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How to Convert 100mcg to ML for Peptide Dosing

Last updated: February 6, 2026

Converting 100mcg to ml for peptide dosing isn't a direct conversion - it depends entirely on your reconstitution concentration. This guide explains how mcg to ml conversion works and provides reference tables for common peptide concentrations.

Why 100mcg Doesn't Equal a Fixed ML Amount

Unlike simple unit conversions (like inches to centimeters), converting micrograms (mcg) to milliliters (ml) requires knowing one additional piece of information: your concentration.

The same 100mcg dose could be:

  • 0.1ml from a 1mg/ml solution
  • 0.05ml from a 2mg/ml solution
  • 0.02ml from a 5mg/ml solution

Key Point: mcg is a measure of mass (how much peptide). ml is a measure of volume (how much liquid). The concentration (mg/ml or mcg/ml) bridges these two measurements.

The Conversion Formula

To convert any mcg dose to ml:

Master Formula

ml to inject = Dose (mcg) ÷ Concentration (mcg/ml)

Example: You want 100mcg from a peptide reconstituted at 1000mcg/ml (1mg/ml):

  • ml = 100mcg ÷ 1000mcg/ml = 0.1ml (or 10 units on a U-100 syringe)

100mcg to ML Conversion Table

Reference table for converting 100mcg to ml at common peptide concentrations:

Concentration100mcg EqualsSyringe Units (U-100)
200mcg/ml (0.2mg/ml)0.5ml50 units
250mcg/ml (0.25mg/ml)0.4ml40 units
500mcg/ml (0.5mg/ml)0.2ml20 units
1000mcg/ml (1mg/ml)0.1ml10 units
2000mcg/ml (2mg/ml)0.05ml5 units
2500mcg/ml (2.5mg/ml)0.04ml4 units
5000mcg/ml (5mg/ml)0.02ml2 units

How to Determine Your Concentration

1 Know Your Peptide Amount

Check the vial label for total peptide content (usually in mg).

2 Know How Much Water You Added

Record the exact amount of bacteriostatic water used for reconstitution.

3 Calculate Concentration

Concentration = Peptide amount ÷ Water volume

Example: 5mg peptide + 2ml BAC water:

  • Concentration = 5mg ÷ 2ml = 2.5mg/ml
  • In mcg: 2.5mg/ml = 2500mcg/ml

Common Peptide Scenarios

BPC-157 (typically 5mg vials)

BAC Water AddedConcentration100mcg = 250mcg =
1ml5mg/ml (5000mcg/ml)2 units5 units
2ml2.5mg/ml (2500mcg/ml)4 units10 units
2.5ml2mg/ml (2000mcg/ml)5 units12.5 units

Ipamorelin/CJC-1295 (typically 2mg or 5mg vials)

Vial SizeBAC WaterConcentration100mcg =
2mg2ml1mg/ml (1000mcg/ml)10 units
2mg1ml2mg/ml (2000mcg/ml)5 units
5mg2.5ml2mg/ml (2000mcg/ml)5 units
5mg2ml2.5mg/ml (2500mcg/ml)4 units

Semaglutide (typically 3mg or 5mg vials)

Vial SizeBAC WaterConcentration250mcg =500mcg =
3mg3ml1mg/ml25 units50 units
5mg2.5ml2mg/ml12.5 units25 units
5mg2ml2.5mg/ml10 units20 units

Using Insulin Syringes

Most peptide users use U-100 insulin syringes, where:

Syringe Conversion
  • 100 units = 1ml
  • 50 units = 0.5ml
  • 10 units = 0.1ml
  • 1 unit = 0.01ml

To convert ml to syringe units:

Syringe units = ml × 100

Quick Mental Math Trick

For peptides reconstituted at exactly 1mg/ml (1000mcg/ml):

  • 100mcg = 10 units
  • 200mcg = 20 units
  • 250mcg = 25 units
  • 500mcg = 50 units

The dose in mcg divided by 10 equals syringe units. This is why 1mg/ml is a popular concentration choice.

Pro Tip: When reconstituting peptides, choose water volumes that create easy-to-calculate concentrations like 1mg/ml, 2mg/ml, or 2.5mg/ml.

Avoiding Common Mistakes

  • Don't assume universal conversion - 100mcg to ml changes based on YOUR concentration
  • Write down your reconstitution - Record how much water you added to each vial
  • Double-check the math - Verify calculations before injecting
  • Label your vials - Write the concentration on the vial after reconstitution
  • Remember mcg vs mg - 1000mcg = 1mg. Don't confuse these!

Frequently Asked Questions

How many ml is 100mcg of peptide?

The ml equivalent of 100mcg depends on your reconstitution concentration. At 1mg/ml (1000mcg/ml), 100mcg equals 0.1ml or 10 units on an insulin syringe. At 2mg/ml, it's 0.05ml (5 units). At 5mg/ml, it's just 0.02ml (2 units). You must know your specific concentration to calculate accurately.

How do I convert mcg to ml for peptides?

Use the formula: ml = dose (mcg) ÷ concentration (mcg/ml). First determine your concentration by dividing the peptide amount by the water volume you added. Then divide your desired mcg dose by that concentration. To get syringe units, multiply the ml result by 100.

What is 100mcg in mg?

100mcg (micrograms) equals 0.1mg (milligrams). There are 1000 micrograms in 1 milligram. So to convert mcg to mg, divide by 1000. For example: 250mcg = 0.25mg, 500mcg = 0.5mg, 1000mcg = 1mg.

How many units is 100mcg on an insulin syringe?

The number of units depends on your peptide concentration. At 1mg/ml, 100mcg is 10 units. At 2mg/ml, it's 5 units. At 2.5mg/ml, it's 4 units. Calculate using: units = (mcg ÷ concentration in mcg/ml) × 100. Or simply: units = (mcg ÷ mg/ml concentration) ÷ 10.

Summary

Converting 100mcg to ml for peptides requires knowing your reconstitution concentration. There's no universal answer because the same mcg dose requires different volumes depending on how concentrated your solution is.

The key formula is: ml = mcg ÷ concentration (mcg/ml)

For easiest calculations, reconstitute peptides to create simple concentrations like 1mg/ml or 2mg/ml, and always label your vials with the concentration after mixing.