Peptide Reconstitution Calculator

How does the peptide reconstitution calculator work?

Enter three values: (1) the amount of peptide in the vial (e.g. 5 mg semaglutide), (2) the volume of bacteriostatic water you'll add as diluent (e.g. 2 mL), (3) the target research dose per draw (e.g. 0.25 mg). The calculator computes the final concentration (mg/mL), the exact draw volume (mL), the equivalent units on a U-100 insulin syringe, and the total number of doses available in the reconstituted vial.

What peptides does this calculator work for?

Any lyophilized research peptide reconstituted with bacteriostatic water — semaglutide, tirzepatide, retatrutide, BPC-157, TB-500, ipamorelin, sermorelin, CJC-1295, MOTS-C, GHK-Cu, and others. The math is concentration-based and applies to any peptide whose vial strength (mg) and target dose are known.

Why use a calculator instead of measuring by eye?

Insulin syringes measure in units (U-100 scale: 100 units = 1.0 mL). Most research peptide draws are in the 0.05–0.30 mL range. Converting mg dose → mg/mL concentration → mL draw → units on a syringe is four steps of error-prone arithmetic. A calculator eliminates the math errors that compromise research dose precision.

Is the calculator accurate enough for research protocols?

The math is exact — concentration = peptide mg ÷ diluent mL, and draw volume = target dose ÷ concentration. The accuracy depends on the input precision (correct vial strength, correctly measured diluent volume, accurate target dose). For research-protocol work, always verify the inputs against the compound's published methods.

What's the standard ratio for most peptides?

Two common standards: 2.5 mg/mL (achieved by adding 2 mL bacteriostatic water to a 5 mg vial) and 5 mg/mL (achieved by adding 2 mL water to a 10 mg vial). Most semaglutide research uses 2.5 mg/mL; most tirzepatide, retatrutide, BPC-157, and TB-500 research uses 5 mg/mL. The calculator works for both and for any custom ratio.