Peptide Reconstitution Calculator

Draw the chosen volume of bacteriostatic water (0.9% benzyl alcohol) into a sterile syringe, insert the needle at an angle and slowly release the water down the inside wall of the vial — never directly onto the powder. Gently swirl until fully dissolved. Never shake vigorously as agitation can denature peptide bonds. Store the reconstituted vial at 2–8 °C once dissolved.

There is no single 'correct' volume — the choice is a research decision that trades concentration for accuracy of the draw. Common conventions are 1 mL, 2 mL or 3 mL of bacteriostatic water per vial. Larger volumes give a more dilute solution that is easier to measure on an insulin syringe; smaller volumes give a more concentrated solution that lasts fewer draws. This calculator lets you test any volume instantly.

1 milligram (mg) equals 1000 micrograms (mcg). A U-100 insulin syringe has 100 units per 1 mL, so 1 unit = 0.01 mL. To convert: units to draw = (desired dose in mg ÷ concentration in mg/mL) × 100. The calculator does this automatically as you type.

'U-100' refers to a syringe calibrated for insulin at 100 units per mL. It is the standard laboratory syringe for measuring small volumes of reconstituted peptide because 1 unit represents 0.01 mL — an order of magnitude finer than a 1 mL tuberculin syringe. Sizes commonly used in peptide research are 0.3 mL (30 units), 0.5 mL (50 units) and 1.0 mL (100 units).

Bacteriostatic water contains 0.9% benzyl alcohol, a preservative that inhibits microbial growth in the reconstituted vial. Ordinary sterile water for injection has no preservative, so a multi-dose reconstituted peptide would need to be discarded within 24 hours. Tap or distilled water introduces contamination and pH shifts that can degrade the peptide.

Stability after reconstitution depends on the compound. Typical guidelines: BPC-157 4–6 weeks at 2–8 °C, TB-500 28 days at 2–8 °C, Retatrutide 28 days at 2–8 °C, CJC-1295 + Ipamorelin 28 days at 2–8 °C, GHK-Cu 5–7 days at 2–8 °C or up to 3 months as frozen aliquots at -20 °C. Never refreeze a reconstituted vial.

No. Each draw should use a fresh, sterile syringe and needle. Re-using a syringe introduces bacteria into the vial and damages the rubber stopper, which increases the risk of core-out and contamination on subsequent draws.

Concentration is how much peptide is present per millilitre of solution (mg/mL) — a property of the vial after reconstitution. Dose is the amount of peptide (mcg or mg) drawn for a single research administration. Two vials with the same total mg but different reconstitution volumes have different concentrations, and therefore require different draw volumes to deliver the same dose.

Doses per vial = total peptide in vial (mg) ÷ dose per administration (mg). For example, a 10 mg vial dosed at 500 mcg (0.5 mg) yields 20 doses. The calculator computes this automatically once you enter both the vial size and desired dose.

No. This calculator is provided strictly as a laboratory reference for qualified researchers handling in-vitro peptide solutions. UK Peptides supplies research compounds for laboratory use only. Not for human consumption, cosmetic, veterinary or clinical use.