Retatrutide Reconstitution Calculator

BAC water, concentration, and syringe units for your retatrutide vial. Every number is shown with the math that produced it.

Mode

Auto picks the cleanest BAC water for you. Manual uses the water you already added.
1

What size is your syringe?

All insulin syringes are U-100, so 100 units equals 1 mL.
2

How much peptide is in your vial?

Check the label on the vial.
3

What is your dose per injection?

Select or enter the amount you want per shot.
Unit:

Step 1 of 2, Reconstitute

For the dose below, add this much BAC water (dose: ,)
,mL

Step 2 of 2, Draw your dose

Pull the syringe to
,units
Concentration
, per mL
Doses per vial
, at this dose

The math, step by step

    Medical Disclaimer. This calculator is for informational purposes only. It does not constitute medical advice and does not recommend doses. Always consult a qualified healthcare provider before using any peptide compound. Never self-medicate. Full disclaimer.

    Reconstitution chart: 10 mg vial

    BAC water addedConcentrationDraw for 1 mg doseDraw for 2 mg dose
    1 mL10,000 mcg/mL10 units20 units
    1.5 mL6,667 mcg/mL15 units30 units
    2 mL5,000 mcg/mL20 units40 units
    2.5 mL4,000 mcg/mL25 units50 units

    Draws are U-100 insulin syringe units (100 units = 1 mL). Formula: dose in mcg ÷ (vial mcg ÷ water mL) × 100. The calculator above handles any other combination.

    About Retatrutide

    Retatrutide is an investigational triple agonist from Eli Lilly that targets the GIP, GLP-1, and glucagon receptors at once. It is NOT approved by the FDA or any other regulator. It is still in phase 3 clinical trials, which means there is no approved product, no official dosing schedule, and no established long-term safety profile. Every retatrutide vial in circulation outside a trial is gray-market material.

    Demand exploded after the phase 2 results published in 2023 reported larger average weight loss than anything approved at the time. In those trials, participants were titrated from low starting doses up to a range of roughly 1 mg to 12 mg once weekly, always under medical supervision and always stepwise. Because no approved schedule exists, this page makes no dosing suggestion at all. The presets above are common round numbers, nothing more.

    Retatrutide has a half-life of roughly 6 days in published trial data, consistent with once-weekly injection. Vials commonly circulate in 5, 10, and 15 mg sizes. The same unit arithmetic applies as with any lyophilized peptide: the water you add sets the concentration, and the concentration sets your draw. Be extra careful here precisely because there is no label to check yourself against.

    Quick facts

    Common questions

    Is there an official retatrutide dose?
    No. Retatrutide is unapproved and still in trials. Anything you read about doses comes from trial protocols or internet communities, neither of which is medical advice for you.
    Why do people start retatrutide low?
    In the published trials, doses were stepped up gradually to manage digestive side effects, the same pattern as the approved GLP-1 drugs. The calculator converts whatever dose you enter; it does not recommend one.
    My vial says 10 mg but my dose is 1 mg. How long will it last?
    Ten doses, if your technique wastes nothing. The doses-per-vial box in the result card computes this for any combination.

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