PeptulatorReconstitution and dosing maths

Retatrutide dosage calculator

Retatrutide vials are usually 10 mg or 20 mg. Enter the vial strength, the water you added and your dose to get the unit mark to draw to.

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Dose to units at the usual vial and water

DoseU-100 unitsDrawDoses per vialVial lasts
1 mg20 units0.2 mL1070 days
2 mg40 units0.4 mL535 days
3 mg60 units0.6 mL321 days
4 mg80 units0.8 mL214 days
6 mg120 units1.2 mL17 days
8 mg160 units1.6 mL17 days
10 mg200 units2 mL17 days
12 mg240 units2.4 mLneeds a bigger vial-

10 mg vial in 2 mL of bacteriostatic water (5 mg/mL), U-100 insulin syringe, once weekly.

About Retatrutide

Retatrutide is a triple agonist, acting on the GLP-1, GIP and glucagon receptors. It is an investigational compound. It has not been approved by any regulator, and material sold online is sold for laboratory research use rather than for human use.

Reported protocols generally start low and titrate every four weeks, which is why the table runs from 1 mg up to 12 mg. Where your own dose should sit is a question for a clinician, not for a calculator.

The same 10 mg vial at other water volumes

If the draw is awkward to read, change the water, not the dose. The dose stays the same; only the mark moves.

VialBAC waterConcentrationDrawU-100 unitsDoses/vial
10 mg1 mL10 mg/mL0.2 mL20 units5
10 mg2 mL5 mg/mL0.4 mL40 units5
10 mg3 mL3.33 mg/mL0.6 mL60 units5
15 mg1 mL15 mg/mL0.133 mL13.3 units7
15 mg2 mL7.5 mg/mL0.267 mL26.7 units7
15 mg3 mL5 mg/mL0.4 mL40 units7

All rows above assume a 2 mg dose and a standard U-100 insulin syringe, where 100 units = 1 mL.

How long it lasts in the body

The half-life of Retatrutide is about 6 days. That is the time for the amount in your blood to halve, so after one half-life you are at 50 percent of the peak, after two you are at 25 percent, and after four you are at roughly 6 percent. This is why a weekly compound still has meaningful levels present when the next dose lands, and why levels build over the first several weeks before they settle.

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Common questions

How many units is 2 mg of Retatrutide?
It depends entirely on how much water you added. In a 10 mg vial reconstituted with 2 mL, the concentration is 5 mg/mL, so 2 mg is 0.4 mL, which is 40 units on a U-100 insulin syringe. In the same vial with 1 mL of water it is 20 units, and with 3 mL it is 60 units.
How much bacteriostatic water for a 10 mg Retatrutide vial?
2 mL is the usual choice. It gives 5 mg/mL, which puts the commonly reported range of 0.5 mg to 12 mg between roughly 10 and 240 units. Aim for a draw between about 10 and 50 units, where the barrel is easiest to read, and add or remove water to get there.
How many doses are in a 10 mg vial?
Divide 10 by your dose. At 2 mg that is 5 doses, which at once weekly is 35 days.
Is retatrutide approved?
No. It is investigational and not approved for human use. Material sold online is sold for research use only.
IndependentThis site does not sell peptides and is not owned by a vendor.
The maths is openThe formula is on every page and in the methodology. The code is one file with an automated test suite, run before each deploy.
How it earnsAffiliate links on one marked page, never inside the calculator.
ReviewedDose ranges and half-lives checked 3 September 2026.

Buying Retatrutide?

The where to buy page lists the vendors this site uses and what to check first. Peptide Bureau keeps the ranked scorecard.

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Tools

Before you use these numbers This is a unit-conversion tool. It turns a vial strength and a water volume into a concentration, a draw volume and a syringe mark. It does not tell you what to take, whether to take it, or whether a compound is safe for you. Most compounds listed are sold for laboratory research and are not approved for human use. Nothing here is medical advice. Dosing decisions belong with a licensed clinician who knows your history. Always check the strength printed on your own vial rather than trusting a preset.