Metabolic and GLP-1
Retatrutide
Approved nowhere, and every vial is off supply chain
- What circulates
- 0.25 to 1.5 mg starting, 4 mg maintenance
- What was studied
- Up to 12 mg weekly
- How they compare
- People take less than what studies gave
- As a medicine
- In drug trials, approved nowhereLilly's program is in large trials; no approved version exists at any price.
What it actually is
What it is supposed to do
What people take it for
The dose question
- What circulates
- 0.25 to 1.5 mg starting, 4 mg maintenance
- What was studied
- Up to 12 mg weekly
- Lilly phase 2, about a quarter of body weight at the top dose
People take less than studies gave
Trial results describe a molecule, not a vial. No approved version exists at any price, so there is no reference article to hold yours against.
Reported because it is what people use. Nothing here recommends any amount.
How long it lasts
About 6 days, from the published human trial work on the shot given under the skin. That is why the dosing is weekly.
Route studied
Under the skin, once a week, in company trials
Route used
Under the skin, once a week, from unapproved vials
How to check you have the right molecule
No rival molecule is sold under this name, so the check is on the certificate that comes with the vial, and it is the content line rather than the purity line. Purity says what share of the powder is the right substance. Content says how many milligrams are actually in there, and the two can disagree badly: the only public vial test, which the seller paid for, reported 99.76% purity on a 10 mg vial but measured 12.05 mg of drug in it, which is 121% of what the label claimed, on a sample the shop supplied rather than one bought at retail, with no sterility or contamination screen run. No independent published chemical test of grey market retatrutide exists at all. On the nearest similar drug, semaglutide, three vials bought online came back at 7.70% to 14.37% pure against a claimed 99%.
Walked through on two real certificates in how to read a certificate of analysis.
What people get wrong
What is known about harm
The arithmetic
Retatrutide is sold in 5 mg, 7 mg, 10 mg, 12 mg, 15 mg, 20 mg, 24 mg, 30 mg, 50 mg and 60 mg vials. Mixing errors put people an order of magnitude off using a perfectly good vial, and the arithmetic is simple enough to check yourself.
| Vial | Water | Concentration | In 10 units |
|---|---|---|---|
| 5 mg | 1 mL | 5 mg/mL | 500 mcg |
| 5 mg | 2 mL | 2.5 mg/mL | 250 mcg |
| 5 mg | 3 mL | 1.67 mg/mL | 167 mcg |
| 7 mg | 1 mL | 7 mg/mL | 700 mcg |
| 7 mg | 2 mL | 3.5 mg/mL | 350 mcg |
| 7 mg | 3 mL | 2.33 mg/mL | 233 mcg |
| 10 mg | 1 mL | 10 mg/mL | 1 mg |
| 10 mg | 2 mL | 5 mg/mL | 500 mcg |
| 10 mg | 3 mL | 3.33 mg/mL | 333 mcg |
| 12 mg | 1 mL | 12 mg/mL | 1.2 mg |
| 12 mg | 2 mL | 6 mg/mL | 600 mcg |
| 12 mg | 3 mL | 4 mg/mL | 400 mcg |
| 15 mg | 1 mL | 15 mg/mL | 1.5 mg |
| 15 mg | 2 mL | 7.5 mg/mL | 750 mcg |
| 15 mg | 3 mL | 5 mg/mL | 500 mcg |
| 20 mg | 1 mL | 20 mg/mL | 2 mg |
| 20 mg | 2 mL | 10 mg/mL | 1 mg |
| 20 mg | 3 mL | 6.67 mg/mL | 667 mcg |
| 24 mg | 1 mL | 24 mg/mL | 2.4 mg |
| 24 mg | 2 mL | 12 mg/mL | 1.2 mg |
| 24 mg | 3 mL | 8 mg/mL | 800 mcg |
| 30 mg | 1 mL | 30 mg/mL | 3 mg |
| 30 mg | 2 mL | 15 mg/mL | 1.5 mg |
| 30 mg | 3 mL | 10 mg/mL | 1 mg |
| 50 mg | 1 mL | 50 mg/mL | 5 mg |
| 50 mg | 2 mL | 25 mg/mL | 2.5 mg |
| 50 mg | 3 mL | 16.67 mg/mL | 1.67 mg |
| 60 mg | 1 mL | 60 mg/mL | 6 mg |
| 60 mg | 2 mL | 30 mg/mL | 3 mg |
| 60 mg | 3 mL | 20 mg/mL | 2 mg |
10 units is 0.1 mL on a U-100 insulin syringe, whatever is in it. For any other combination, or to see the arithmetic worked out, use the calculator.
To run your own numbers, use the reconstitution calculator.
Set against
Others in Metabolic and GLP-1
Registrations not to cite
- NCT07467447
Effect of LY3437943 Versus Placebo in Participants Who Have Obesity or Are Overweight
The registry lists it as recruiting, Hudson Biotech, first posted 12 March 2026.
A registry clone. Copies a real Eli Lilly retatrutide trial under the sponsor Hudson Biotech at a single hospital in Shenzhen.
Registry details are from ClinicalTrials.gov, the United States government trial registry, as it read on 14 September 2026.
The full entry
Everything on this page is a summary. Read the full entry on Retatrutide for the citations, the studies, and the reasoning behind every figure above.
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