FDA: Retatrutide and Cagrilintide Can’t Be Compounded. What That Means for Telehealth Shoppers
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The FDA’s page “Concerns with Unapproved GLP-1 Drugs Used for Weight Loss,” current as of October 1, 2026, states that retatrutide and cagrilintide cannot be used in compounding under federal law. Neither is a component of an FDA-approved drug. So no “compounded retatrutide” or “compounded cagrilintide” is lawful today.
Both remain investigational as of October 15, 2026: Lilly plans a retatrutide filing in early 2027, and the FDA has not ruled on CagriSema.
Two numbers frame this update: 0 lawful compounding routes for retatrutide or cagrilintide, and 28 days, the most the FDA says you should use a multi-dose compounded GLP-1 vial after first use. Both come from one FDA page updated October 1, 2026.
What exactly did the FDA say about retatrutide and cagrilintide?
The FDA says retatrutide and cagrilintide “cannot be used in compounding under federal law.” It adds that they “are not components of FDA-approved drugs and have not been found safe and effective for any condition.”
It has warned telehealth companies marketing retatrutide, API distributors selling it to compounders and outsourcing facilities repackaging it. It has also warned sellers of semaglutide, tirzepatide, retatrutide, survodutide or mazdutide labeled “for research purposes” or “not for human consumption” but shipped to consumers with dosing instructions.
Where do retatrutide and CagriSema actually stand?
- Retatrutide (Eli Lilly). Lilly’s August 5, 2026 second-quarter release says it plans to submit a Biologics License Application to the FDA in the first quarter of 2027. Its Phase 3 obesity study, NCT05929066, is listed as completed. A planned filing is not an approval. Trial results are in our TRIUMPH-1 explainer.
- CagriSema (Novo Nordisk; cagrilintide plus semaglutide). Novo’s August 4, 2026 report lists a “CagriSema US decision” among its anticipated 2026 milestones, timing “based on current assessment, which may change.” We found no FDA decision as of October 15, 2026.
Why does this matter if you shop for peptides online?
Our retatrutide dosage chart and cagrilintide dosage chart describe doses used in clinical trials, as does our cagrilintide and BPC-157 stack article. They help you read research, not shop.
If a program offers “compounded retatrutide” or “compounded cagrilintide,” it is offering something the FDA says federal law does not allow. A “research use” vial with dosing instructions fits the pattern the FDA has warned about, and trial results say nothing about the purity of a vial from an unknown source. Treat either name at checkout as a reason to leave.
What else is on the FDA’s October 2026 page?
The FDA says compounded drugs should only be used when an FDA-approved drug can’t meet your medical needs.
The 28-day rule. Contamination risk rises after 28 days, so discard a multi-dose vial within 28 days of first use, even if medicine is left and even if the compounder’s instructions allow longer. Use a new, sterile needle and syringe for every dose.
Salt forms. Semaglutide sodium and semaglutide acetate are different active ingredients from the one in approved drugs. The FDA knows of no lawful basis for compounding them. See our salt-form explainer.
Warm shipments. Don’t use an injectable GLP-1 that arrives warm or without enough refrigeration.
Import alert 66-80. A “green list” alert to stop GLP-1 APIs with potential quality concerns at the border. It adds no new limits on lawful compounding.
Adverse events. As of May 31, 2026, the FDA had 990 reports linked to compounded semaglutide and more than 730 linked to compounded tirzepatide. Federal law doesn’t require state-licensed pharmacies that aren’t outsourcing facilities to report, so the counts are likely low, and a report doesn’t prove cause. You can file your own report through MedWatch.
FDA also reports adverse events with compounded semaglutide that may be related to dosing errors, some involving hospitalization. Vial math helps you avoid them.
How many doses can one vial give you before day 28?
Count first use as day 0. Weekly, you inject on days 0, 7, 14 and 21; a fifth dose would land on day 28, the limit. Plan on 4 doses per vial. Dose volume is the dose in mg divided by the concentration in mg/mL. On a U-100 syringe, 1 mL is 100 units.
| Example label | Total in vial | Weekly dose | Volume per dose | Units (U-100 syringe) | Doses the vial holds | Doses used by day 21 | Left at day 28 |
|---|---|---|---|---|---|---|---|
| Semaglutide 2.5 mg/mL, 1 mL | 2.5 mg | 0.25 mg | 0.10 mL | 10 units | 10 | 4 | 0.6 mL (1.5 mg) |
| Semaglutide 2.5 mg/mL, 2 mL | 5 mg | 0.5 mg | 0.20 mL | 20 units | 10 | 4 | 1.2 mL (3 mg) |
| Semaglutide 2.5 mg/mL, 2 mL | 5 mg | 1 mg | 0.40 mL | 40 units | 5 | 4 | 0.4 mL (1 mg) |
| Tirzepatide 10 mg/mL, 2 mL | 20 mg | 2.5 mg | 0.25 mL | 25 units | 8 | 4 | 1.0 mL (10 mg) |
| Tirzepatide 10 mg/mL, 2 mL | 20 mg | 5 mg | 0.50 mL | 50 units | 4 | 4 | 0 mL |
| Tirzepatide 10 mg/mL, 4 mL | 40 mg | 5 mg | 0.50 mL | 50 units | 8 | 4 | 2.0 mL (20 mg) |
A vial fits the 28-day rule only when it holds about four of your weekly doses. One sized for eight or ten means half or more is discarded.
What this means for you: will your vial last to day 28?
Example 1: a starting dose. Label: semaglutide 2.5 mg/mL, 1 mL. Dose: 0.25 mg. That is 0.25 ÷ 2.5 = 0.1 mL, or 10 units. The vial holds 10 doses; you use 4 by day 21 and discard 0.6 mL (1.5 mg). If your instructions say to stretch it over 10 weeks, ask why.
Example 2: a dose increase mid-vial. Label: tirzepatide 10 mg/mL, 2 mL (20 mg). You take 2.5 mg on days 0 and 7 (0.25 mL each), then 5 mg on days 14 and 21 (0.5 mL each). That uses 0.25 + 0.25 + 0.5 + 0.5 = 1.5 mL, leaving 0.5 mL (5 mg) to discard. Review your schedule against the tirzepatide dosage chart with your prescriber.
Example 3: mg versus mL. At 2.5 mg/mL, a 0.25 mg dose is 0.1 mL. Draw 0.25 mL by mistake and you get 0.625 mg, 2.5 times the dose. Get your dose in writing in mg, mL and units.
Self-check: weekly volume × 4. If the vial holds far more, ask about a smaller vial. Never change your dose on your own.
One honest note: compounded tirzepatide and semaglutide are not FDA-approved. They are not generics, and they are not the same as Mounjaro, Zepbound, Ozempic or Wegovy. No program can promise you a set amount of weight loss.
What should you ask a telehealth program before you pay?
The FDA’s red flags include claims that a compounded drug is the same as an approved one, prices that seem too good to be true, no screening or prescription by a licensed doctor, no doctor to answer questions afterward, and labels with spelling errors or wrong pharmacy addresses. Then ask:
- Which state-licensed pharmacy fills my prescription, and what is its address?
- What concentration and vial size will I get at each dose, and how many weeks should each vial last?
- Is the active ingredient semaglutide base, or a salt form such as sodium or acetate?
- Do you sell retatrutide, cagrilintide or “research” peptides?
- How is the shipment kept cold, and what if it arrives warm?
- Will a licensed clinician answer dosing questions after delivery?
Does the Empower warning letter change any of this?
Not directly. FDA warning letter 738238 to Empower Pharmacy (dated September 18, posted September 22, 2026) concerns compounded tirzepatide and semaglutide combinations and sterile conditions, not retatrutide or cagrilintide. See our Empower profile and the news ledger.
Frequently asked questions
Can a pharmacy legally compound retatrutide for me?
No. The FDA’s page, current as of October 1, 2026, says retatrutide and cagrilintide cannot be used in compounding under federal law and are not components of any FDA-approved drug. Retatrutide is still investigational; Lilly plans to file for approval in the first quarter of 2027.
Is CagriSema approved yet?
No. As of October 15, 2026, we found no FDA decision on CagriSema, the cagrilintide and semaglutide combination from Novo Nordisk. Novo’s August 4, 2026 report lists a US decision among its anticipated 2026 milestones and says that timing may change. Cagrilintide is not part of any approved product.
Why do I have to throw out a vial after 28 days if medicine is left?
The FDA says the risk of contamination rises after 28 days of use for vials holding multiple doses of a sterile drug. It recommends discarding the vial within 28 days of first use, even if medicine remains and even if the compounder’s instructions allow longer. On a weekly schedule, that means about 4 doses per vial.
Is semaglutide sodium or acetate the same as semaglutide?
No. The FDA says semaglutide sodium and semaglutide acetate are different active ingredients from the one used in approved semaglutide drugs. It lacks data on whether they act the same way and knows of no lawful basis for compounding them. Ask which form your pharmacy uses.
How many adverse events has the FDA logged for compounded GLP-1s?
As of May 31, 2026, the FDA had received 990 adverse event reports tied to compounded semaglutide and more than 730 tied to compounded tirzepatide. The FDA says these are likely underreported, and a report alone does not show the drug caused the event.
Sources
- U.S. FDA. FDA’s Concerns with Unapproved GLP-1 Drugs Used for Weight Loss. Current as of October 1, 2026; read October 15, 2026.
- U.S. FDA. Import Alert 66-80 (GLP-1 bulk drug substances). Published date shown: October 9, 2026.
- Eli Lilly and Company. Second-quarter 2026 results release (SEC Form 8-K exhibit). August 5, 2026.
- Novo Nordisk. Q2 2026 financial report (SEC Form 6-K). August 4, 2026.
- ClinicalTrials.gov. NCT05929066, Phase 3 retatrutide study. Last update posted August 21, 2026.
- U.S. FDA. Warning letter 738238, Empower Pharmacy. Dated September 18, 2026; posted September 22, 2026.
- U.S. FDA. MedWatch online adverse event reporting. Read October 15, 2026.