How this works
The math
How the arithmetic works
strength in mg/mL = vial mg ÷ vial mLmL = dose in mg ÷ strength in mg/mLunits = mL × 100 (U-100 only)mg = units ÷ 100 × strength in mg/mLFor example, 20 mg in 2 mL is 10 mg/mL, so 2 mg is 0.2 mL, the 20 mark. All of this assumes the vial holds what its label says, which nothing on this page can confirm.
What the label shows
- Approval
- None. FDA says retatrutide isn’t a component of any FDA-approved drug and hasn’t been found safe and effective for any condition.2
- Compounding
- FDA says it can’t be used in compounding under federal law.2
- Vials sold “for research”
- FDA says these are illegally sold and falsely labeled, of unknown quality, and may be harmful. It has warned companies selling them, and it urges people not to buy them.2
- Dose
- No label sets one. Doses used in clinical trials were given in those trials1, and they aren’t approved doses.
- Dosing errors
- With compounded semaglutide vials, FDA’s reports include people drawing five to 20 times more than the intended dose.3 With no label and an unknown product, there’s even less to check your number against.
- This page
- It does arithmetic on what you type. It doesn’t recommend retatrutide, and it doesn’t say where to get it, how much to use or how long to use it.
Before you act on this
Tell your prescriber if you’re using this or thinking about it, including what the vial says and where it came from. They can help only with what they know.
Took more than you were prescribed? Call your prescriber or pharmacist now. In the US, Poison Help is 1-800-222-1222. Severe vomiting, severe nausea or signs of low blood sugar need urgent care.
Something went wrong, or a vial looks or acts wrong? Tell your prescriber. In the US, you can also report it to FDA’s MedWatch program.2
Always follow your doctor’s or prescriber’s advice and guidance. Talk to your prescriber before changing your dose.
Read this first
Retatrutide isn’t approved for any condition
- FDA says retatrutide can’t be used in compounding under federal law, isn’t a component of any FDA-approved drug and hasn’t been found safe and effective for any condition.2
- FDA has warned companies for illegally selling it, falsely labeled “for research purposes” or “not for human consumption”. It says these products are of unknown quality and may be harmful, and it urges people not to buy them.2
- Lilly, the company developing it, says it hasn’t been approved by FDA or any other regulator, and that products offered to consumers as retatrutide are unlawful and may expose people to serious health risks.4
- There’s no label, no approved dose and no way for you to check what’s in a vial. The arithmetic can be right and the dose still wrong.
- In a clinical trial? Follow your study team, not this page. Using it some other way? Tell your prescriber, so they can look after you knowing it.
For information only, not medical advice. Verify results with your healthcare provider; Onederland accepts no liability for use of these tools.
- Runs on this device. Nothing you type is sent anywhere.
- Every figure names its source, below.
- Education, not medical advice. Your prescriber comes first.
Sources
Sources
- Eli Lilly and Company, news release on retatrutide's phase 3 obesity results, May 21, 2026. investor.lilly.com
- FDA: concerns with unapproved GLP-1 medicines, October 1, 2026. fda.gov
- FDA: dosing errors with compounded injectable semaglutide, July 26, 2024. fda.gov
- Lilly Medical: retatrutide is not available in the consumer market, August 4, 2026. medical.lilly.com
Label sources last checked on October 30, 2026. Onederland summarizes them; your prescriber and the full prescribing information come first.
