Example strength in mg/mL (no approved product exists)
Look on the label for a number followed by mg/mL.
If the label gives a total mg and a total mL instead, divide the mg by the mL.
Retatrutide · still being studied
Retatrutide Calculator: Trial Doses in Syringe Units
Retatrutide is still being studied. It is not approved and isn’t available as a prescription medicine. This page shows how syringe math works, using doses from published trials and made-up example strengths. The math: divide the mg by the strength (mg per mL) to get mL, then multiply by 100 to get units on a U-100 syringe.
Last updated
- Status
- Not FDA-approved
- Trial doses
- 2 mg to 12 mg
Still being studied: Retatrutide is not FDA-approved. We're not saying it's available or that anyone should use it.
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Where the trials stand now: Retatrutide Watch
The FDA says it has warned companies that sell retatrutide labeled “for research purposes” or “not for human consumption” along with dosing instructions. The FDA also says that under federal law, retatrutide can’t be used in compounding (when a pharmacy makes its own version of a medicine). It is not part of any approved drug, and it has not been found safe and effective. Read the FDA’s page on these concerns.
How the syringe math works for trial doses
The table only shows math. There is no approved retatrutide label, so there is no official strength, and nothing on this page is an instruction for a product. For reading syringes in general: syringe makers name the thin black line, the top of the plunger, or the plunger tip as the reference for the dose line. We read all three as the edge of the plunger closest to the needle.
U-100 means 100 units fill 1 mL, so 1 unit is 0.01 mL. A trial dose can’t be turned into units until an example strength (mg per mL) is given. To learn more about the math, read units vs mL vs mg and how to read an insulin syringe.
Doses from published trials
Retatrutide trial doses in syringe units
Each row is a dose used in published trials, not an approved label dose. Each column is a made-up example strength to show the math. The columns do not stand for any real retatrutide product.
| Dose | 1 mg/mL | 2 mg/mL | 2.5 mg/mL | 5 mg/mL | 10 mg/mL |
|---|---|---|---|---|---|
| 2 mg | — | 100 | 80 | 40 | 20 |
| 4 mg | — | — | — | 80 | 40 |
| 6 mg | — | — | — | — | 60 |
| 9 mg | — | — | — | — | 90 |
| 12 mg | — | — | — | — | — |
A dash (—) means the amount is more than a 1 mL syringe holds at this strength. The table shows exact units. Whether you can measure an amount depends on the lines on your own syringe. This table is only math, not dose instructions.
How the dose went up in the trials
In the TRIUMPH trials, each dose group started at 2 mg once a week and went up every 4 weeks. The table shows this as research background only. It is not an approved schedule.
| Step | Dose (mg) | What the trials did |
|---|---|---|
| From published trials | ||
| Trial starting dose | 2 | In the TRIUMPH trials, each dose group started at 2 mg once a week. |
| Next step | 4 | The trials raised the dose every 4 weeks. Not an approved schedule. |
| Next step | 6 | The trials raised the dose every 4 weeks. Not an approved schedule. |
| Highest dose, one trial group | 9 | Some trial groups stopped rising at 9 mg. Not an approved schedule. |
| Highest dose, another trial group | 12 | Some trial groups went on to 12 mg. Not an approved schedule. |
Retatrutide facts (still being studied)
Where to inject, what to do after a missed dose, and how to store it, as the label puts it.
Injection sites
This medicine is still being studied and has no product label, so there is no label information about injection sites here.
Missed dose
This medicine is still being studied and has no product label, so there is no missed-dose rule here.
Storage
This medicine is still being studied and has no product label, so there are no storage instructions here.
Common mix-ups with trial math
Trial doses come without a product, so the usual shortcuts from a label don’t work here.
Read the guide to common dosing mistakesQuestions about retatrutide and trial math
Are the retatrutide trial doses a prescription schedule?
No. These are the doses used in published research. They are not an approved label and not a dose recommendation.
Sources: Retatrutide in the TRIUMPH-1 obesity trial, Retatrutide in the TRIUMPH-2 and TRIUMPH-3 trials
How do units work on a U-100 syringe?
U-100 means 100 units fill 1 mL, so 1 unit is 0.01 mL. The number of units in any retatrutide example still depends on the strength (mg per mL).
Sources: Technical Data Sheet – Insulin Syringes, ISO 8537:2016, sterile single-use insulin syringes
Is there an approved retatrutide vial strength?
No. There is no approved retatrutide product label, so there is no standard strength. Any math example here is only a math exercise, not instructions for a product.
Sources: FDA's concerns with unapproved GLP-1 drugs used for weight loss
Why is there no missed-dose or storage section here?
Retatrutide has no approved product label, so this page does not make up label instructions for injection sites, missed doses or storage.
Sources: FDA's concerns with unapproved GLP-1 drugs used for weight loss
Can retatrutide be compounded?
The FDA says that under federal law, retatrutide can’t be used in compounding (when a pharmacy makes its own version of a medicine). It is also not part of any approved drug.
Sources: FDA's concerns with unapproved GLP-1 drugs used for weight loss
What does “research use only” mean here?
The FDA has warned about products labeled “for research purposes” or “not for human consumption” that were sold with dosing instructions. This page does not endorse those products.
Sources: FDA's concerns with unapproved GLP-1 drugs used for weight loss
Sources
The medical and device facts on this page come from these sources. Each entry shows the date we accessed it.
- 01 Retatrutide in the TRIUMPH-1 obesity trial · Eli Lilly and Company, 05/21/2026. Accessed 2026-09-28.
- 02 Retatrutide in the TRIUMPH-2 and TRIUMPH-3 trials · Eli Lilly and Company, 07/23/2026. Accessed 2026-09-28.
- 03 Retatrutide in the TRIUMPH-4 knee osteoarthritis trial · Eli Lilly and Company, 12/11/2025. Accessed 2026-09-28.
- 04 Triple-Hormone-Receptor Agonist Retatrutide for Obesity · The New England Journal of Medicine, 2023;389(6):514-526. Accessed 2026-09-28.
- 05 FDA's concerns with unapproved GLP-1 drugs used for weight loss · U.S. Food and Drug Administration, 10/01/2026. Accessed 2026-10-01.
- 06 Technical Data Sheet – Insulin Syringes · embecta, Rev B, 12/2025. Accessed 2026-09-28.
- 07 Injection technique guide · embecta, ©2025, EMB-05148. Accessed 2026-09-28.
- 08 Getting Started booklet · embecta, ©2023. Accessed 2026-09-28.
- 09 SafetyGlide Insulin Syringes quick reference guide · embecta. Accessed 2026-09-28.
- 10 ISO 8537:2016, sterile single-use insulin syringes · International Organization for Standardization, 2016. Accessed 2026-09-28.
Medically reviewed by Ashley Alexis, NDLast reviewed How we review