Retatrutide Dosage Calculator: Complete Guide to Dosing in Units

Understanding Retatrutide Dosage Calculations

Retatrutide dosing requires a simple calculation: you need to know the concentration of your reconstituted solution, the dose you want to take, and how to measure that dose on an insulin syringe. The standard reconstitution ratio used in the TRIUMPH clinical trials is 2 mL of bacteriostatic water per 10 mg of retatrutide powder, which produces a concentration of 5 mg/mL. Once you know the concentration, converting between milligrams and syringe units is straightforward.

Standard Conversion Table

At a concentration of 5 mg/mL (10 mg in 2 mL water): 2 mg dose = 0.4 mL = 40 units on a 100-unit insulin syringe. 4 mg dose = 0.8 mL = 80 units. For a 20 mg vial reconstituted with 4 mL water (same 5 mg/mL concentration): 2 mg = 0.4 mL = 40 units. For a 5 mg vial reconstituted with 1 mL water (still 5 mg/mL): 2 mg = 0.4 mL = 40 units. Maintaining the same concentration across all vial sizes simplifies dosing.

Titration Schedule with Exact Measurements

The TRIUMPH protocol calls for 2 mg weekly for Weeks 1-4. At 5 mg/mL concentration, that is 40 units weekly. Weeks 5-8: 4 mg weekly = 80 units. Weeks 9-12: 8 mg weekly. At 5 mg/mL, 8 mg requires 1.6 mL, which is 160 units — more than one full 100-unit syringe. This requires two injections: 100 units (5 mg) plus 60 units (3 mg) for a total of 8 mg. From Week 13 onward: 12 mg weekly = 2.4 mL = 240 units — three injections of 100 units (5 mg each) plus 40 units (2 mg).

Common Ratio Variations

Some users prefer a more concentrated solution to reduce injection volume. A 10 mg vial reconstituted with 1 mL of bacteriostatic water produces a 10 mg/mL concentration. At this ratio, 2 mg = 20 units, 4 mg = 40 units, 8 mg = 80 units, and 12 mg = 120 units (one full syringe plus 20 units). The trade-off is that higher concentrations increase the viscosity of the solution, which can make drawing and injecting slightly more difficult.

Dosage Calculator for Weight Loss

The therapeutic dose range for retatrutide is 2 mg to 12 mg weekly. Lower doses produce less weight loss but also fewer side effects. The Phase 2 data showed approximately 15-17% weight loss on 4 mg, 20-22% on 8 mg, and 24.2% on 12 mg at 48 weeks. The Phase 3 TRIUMPH-1 data showed 28.3% on 12 mg at 80 weeks. Starting at the lowest dose and titrating up on schedule gives your body time to adapt while you discover which dose level produces the best balance of results and tolerability for you.