How do I calculate a retatrutide dose in syringe units?

You need the vial's concentration first. Divide the vial's mg by the bacteriostatic water in mL to get mg/mL. Divide the dose you were given (in mg) by that concentration to get millilitres, then multiply by 100 for U-100 syringe units. Example: at 10 mg/mL — a 20 mg vial mixed with 2 mL — a 4 mg dose is 0.4 mL, which is 40 units. There is no dose-to-units answer that skips the concentration step.

What is the standard retatrutide dosage?

There isn't one to look up, because there is no FDA-approved retatrutide product. Retatrutide is investigational: its Phase 2 obesity trial tested weekly injections up to 12 mg under close clinical supervision, which is trial-protocol data, not a labelled dose anyone can obtain a prescription for. See our full write-up on the trial evidence for the numbers actually reported. This calculator will not propose a dose because none is established.

Is retatrutide dosed daily or weekly?

In its published clinical trials retatrutide was administered as a once-weekly subcutaneous injection, the same schedule used by approved GLP-1 drugs like semaglutide and tirzepatide. That is a fact about the trial design, not a dosing instruction — there is no approved retatrutide product or label to dose from outside a clinical trial.

How many units is 4 mg of retatrutide?

Only the concentration decides. At 10 mg/mL it is 40 units. At 20 mg/mL the same 4 mg is 20 units. At 5 mg/mL it is 80 units — most of a 1 mL barrel. A dose in mg is not an answer in units until a concentration is attached to it, which is why every field below starts blank.

Is retatrutide safe to dose based on a vendor's suggestion?

No. Retatrutide has no FDA approval, no official labelling, and no dose established through anything but controlled trials. Material sold online as retatrutide is unapproved and its identity, purity and actual content have not been independently verified by anyone — a vendor's suggested number carries no more authority than the arithmetic on this page, which is none at all as a recommendation.

Does this tool tell me how much retatrutide to use?

No, and it cannot honestly do so. It converts a dose figure you already have into syringe units once you tell it the vial size and water added — every field starts blank, nothing is pre-filled, and the vial-strength chips set a container size, not an amount. Any decision about using retatrutide belongs with a licensed clinician, and for most people that decision does not exist because no legitimate prescription pathway does either.

Free tool · Dose → syringe units · Investigational compound

Retatrutide Dosage Calculator

This tool starts from the other end of the reconstitution job: you already have a mixed vial — or a dose figure someone gave you — and want to know what it looks like on a U-100 insulin syringe. It needs the same three numbers as reconstitution — vial size, water added, and the dose — but skips straight to the draw.

If you have not mixed a vial yet, use the retatrutide reconstitution calculator instead, which also solves the water volume backwards from a target strength or unit mark. Both run the same engine and neither one proposes a dose.

The math, before you use the tool

Concentration: mg/mL = vial (mg) ÷ bacteriostatic water (mL)
Volume to draw: mL = dose (mg) ÷ concentration (mg/mL)
Syringe units: units = volume (mL) × 100 [U-100: 100 marks = 1 mL]
Draws per vial: draws = vial (mg) ÷ dose (mg)

Four lines, and the dose you enter never changes them — only the concentration decides how many units a given mg figure turns into. Retatrutide has no approved labelling to check that figure against, which is the part the arithmetic cannot fix.

Read this before you use the calculator

This tool performs unit arithmetic on numbers you enter, and nothing else. It is not medical advice, it does not recommend a dose, and it is not a suggestion that you use any compound. Most of the peptides these calculators get used with are not FDA-approved for the purposes they are marketed for, are sold through a grey market where purity and labelling are not guaranteed, and many are prohibited in tested sport — check yours with the WADA prohibited-status checker. Any decision to use a compound, and any amount, must come from a licensed clinician who knows your history. Retatrutide has no approved product, no approved labelling and no established dose outside controlled clinical trials; material sold under the name is unapproved and its contents are unverified.

Retatrutide vial strengths commonly sold

These fill the vial-size field only. A vial strength is what the container holds — it is not a dose, and listing it is not a recommendation to use Retatrutide.

Peptide in the vialmgThe total peptide mass printed on the vial label.Bacteriostatic water addedmLThe volume you actually drew into the vial.

Dose you are working out

The number you were told to work out — this tool does not propose one. 1 mg = 1000 mcg.

Vial price (optional)USDWhat you paid for the vial. Leave blank to skip cost per dose.

Enter the vial size, the water you added, and the amount you are working out. Every field starts blank on purpose — this tool converts your numbers, it does not supply them.

This is arithmetic, not advice. Every figure above is derived only from the numbers you typed. Nothing here is a recommended dose, a claim that any compound is approved, safe, or effective, or a suggestion that you should use one. Confirm the vial label, the water volume, and the amount with a licensed clinician before you draw anything.

Worked examples

Real numbers, every step shown, so you can check the tool against a pen and paper. These illustrate the arithmetic — the amounts in them are inputs chosen to make the maths legible, not amounts anyone should use.

A dose of 4 mg, at 10 mg/mL (a 20 mg vial in 2 mL)

1Volume: 4 mg ÷ 10 mg/mL = 0.4 mL
2Units: 0.4 mL × 100 = 40 units
3Draws per vial: 20 mg ÷ 4 mg = 5

40 units on a U-100 syringe · 5 draws from the vial

The same 4 mg dose, at 20 mg/mL (the same vial in 1 mL)

1Volume: 4 mg ÷ 20 mg/mL = 0.2 mL
2Units: 0.2 mL × 100 = 20 units
3Draws per vial: unchanged at 5

20 units — half the units for the identical dose, because the concentration doubled

A dose of 8 mg, at 15 mg/mL (a 30 mg vial in 2 mL)

1Volume: 8 mg ÷ 15 mg/mL ≈ 0.533 mL
2Units: 0.533 mL × 100 ≈ 53.3 units
3Draws per vial: 30 mg ÷ 8 mg = 3.75

≈53 units · well under a third of the vial per draw

Frequently asked questions

How do I calculate a retatrutide dose in syringe units?: You need the vial's concentration first. Divide the vial's mg by the bacteriostatic water in mL to get mg/mL. Divide the dose you were given (in mg) by that concentration to get millilitres, then multiply by 100 for U-100 syringe units. Example: at 10 mg/mL — a 20 mg vial mixed with 2 mL — a 4 mg dose is 0.4 mL, which is 40 units. There is no dose-to-units answer that skips the concentration step.
What is the standard retatrutide dosage?: There isn't one to look up, because there is no FDA-approved retatrutide product. Retatrutide is investigational: its Phase 2 obesity trial tested weekly injections up to 12 mg under close clinical supervision, which is trial-protocol data, not a labelled dose anyone can obtain a prescription for. See our full write-up on the trial evidence for the numbers actually reported. This calculator will not propose a dose because none is established.
Is retatrutide dosed daily or weekly?: In its published clinical trials retatrutide was administered as a once-weekly subcutaneous injection, the same schedule used by approved GLP-1 drugs like semaglutide and tirzepatide. That is a fact about the trial design, not a dosing instruction — there is no approved retatrutide product or label to dose from outside a clinical trial.
How many units is 4 mg of retatrutide?: Only the concentration decides. At 10 mg/mL it is 40 units. At 20 mg/mL the same 4 mg is 20 units. At 5 mg/mL it is 80 units — most of a 1 mL barrel. A dose in mg is not an answer in units until a concentration is attached to it, which is why every field below starts blank.
Is retatrutide safe to dose based on a vendor's suggestion?: No. Retatrutide has no FDA approval, no official labelling, and no dose established through anything but controlled trials. Material sold online as retatrutide is unapproved and its identity, purity and actual content have not been independently verified by anyone — a vendor's suggested number carries no more authority than the arithmetic on this page, which is none at all as a recommendation.
Does this tool tell me how much retatrutide to use?: No, and it cannot honestly do so. It converts a dose figure you already have into syringe units once you tell it the vial size and water added — every field starts blank, nothing is pre-filled, and the vial-strength chips set a container size, not an amount. Any decision about using retatrutide belongs with a licensed clinician, and for most people that decision does not exist because no legitimate prescription pathway does either.

The part a calculator cannot answer

A number on a syringe is the easy half. Whether a compound does anything in humans, whether it is legal to buy, and whether it will end a season are the questions worth your time:

Medical disclaimer: This content is for general educational purposes only and is not medical advice, diagnosis, or treatment. Always consult a licensed healthcare professional before starting, stopping, or changing any treatment.

This calculator converts units. It does not account for your health, the specific product in your hand, its actual purity, injection technique, or whether using it is appropriate at all. Nothing on this page states or implies that any compound is FDA-approved, safe, or effective. Talk to a licensed clinician before acting on any figure here.