How to Calculate Peptide Dosage: The Complete Guide
Complete guide to peptide dosage calculation. Concentration, units, mcg to ml conversion, and worked examples for BPC-157, ipamorelin, and more. Beginner-friendly.
Overview
Peptide dosing requires understanding concentration (how much peptide per ml of solution) and converting your desired dose (in mcg) to an injection volume (in ml or insulin syringe units). This guide makes the math simple.
What You Need
- Peptide vial (note the mg amount on the label)
- Bacteriostatic water
- Calculator
- Insulin syringe (100-unit markings)
Step-by-Step Instructions
Identify your peptide vial amount
Check the label. Common sizes: 2mg, 5mg, 10mg. This is the total amount of peptide in the vial. Convert to mcg: 1mg = 1,000mcg. So a 5mg vial = 5,000mcg total.
Decide how much bacteriostatic water to add
The amount of BW you add determines your concentration. Common choice: add 1ml (100 units) of BW to a 5mg vial. This gives you 5mg/ml = 5,000mcg/ml.
Calculate your concentration
Concentration (mcg/ml) = Total mcg ÷ ml of BW added. Example: 5,000mcg ÷ 1ml = 5,000mcg/ml. Or: 5,000mcg ÷ 2ml = 2,500mcg/ml.
Calculate your injection volume
Volume (ml) = Desired dose (mcg) ÷ Concentration (mcg/ml). Example: You want 250mcg from a 5,000mcg/ml solution. 250 ÷ 5,000 = 0.05ml.
Convert ml to insulin syringe units
Insulin syringes have 100 units = 1ml. So: Units = Volume (ml) × 100. Example: 0.05ml × 100 = 5 units on the syringe. Draw to the '5' mark.
Verify with a worked example
BPC-157 example: 5mg vial + 1ml BW = 5,000mcg/ml. Desired dose: 500mcg. Volume = 500 ÷ 5,000 = 0.1ml = 10 units. Draw to the '10' mark on a 100-unit insulin syringe.
Common Mistakes to Avoid
Confusing mg and mcg
Fix: 1mg = 1,000mcg. Always convert your vial amount to mcg first before calculating.
Forgetting to account for how much BW was added
Fix: Your concentration depends entirely on how much BW you added. Always calculate concentration fresh if you are unsure.
Using a 50-unit syringe and applying 100-unit math
Fix: Check your syringe. A 50-unit syringe has 50 units = 0.5ml. A 100-unit syringe has 100 units = 1ml. The math changes accordingly.
Not writing down the concentration
Fix: Write the concentration on a piece of tape on the vial. You will need it every time you dose.
Frequently Asked Questions
What is the difference between mg and mcg?
1mg = 1,000mcg (micrograms). Peptide vials are labeled in mg; doses are usually expressed in mcg. Always convert before calculating.
What if I add 2ml of BW instead of 1ml?
Your concentration halves. A 5mg vial + 2ml BW = 2,500mcg/ml instead of 5,000mcg/ml. You would need to draw twice as much volume for the same dose.
How do I know how many units to draw on my syringe?
Units = (Desired dose in mcg ÷ Concentration in mcg/ml) × 100. Example: 500mcg ÷ 5,000mcg/ml × 100 = 10 units.
Can I use a 0.5ml syringe?
Yes. A 0.5ml (50-unit) syringe works the same way: 50 units = 0.5ml. Use the same formula but note that the maximum dose you can draw is 0.5ml.
Peptides Covered in This Guide
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