Retatrutide Dosage Calculator: Reconstitution and Units

To calculate retatrutide dosage, divide your target dose (mg) by the vial concentration. Concentration = vial mg ÷ diluent mL. For a 10 mg vial with 2 mL BAC water: concentration is 5 mg/mL. A 2 mg dose equals 0.4 mL (40 U-100 units) on a standard insulin syringe.

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Example Retatrutide Dosage Table

Common vial and BAC water combinations with calculated concentration, draw volume, and U-100 syringe units. For education only — verify your vial label before use.

Vial (mg)	BAC water (mL)	Concentration	Dose (mg)	Draw (mL)	U-100 units
10 mg	2 mL	5 mg/mL	1 mg	0.2 mL	20 units
10 mg	2 mL	5 mg/mL	2 mg	0.4 mL	40 units
10 mg	2 mL	5 mg/mL	5 mg	1 mL	100 units
10 mg	5 mL	2 mg/mL	2 mg	1 mL	100 units

How to Calculate Retatrutide Dosage

Three steps convert any vial and BAC water combination into the exact volume to draw on a U-100 insulin syringe.

Step 1 — Calculate concentration (mg/mL)
Divide the total peptide in the vial (mg) by the volume of BAC water you added (mL). For example: a 5 mg Retatrutide vial reconstituted with 2 mL BAC water gives 5 ÷ 2 = 2.5 mg/mL.
Step 2 — Calculate draw volume (mL)
Divide your target dose (mg) by the concentration (mg/mL). For a 0.5 mg dose at 2.5 mg/mL: 0.5 ÷ 2.5 = 0.2 mL. This is the exact volume to draw into the syringe.
Step 3 — Convert to U-100 syringe units
Multiply the draw volume (mL) by 100. For 0.2 mL: 0.2 × 100 = 20 U-100 units. Read this number on the unit markings of a standard insulin syringe.

Dosage Formula

Concentration formula

Concentration (mg/mL) = Vial mg ÷ BAC water mL

Draw volume formula

Draw volume (mL) = Dose (mg) ÷ Concentration (mg/mL)

U-100 syringe units

U-100 units = Draw volume (mL) × 100

These three formulas apply to any Retatrutide vial, regardless of size. U-100 is the standard insulin-syringe scale: 100 units = 1 mL.

Retatrutide Calculator Tool

Enter your vial strength, BAC water volume, and target dose below. The calculator outputs concentration (mg/mL), draw volume (mL), and U-100 units. Educational and research use only.

Example Retatrutide Calculations

Step-by-step worked examples using common vial sizes. Results are for illustrating the math only.

10 mg vial + 2 mL BAC water, 2 mg dose

Vial: 10 mg | BAC water: 2 mL | Target dose: 2 mg
Concentration: 10 ÷ 2 = 5 mg/mL
Draw volume: 2 ÷ 5 = 0.4 mL
U-100 units: 0.4 × 100 = 40 units

10 mg vial + 5 mL BAC water, 2 mg dose

Vial: 10 mg | BAC water: 5 mL | Target dose: 2 mg
Concentration: 10 ÷ 5 = 2 mg/mL
Draw volume: 2 ÷ 2 = 1 mL
U-100 units: 1 × 100 = 100 units

Retatrutide Reconstitution Guide

Retatrutide research vials are typically supplied as lyophilised powder. Reconstitute with bacteriostatic water:

Swab both stoppers with alcohol.
Draw desired BAC water volume; inject slowly along vial wall.
Gently swirl until dissolved. Solution should be clear.
Store refrigerated. Do not freeze.

Retatrutide (LY3437943) is an investigational triple-agonist (GLP-1, GIP, glucagon) and is not an approved therapy. All use is research only.

Frequently Asked Questions

How do I calculate retatrutide draw volume?

Divide your dose (mg) by the concentration (mg/mL). For a 10 mg vial + 2 mL BAC: 5 mg/mL. For a 2 mg dose: 2 ÷ 5 = 0.4 mL = 40 U-100 units.

What are U-100 syringe units?

U-100 is the standard scale for insulin syringes. 100 units = 1.0 mL. That means 10 units = 0.1 mL, 50 units = 0.5 mL. Multiply any draw volume in mL by 100 to get the U-100 units reading.

Do I need to recalculate if I change the amount of BAC water?

Yes. Changing BAC water volume changes the concentration (mg/mL), which changes the draw volume for the same mg dose. Always recalculate using: concentration = vial mg ÷ BAC water mL, then draw volume = dose mg ÷ concentration.

What is retatrutide?

Retatrutide (LY3437943) is an investigational triple receptor agonist (GLP-1, GIP, and glucagon) studied for obesity and metabolic outcomes. It is not an approved therapy in most regions.

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Research review and sources

Reviewed by: PeptideUniv Research Team

Updated: March 26, 2026

This page was reviewed against retatrutide clinical-trial evidence and the compound's investigational status. The math here helps translate vial strength into mL and U-100 units; it does not endorse unapproved use.

Primary references and supporting sources

Triple-Hormone-Receptor Agonist Retatrutide for Obesity - A Phase 2 Trial — Primary phase 2 obesity trial that informs current efficacy and tolerability context.
Triple hormone receptor agonist retatrutide for metabolic dysfunction-associated steatotic liver disease: a randomized phase 2a trial — Phase 2a liver-disease trial that adds human metabolic and safety context.

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For educational and research purposes only. Not medical advice. Consult a licensed healthcare professional before making any medical or health-related decisions.