Peptide Reconstitution Calculator

Calculate the concentration when mixing lyophilized peptides with bacteriostatic water.

Amount in the vial (milligrams)

Bacteriostatic water to add

Concentration

mcg per ml

Per Insulin Unit

mcg per unit (100u syringe)

How to Use This Calculator

  1. Enter the peptide amount – This is the total milligrams (mg) in your peptide vial. Common sizes include 5mg, 10mg, and 15mg.
  2. Enter the BAC water amount – This is how much bacteriostatic water you'll add. More water = lower concentration (easier to measure small doses). Less water = higher concentration.
  3. Read your results – The calculator shows your concentration in mcg/ml and how many micrograms are in each unit on a 100-unit insulin syringe.

Understanding the Math

The reconstitution formula is straightforward:

Concentration (mcg/ml) = (Peptide mg × 1000) ÷ Water ml

For insulin syringe units (100 units = 1 ml):

mcg per unit = Concentration ÷ 100

Common Reconstitution Examples

Peptide Water Concentration mcg/unit
5mg2ml2,500 mcg/ml25 mcg
5mg2.5ml2,000 mcg/ml20 mcg
10mg2ml5,000 mcg/ml50 mcg
10mg5ml2,000 mcg/ml20 mcg

Frequently Asked Questions

There's no single "correct" amount. Using more water creates a lower concentration, making it easier to measure smaller doses accurately. A common approach is 1-2ml per 5mg of peptide. For very small doses, consider using more water.
1 milligram (mg) = 1,000 micrograms (mcg). Peptide vials are typically measured in mg, while doses are often measured in mcg. This calculator converts between the two automatically.
Most people use U-100 insulin syringes, which have 100 units per 1ml. This calculator assumes you're using a 100-unit syringe. The "mcg per unit" result tells you how much peptide is in each unit marking on your syringe.
When stored properly in a refrigerator (2-8°C), most reconstituted peptides remain stable for 4-6 weeks. The bacteriostatic water contains benzyl alcohol which helps prevent bacterial growth. Never freeze reconstituted peptides.