Peptide Calculator: How to Calculate Accurate Peptide Doses

A peptide calculator is a simple tool used to determine the correct dosage after reconstituting (mixing) a lyophilized peptide with bacteriostatic water. Because most peptides come in powder form and must be mixed before use, accurate math is essential to ensure proper dosing.

This guide explains how peptide calculations work so you can confidently determine the correct amount per injection.

Step 1: Understand the Basic Components

When using a peptide calculator, you need three pieces of information:

1. Total peptide amount in the vial (e.g., 5 mg)

2. Amount of bacteriostatic water added (e.g., 2 mL)

3. Desired dose per injection (e.g., 250 mcg)

Step 2: Convert mg to mcg

Most peptide dosages are measured in micrograms (mcg).

• 1 mg = 1,000 mcg

• 5 mg = 5,000 mcg

Always convert everything into the same unit before calculating.

Step 3: Calculate Concentration

Use this formula:

Total mcg in vial ÷ Total mL added = mcg per mL

Example:

If you have:

• 5 mg vial (5,000 mcg)

• Add 2 mL bacteriostatic water

Calculation:

5,000 mcg ÷ 2 mL = 2,500 mcg per mL

So now:
1 mL = 2,500 mcg

Step 4: Calculate Your Injection Volume

Now determine how much liquid you need for your desired dose.

Example: You want 250 mcg.

Formula:

Desired dose ÷ mcg per mL = mL per injection

250 mcg ÷ 2,500 mcg = 0.1 mL

So you would inject:

0.1 mL

Using an Insulin Syringe (Units)

Most peptides are measured with insulin syringes (U-100), where:

• 1 mL = 100 units

• 0.1 mL = 10 units

In our example:

0.1 mL = 10 units on an insulin syringe

Quick Reference Example Table

Universal Peptide Calculation Formula

You can always use this simplified formula:

(Desired dose ÷ Total peptide amount) × Total water added = Injection volume

Example:

• 250 mcg desired

• 5,000 mcg total

• 2 mL water

(250 ÷ 5,000) × 2 = 0.1 mL

Tips for Accurate Peptide Dosing

• Always double-check unit conversions

• Use a sterile insulin syringe (U-100 standard)

• Store reconstituted peptides in the refrigerator

• Avoid shaking the vial (gently swirl instead)

• Label your vial with the concentration

Common Mistakes to Avoid

1. Forgetting to convert mg to mcg

2. Confusing insulin units with milliliters

3. Adding the wrong amount of bacteriostatic water

4. Misreading syringe markings

Even small math errors can significantly change your dose.

Safety Note

Peptides are often sold as research compounds and are not approved for general medical use in many countries. Always consult a qualified healthcare professional before using any injectable compound. Hormonal and biologically active peptides can have systemic effects and potential side effects.