest public yardstick the agency has given.

What is not legal: outsourcing facilities using bulk tirzepatide. Tirzepatide appears neither on the 503B bulks list nor on the drug shortage list, so the 503B route is closed [1].

Does adding vitamin B12 change anything?

This is the workaround the market reached for first, and the FDA closed it explicitly.

The April 2026 update explains that FDA also treats a compounded product as essentially a copy when it contains the same active ingredients as two or more commercially available drug products, in the same, similar or easily substitutable strength, and can be given by the same route, again unless a prescriber documents a significant difference [1]. The agency’s worked example is semaglutide combined with vitamin B12, where both components are within 10 percent of the strengths of the respective marketed products. The same reasoning reaches tirzepatide and B12 blends, which telehealth sellers marketed heavily.

There is a separate safety thread here. In March 2026 Eli Lilly published an open letter and told Reuters that its testing of mass-compounded tirzepatide blended with vitamin B12 had found a previously undescribed impurity at high levels [6]. That finding comes from the manufacturer, not from independent FDA testing, and should be weighed accordingly. But it is on the record and worth knowing about.

What does the FDA say about safety?

The agency’s standing consumer page on unapproved GLP-1 drugs is the most useful single document here, and several of its points are specific to tirzepatide [3]:

• Adverse events. As of May 31, 2026, the FDA had received more than 730 adverse event reports associated with compounded tirzepatide, alongside 990 for compounded semaglutide. The agency notes that state-licensed pharmacies that are not outsourcing facilities are not required to report adverse events, so the true count is likely higher, and that many reported events resemble those seen with the approved products.
• Dosing errors. FDA has received reports, some involving hospitalization, that may relate to patients or clinicians miscalculating doses of compounded injectable GLP-1 products, and separate reports involving doses beyond what the approved labels describe.
• Multi-dose vials. Compounded GLP-1 drugs are often dispensed in vials holding several doses. FDA recommends discarding such a vial 28 days after first use, even if medicine remains and even if the compounder’s instructions say otherwise, and using a new sterile needle and syringe for every dose.
• Shipping. FDA has received complaints of compounded GLP-1 drugs arriving warm or with inadequate ice packs, and recommends not using product that arrives improperly refrigerated.
• Fraudulent labels. FDA is aware of compounded semaglutide and tirzepatide carrying false label information, in some cases naming pharmacies that do not exist and in others naming a licensed pharmacy that did not compound the product. One adverse event report involved such a product.

What is the FDA doing about sellers?

Enforcement has come in waves rather than one sweep.

The agency issued a large batch of warning letters to compounders and online sellers in September 2025, a further round to telehealth firms in early 2026, and 25 more on June 16, 2026 aimed at marketing claims for compounded weight-loss drugs [7]. The count for the early-2026 round is not confirmed against an FDA list here; FDA publishes every warning letter in its own searchable database, which is the place to check a specific company. It has also warned companies selling tirzepatide and related peptides labeled “for research purposes” or “not for human consumption” while shipping them to consumers with dosing instructions, and states that retatrutide and cagrilintide cannot lawfully be used in compounding at all [3].

At the border, the FDA maintains a green list import alert, number 66-80, to stop GLP-1 active pharmaceutical ingredients with potential quality concerns from entering the US supply chain, while exempting manufacturers that appear compliant after inspection [3][10].

Eli Lilly has run its own parallel campaign, suing medical spas and wellness clinics from 2023, then a wave of telehealth and compounding operations in April 2025, roughly five weeks after the 503B deadline [8]. Those cases have had mixed outcomes; in one 2026 ruling a court dismissed Lilly’s federal false-advertising claim against a large compounder while allowing state consumer protection claims to proceed.

What comes next?

The open question as of September 14, 2026 is the 503B bulks list. On April 30, 2026 the FDA announced, and on May 1 published in the Federal Register, a proposal to place semaglutide, tirzepatide and liraglutide in the “do not include” category [4][9]. FDA stated it “tentatively finds no basis to conclude that there is a clinical need” for outsourcing facilities to compound using tirzepatide. If finalized in that form, outsourcing facilities would be barred from using tirzepatide bulk substance regardless of any future shortage. The comment period closed June 29, 2026; no final determination had been published as of September 14, 2026.

How do I check a seller before I buy anything?

FDA’s own red-flag list is a good starting point. Be cautious of a company that [3]:

• claims its compounded drug is the same as an FDA-approved drug
• offers prices that seem too good to be true
• ships medicine that looks different from what you have received before, or arrives damaged or without instructions
• does not require screening and a prescription from a licensed prescriber
• has no licensed clinician available to answer questions afterward
• has spelling errors on the label or lists a pharmacy address that does not check out

Beyond that, you can look up whether a pharmacy is licensed in your state, and you can report problems to FDA’s MedWatch program. What you cannot do is verify the contents of a compounded vial yourself. That asymmetry is the whole reason the approval system exists.

Sources

1. FDA clarifies policies for compounders as national GLP-1 supply begins to stabilize — FDA
2. Declaratory Order: Resolution of Shortages of Tirzepatide Injection Products — FDA
3. FDA’s Concerns with Unapproved GLP-1 Drugs Used for Weight Loss — FDA
4. FDA Proposes to Exclude Semaglutide, Tirzepatide and Liraglutide from the 503B Bulks List — FDA
5. Outsourcing Facilities Association v. FDA, No. 25-10600 — US Court of Appeals for the Fifth Circuit
6. Lilly finds impurity in compounded version of its weight-loss drug — Reuters
7. US FDA sends 25 letters to telehealth companies over claims on compounded weight-loss drugs — Reuters
8. Eli Lilly sues compounded Mounjaro, Zepbound providers — CNBC
9. List of Bulk Drug Substances for Which There Is a Clinical Need Under Section 503B — Federal Register
10. Import Alert 66-80 — FDA