For research and educational purposes only. Peptides are not approved for human use unless specifically indicated. Read full disclaimer.
PeptideHub

Peptide reconstitution & dosage calculator

Free, accurate, mobile-friendly. Compute exact insulin-syringe units to draw, doses per vial, and vials needed per cycle for the most commonly studied research peptides.

Common research range for BPC-157: 250–500 mcg, 2× daily, subcutaneous. Cycle: 4 weeks on / 2 off.

Educational use only. This calculator performs unit math on the values you provide and is not a substitute for medical advice. Verify every calculation independently.

Result

Concentration
2500 mcg / mL
Per syringe unit
25.00 mcg / unit
Draw to this mark
15.0 units (0.15 mL)
Dose, all units
375 mcg · 0.375 mg
Doses per vial
13.3 doses
Days per vial
6.7 days
Vials needed for 4-week cycle
5 vials

Numbers are computed from your inputs. Verify all calculations independently. Educational use only.

How the calculator works

Lyophilized peptides arrive in milligram quantities (typically 2, 5, or 10 mg). To inject them you reconstitute with bacteriostatic water — a sterile saline with 0.9% benzyl alcohol that preserves the solution. The amount of water you add determines the concentration (mcg/mL), which determines how many syringe units correspond to your target dose.

The math, in one line

units to draw = (target mcg × syringe units per mL) ÷ (vial mcg ÷ diluent mL)

Worked example

  • 5 mg BPC-157 vial reconstituted with 2 mL bac water = 2,500 mcg/mL.
  • U-100 syringe means 1 mL = 100 units, so 1 unit = 25 mcg.
  • To dose 250 mcg, draw 10 units (0.10 mL).
  • A 5 mg vial yields 20 doses at 250 mcg.

Common mistakes the calculator prevents

  • Overflowing the syringe. If a dose requires more units than your syringe holds, the calculator warns you and recommends reducing diluent.
  • Forgetting unit conversions. Many users confuse mg, mcg, mL, and "units." The calculator displays all four side by side.
  • Cycle planning. Buying one 5 mg vial when your 4-week protocol needs three is a common error — the calculator computes vials per cycle.

Frequently asked questions

How do I use the peptide reconstitution calculator?+

Pick a peptide, enter the vial size in mg and how much bacteriostatic water you'll add in mL, then enter your target dose in mcg. The calculator returns the concentration, exactly how many insulin-syringe units to draw, and how many doses (and days) your vial will last.

What insulin syringe should I use for peptide injections?+

Most peptide protocols use U-100 insulin syringes (either 1 mL or 0.5 mL). U-100 means 100 units per mL. A 30G or 31G needle is common for subcutaneous use because of low injection-site irritation.

How do I convert mcg to insulin syringe units?+

After reconstitution, your vial has a known concentration in mcg/mL. Divide that by the syringe's units-per-mL (100 for U-100). The result is mcg per unit; divide your dose by that to get the units to draw. The calculator does this automatically.

How much bacteriostatic water should I add?+

There's no single answer — more water makes the math easier (typically 2 mL for a 5 mg vial gives clean numbers), while less water lets you fit smaller doses into smaller syringes. Use the calculator to find what makes your target dose draw to a clean unit mark.

How long does a reconstituted peptide last?+

Most reconstituted peptides remain stable for around 30 days when refrigerated (2–8°C) and protected from light. Some (e.g., GHK-Cu) are light-sensitive and should be wrapped or stored in dark vials.