PepCalc: peptide reconstitution calculator
Free, private and offline. Work out how much water to add to a peptide vial, the concentration in mg per mL, and how far to draw on your syringe. Everything stays on your device.
What it does
- Reconstitution: the concentration from the amount in the vial and the water added (mg, mcg or IU per mL)
- Draws: the volume in mL and the units on U-100 and U-40 insulin syringes, drawn on a picture of the syringe
- Blends: vials holding more than one peptide
- A shelf of vials, with each draw logged and the amount left
- Estimated levels in the body over time, only for peptides with published human data, each with its source
- A journal of weight and BMI, blood sugar, side effects and progress photos, with trends to share
- A PDF report of draws, levels and journal entries
Peptides in the catalog
Semaglutide, Tirzepatide, Retatrutide, Cagrilintide, Tesamorelin, BPC-157, TB-500, GHK-Cu, KPV, GLOW, KLOW, or any peptide you add yourself.
The arithmetic
Concentration = amount in the vial ÷ water added. Volume to draw (mL) = amount ÷ concentration. On a U-100 syringe, units = mL × 100.
Questions
- How much bacteriostatic water should I add to a peptide vial?
- PepCalc shows what each amount of water does: the concentration it makes and how many units each draw takes on your syringe, so you can pick a volume that is easy to measure. It does not tell you what to use.
- How do I convert mg to units on an insulin syringe?
- Divide the amount by the concentration to get millilitres, then multiply by 100 for a U-100 syringe (or by 40 for U-40). A 10 mg vial with 2 mL of water is 5 mg per mL, and 0.1 mL of it is 10 units on a U-100 syringe.
- Does PepCalc recommend doses?
- No. It does arithmetic and shows sourced references; the amount is yours to enter.
- Where is my data stored?
- Only on your device. There is no account, no server and no analytics, and PepCalc works offline once it has loaded.
- Is PepCalc free?
- Yes, with no ads or paywall. It is open source under the GNU AGPL-3.0.
PepCalc is not medical advice and never recommends a dose. Source code