Peptide Reconstitution Volume Calculator — How to Get from mg/Vial to mcg/Unit
The math is short. One U-100 insulin syringe unit holds 0.01 mL — that single conversion does most of the work. Once you know how many micrograms of peptide sit in 1 mL of reconstituted solution, the per-unit figure is just that number divided by 100.
The formula:
(mg peptide in vial × 1000) ÷ (mL of bacteriostatic water added) = mcg per mL
(mcg per mL) ÷ 100 = mcg per insulin syringe unit
Worked examples
5 mg peptide vial + 2 mL bacteriostatic water:
- 5 × 1000 = 5,000 mcg total
- 5,000 ÷ 2 = 2,500 mcg/mL
- 2,500 ÷ 100 = 25 mcg per syringe unit
A 250 mcg dose lands at 10 units. Double it for 500 mcg: 20 units.
5 mg peptide vial + 1 mL bacteriostatic water:
- 5,000 ÷ 1 = 5,000 mcg/mL
- 50 mcg per syringe unit
Now 250 mcg is only 5 units, and 1 mg reads as 20 units. Halving the water doubles the concentration — same vial, different syringe math. Worth keeping in mind before you draw.
10 mg peptide vial + 2 mL bacteriostatic water:
- 10,000 ÷ 2 = 5,000 mcg/mL
- 50 mcg per syringe unit
Common reconstitution volumes for research peptides
A starting point, not a recommendation. Research protocols set their own volumes around study design and stability requirements.
| Vial | Common reconstitution | Final concentration | Per syringe unit | |---|---|---|---| | 5 mg | 2 mL | 2,500 mcg/mL | 25 mcg | | 5 mg | 1 mL | 5,000 mcg/mL | 50 mcg | | 10 mg | 2 mL | 5,000 mcg/mL | 50 mcg | | 10 mg | 1 mL | 10,000 mcg/mL | 100 mcg | | 15 mg | 3 mL | 5,000 mcg/mL | 50 mcg | | 2 mg (CJC-1295 typical) | 1 mL | 2,000 mcg/mL | 20 mcg | | 2 mg (Ipamorelin typical) | 1 mL | 2,000 mcg/mL | 20 mcg |
Why diluent quality matters for the math
Every number above assumes one thing: the diluent was sterile and inert at the moment of mixing. Break that assumption and the whole calculation is moot. A non-sterile diluent compromises the reconstituted vial across the entire 28-day cold-storage window after the first puncture, not just on day one. The bacteriostatic-water spec common in research protocols is USP <71>-tested, 0.9% benzyl alcohol, refrigerated after first puncture, and discarded at 28 days.
Where to source bacteriostatic water that documents this:
- BAC Water Depot — per-lot CoA, USP <71>, US-shipped 10 mL vials
- Hospira / Pfizer (via institutional distributor) — incumbent pharma-grade product, lead time 3–5 days
- A licensed compounding pharmacy — clinical-grade, usually requires a prescription for clinical use
A note on what this calculator does not do
It does the arithmetic. That's all. It will not recommend a dose, validate a protocol, or stand in for the design judgment of a researcher reading current literature. For research and laboratory use only — not medical or clinical guidance.