Quick answer: compounded tirzepatide is a pharmacy-made version of the drug in Mounjaro and Zepbound. It is not FDA-approved.[2] It became widespread during the 2022 to 2024 shortage, but the FDA declared the shortage over on December 19, 2024, and the grace periods for compounders ended in March 2025.[1] Since then, pharmacies generally cannot make copies of the brand products, and a federal appeals court upheld the FDA’s decision in August 2026.[3]
This guide explains what compounding is, the rules for the two types of compounders, the FDA’s safety warnings, and how compounded products differ from Zepbound. For the approved drug, see our tirzepatide profile.
What is compounded tirzepatide?
Compounding is when a pharmacist or doctor combines, mixes or alters ingredients to make a medicine.[3] Compounding is legal for patients whose needs cannot be met by an FDA-approved drug, such as someone allergic to an ingredient.[2] Federal law sets limits:
- Compounders cannot regularly make copies of approved drugs that are commercially available.[1][3]
- Those limits relax during a shortage. When a drug is on the FDA’s shortage list, pharmacies that meet certain conditions can make copies to fill the gap.[3]
Mounjaro was added to the shortage list in December 2022 and Zepbound in April 2024. During those periods, compounded tirzepatide became widely available.[3]
503A pharmacies vs 503B outsourcing facilities
There are two main types of compounders, named after sections of federal law.[1]
| 503A pharmacies | 503B outsourcing facilities | |
|---|---|---|
| What they are | State-licensed pharmacies and physicians[1] | Outsourcing facilities registered with the FDA, which can make larger batches |
| Prescription needed | Yes, for an individual patient[1] | Not always patient-specific |
| Limit on copies | Cannot make “essentially copies” of commercially available drugs regularly or in inordinate amounts[1] | Cannot make drugs essentially copying an approved drug unless it is on the shortage list[1] |
| Tirzepatide grace period ended | March 5, 2025[1] | March 19, 2025[1] |
| Tirzepatide status now | Copies generally not allowed[1] | Not allowed: tirzepatide is not on the shortage list or the 503B bulks list[1] |
What counts as “essentially a copy”? The FDA treats a compounded drug as a copy if it has the same active ingredient as a commercial product, in the same, similar or easily substitutable strength, and can be given by the same route. The exception is when a prescriber determines and documents a significant difference for a specific patient.[1] The FDA also says it does not generally intend to act against a 503A compounder that fills four or fewer prescriptions of such a product in a calendar month.[1]
How the shortage ended
| Date | What happened |
|---|---|
| October 2, 2024 | FDA determines the tirzepatide shortage is resolved[1] |
| October 22, 2024 | After a lawsuit by compounders, FDA says it will reevaluate[1][3] |
| December 19, 2024 | FDA again finds the shortage resolved; sets grace periods to February 18 (503A) and March 19, 2025 (503B)[1] |
| February 11, 2025 | FDA extends the deadlines to the date of the court’s injunction ruling, if later[1] |
| March 5, 2025 | Court denies the compounders’ preliminary injunction; 503A discretion ends[1] |
| March 19, 2025 | 503B discretion ends[1] |
| August 27, 2026 | Fifth Circuit affirms the ruling for the FDA and Lilly[3] |
The appeals court found that the FDA reasonably relied on Lilly’s supply data, which outweighed the compounders’ evidence such as undated wholesaler screenshots and patient surveys.[3] On April 1, 2026, the FDA reissued its reminder that tirzepatide is not on the shortage list or the 503B bulks list.[1]
For what this means for generics, see generic tirzepatide.
FDA warnings and adverse event reports
The FDA’s GLP-1 safety page, last updated October 1, 2026, raises several concerns:[2]
- Adverse events: more than 730 reports linked to compounded tirzepatide as of May 31, 2026. The FDA says underreporting is likely because state-licensed pharmacies are not required to report adverse events to the FDA.[2]
- Dosing errors: the FDA has received reports, some involving hospitalization, of patients and clinicians measuring or calculating doses incorrectly with compounded semaglutide. The same measuring steps apply to any compounded vial.[2]
- Fake and fraudulent products: some products list pharmacies that do not exist, or licensed pharmacies that did not make them.[2]
- “Research” products: tirzepatide sold as “for research purposes” or “not for human consumption” but with dosing instructions is illegally marketed for human use.[2]
- Ingredient imports: the FDA set up an import alert to stop GLP-1 active ingredients with potential quality problems from entering the US.[2]
How compounded tirzepatide differs from Zepbound
| Zepbound (FDA-approved) | Compounded tirzepatide | |
|---|---|---|
| FDA review | Approved after clinical trials[4] | Not reviewed for safety, effectiveness or quality before sale[2] |
| Evidence | SURMOUNT trial program[4] | No clinical trials of the specific product |
| Doses | Fixed strengths, 2.5 to 15 mg[4] | Varies by pharmacy; often drawn from a vial |
| Ingredients | Listed in the label[4] | May include added ingredients, such as vitamins |
| Labeling and warnings | Full prescribing information and Medication Guide[4] | Varies |
| Legal status in 2026 | Available by prescription[4] | Copies generally not permitted since March 2025[1] |
The FDA’s guidance uses a compounded semaglutide product with added vitamin B12 as an example of something that can still count as a copy.[1] Our guide to compounded GLP-1 additives covers these mixtures.
If you have been using compounded tirzepatide
Many people started compounded tirzepatide during the shortage and now need a plan. Points to raise with your prescriber:
- Confirm your current dose in milligrams. Compounded vials come in many concentrations, and doses are sometimes written in “units” on an insulin syringe rather than in milligrams. The FDA has received reports of people and clinicians measuring or calculating the wrong dose of compounded GLP-1 drugs.[2] Knowing your actual weekly dose in mg makes any switch safer.
- Ask how to move to an approved product. Zepbound and Mounjaro come in fixed strengths of 2.5, 5, 7.5, 10, 12.5 and 15 mg.[4] There is no official conversion from a compounded product, so your prescriber may restart you at a lower strength and step up as tolerated.
- Do not combine products. The Zepbound label says not to use it with other tirzepatide-containing products or any GLP-1 drug.[4]
- Check where your medicine comes from. The FDA warns that some products name pharmacies that did not make them, or that do not exist.[2] Your state board of pharmacy can confirm whether a pharmacy is licensed.
- Report side effects. Because many compounders are not required to report adverse events, patient and clinician reports to MedWatch are an important safety signal.[2]
Approved alternatives
Since the shortage ended, Lilly sells Zepbound single-dose vials and a four-dose KwikPen directly to self-pay patients through LillyDirect, starting at $299 a month for the 2.5 mg dose.[5] Insurance coverage depends on whether tirzepatide is prescribed for diabetes, weight or sleep apnea; see Zepbound vs Mounjaro.
Whatever product is used, the label dose schedule starts at 2.5 mg weekly and rises in 2.5 mg steps at least 4 weeks apart.[4] See the tirzepatide dosage chart, and talk with your prescriber before switching between products.
