Reconstitution Math Fundamentals
The two divisions behind every draw volume: concentration and dose conversion, plus the unit errors that cause real harm.
The only two formulas that matter
Every legitimate reconstitution calculation is two divisions. First: concentration = total peptide in the vial ÷ diluent volume added. A 5 mg vial reconstituted with 2 mL of bacteriostatic water contains 2.5 mg/mL. Second: draw volume = prescribed dose ÷ concentration. A clinician-prescribed 250 mcg dose at 2.5 mg/mL (2,500 mcg/mL) is 0.1 mL.
Units: where the danger lives
- 1 mg = 1,000 mcg. Confusing them produces a 1,000× dosing error — the single most dangerous mistake in this space.
- On a U-100 insulin syringe, 1 unit = 0.01 mL, so 0.1 mL reads as 10 units.
- Diluent volume changes concentration, never the total peptide in the vial. More diluent = larger, easier-to-read draws of the same dose.
What math cannot do
Arithmetic converts a prescribed dose into a syringe reading. It cannot generate the dose itself — for most research peptides no established human dose exists, which is why honest calculators require the dose as an input from a prescription rather than suggesting one.
Knowledge check
Answer 5 questions — 4 correct passes and earns 50 points.
1. A 5 mg vial is reconstituted with 2.5 mL of bacteriostatic water. What is the concentration?
2. A clinician prescribes 200 mcg. The vial is at 2 mg/mL. What draw volume is needed?
3. How does 0.1 mL read on a U-100 insulin syringe?
4. Adding MORE bacteriostatic water to a vial does what?
5. Why do honest peptide calculators refuse to suggest a dose?
Points are credited once per module, up to 5 point-earning completions per calendar month. Back to all modules