Enter your retatrutide vial size and the volume of bacteriostatic water you are adding. The calculator returns the concentration in mcg/ml and the exact units to draw on a U-100 insulin syringe. It handles the common 10mg and 20mg vials at every titration step.
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Results
Concentration
5000 mcg/ml
5 mg/ml
Volume to inject
0.4 ml
per dose
Units on insulin syringe (U-100)
40 units
on a standard 100-unit insulin syringe
Doses per vial
5 doses
at 2000 mcg each
How this is calculated
10mg × 1,000 = 10000 mcg total
10000 ÷ 2ml = 5000 mcg/ml
2000 mcg ÷ 5000 = 0.4 ml
0.4 ml × 100 = 40 units
Disclaimer: This calculator is provided for informational purposes only. Always verify results against your specific vial labelling before use. Peptidy does not provide medical advice — consult a qualified healthcare professional before beginning or modifying any protocol. Use of research peptides may be subject to legal restrictions in your jurisdiction.
Retatrutide is a triple GIP/GLP-1/glucagon receptor agonist dosed once weekly and titrated upward over time. It is one of the more potent compounds in the category, so getting the reconstitution concentration right is important for accurate weekly dosing.
The step pattern used in the Phase 2 trials, escalated every four weeks. Many people hold at a lower step rather than reaching the 12mg maximum.
| Starting dose | 1–2 mg (1,000–2,000 mcg) once weekly |
| Mid titration | 4–8 mg (4,000–8,000 mcg) once weekly |
| Higher dose | up to 12 mg (12,000 mcg) once weekly |
Worked example: 10mg vial + 2ml BAC water, 2mg dose
2ml is a common choice, giving 5,000 mcg/ml. A 2mg dose is then 0.4ml = 40 units. If you are dosing at the higher end, add less water to keep the injection volume manageable.
With a 10mg vial reconstituted in 2ml (5,000 mcg/ml): 2,000 ÷ 5,000 = 0.4ml = 40 units. With a 20mg vial in 2ml (10,000 mcg/ml): 2,000 ÷ 10,000 = 0.2ml = 20 units.
Semaglutide targets one receptor (GLP-1), tirzepatide two (GIP and GLP-1), and retatrutide three (GIP, GLP-1, and glucagon). The reconstitution maths is identical for all three — only the vial sizes, potency, and dosing schedules differ.
Refrigerate at 2–8°C, protect it from light, and label the vial with the date. Reconstituted retatrutide in bacteriostatic water is commonly used within 4–8 weeks. Do not freeze it.
Store your vial concentration, log every dose against it, and never lose track of what you injected or when.