Peptide reconstitution calculator

How to use this calculator

Start with the mg per vial — typically printed on the vial label (e.g. 5 mg or 10 mg). Then enter how many milliliters of bacteriostatic water you injected during reconstitution. Finally, type your target dose in milligrams.

Concentration explained

Concentration is simply mg ÷ mL. A vial with 10 mg of peptide reconstituted with 2 mL of BAC water yields 5 mg/mL. Higher concentrations mean smaller injection volumes but less margin for measurement error.

U-100 vs U-40 syringes

U-100 syringes have 100 units per mL — common in the US and most of Europe. U-40 syringes have 40 units per mL and are used in some veterinary and regional contexts. Always match the syringe scale to the calculator setting; mixing them up is the #1 source of dosing errors.

Common pitfalls

• Mixing up U-40 and U-100 scales — always double-check the syringe marking.
• Using regular sterile water instead of bacteriostatic water for multi-use vials.
• Reconstituting with too little BAC water → concentration too high → tiny doses become imprecise.
• Forgetting that your stored, reconstituted vial has a limited shelf life.

FAQ

What is peptide reconstitution?

Reconstitution is the process of mixing a lyophilized (freeze-dried) peptide with bacteriostatic water to create an injectable solution at a known concentration.

What size syringe should I use?

For sub-cutaneous peptide injections, a 0.5 mL or 1.0 mL insulin syringe marked in U-100 units is standard. U-40 is used in some regions.

Why does the calculator round to half units?

Most insulin syringes are graduated in 1-unit (or sometimes 2-unit) increments. We round to the nearest half-unit so the printed result is practical to draw.

This page is for informational purposes only and is not medical advice. Always verify dosing with a licensed clinician.