How the peptide reconstitution calculator works
Reconstitution arithmetic converts a dry, lyophilized amount of research material into a concentration once a known volume of diluent is added. The calculator above uses three record values: the labelled amount of material in the vial (in milligrams), the volume of bacteriostatic water or other diluent added (in millilitres), and a target quantity for the calculation (in micrograms or milligrams). From these it reports the resulting concentration, the volume that contains the target quantity, and the equivalent reading on a U-100 or U-40 syringe scale.
The arithmetic is the same for every compound. A 10 mg vial reconstituted with 2 mL of diluent has a concentration of 5 mg/mL, which is 5,000 mcg/mL. A target quantity of 250 mcg therefore corresponds to 250 ÷ 5,000 = 0.05 mL. On a U-100 scale, where 100 units equal 1 mL, 0.05 mL reads as 5 units. On a U-40 scale it reads as 2 units.
The reconstitution formulas
Concentration (mg/mL) = labelled amount in the vial (mg) ÷ diluent volume (mL). To work in micrograms, multiply milligrams by 1,000: 1 mg = 1,000 mcg.
Volume for a target quantity (mL) = target quantity (mg) ÷ concentration (mg/mL). If the target is in micrograms, convert it to milligrams first or convert the concentration to mcg/mL.
Syringe-scale units = volume (mL) × units per mL. A U-100 scale has 100 units per mL; a U-40 scale has 40 units per mL. Always confirm which scale you are reading, because the same volume gives a different unit number on each scale.
Worked examples for common vial sizes
5 mg vial with 1 mL of diluent: concentration 5 mg/mL (5,000 mcg/mL). A 100 mcg target is 0.02 mL, or 2 units on a U-100 scale.
10 mg vial with 2 mL of diluent: concentration 5 mg/mL. A 250 mcg target is 0.05 mL, or 5 units on a U-100 scale.
10 mg vial with 3 mL of diluent: concentration ≈3.33 mg/mL. A 500 mcg target is 0.15 mL, or 15 units on a U-100 scale.
50 mg vial with 5 mL of diluent: concentration 10 mg/mL. A 1 mg target is 0.1 mL, or 10 units on a U-100 scale. These examples demonstrate arithmetic only; they are not recommended quantities for any purpose.
BAC water and choosing a diluent volume
BAC water is shorthand for bacteriostatic water: sterile water containing 0.9% benzyl alcohol as a preservative. Laboratory protocols often choose a diluent volume that gives a convenient round concentration, such as 1 mg/mL, 2 mg/mL or 5 mg/mL, so that later conversions are easier to check. Adding more diluent lowers the concentration and increases the volume needed for the same target quantity; adding less does the opposite.
Sterile water without a preservative and bacteriostatic water are different presentations. The correct diluent depends on the material, the documented compatibility and the controlling laboratory protocol, not on the calculator.
Blends and total-mass labels
For a blend, enter the amount of the constituent you are calculating, not the total vial mass, unless you specifically want a total-mass concentration. A vial labelled 5 mg CJC-1295 No DAC + 5 mg Ipamorelin contains 10 mg in total. After adding 2 mL of diluent, the total concentration is 5 mg/mL, but each constituent is present at 2.5 mg/mL. Using the 10 mg total for a single constituent would double the calculated concentration of that constituent.
Read the label and batch documentation for the component breakdown. If a blend label states only a total, do not assume an equal split; ask for the component amounts first. Our guide to presentation and blend labels explains the label arithmetic in more detail.
Common calculation mistakes
Mixing units is the most frequent error: entering micrograms where milligrams are expected changes the result by a factor of 1,000. Reading a U-40 scale as if it were U-100 changes the unit reading by a factor of 2.5. Using the total mass of a blend for a single constituent overstates that constituent's concentration. Rounding concentration early, for example 3.33 mg/mL to 3 mg/mL, introduces a 10% error in every later step.
Record the labelled amount, lot number, diluent, volume, preparation time and calculated concentration together, so that another person can check the arithmetic against the batch documentation.
Research use only
This calculator performs laboratory arithmetic for research education. It does not recommend a quantity, frequency, route or use for any material, and it is not medical advice. The Peptide Co. supplies research materials for laboratory use only; they are not for human consumption, diagnosis, prevention or treatment. Confirm every value against the material records and an approved laboratory protocol.