Why Peptide Units Are Confusing
Peptides use various measurement units that can be confusing for beginners. This guide breaks down the different units and how to convert between them.
Common Peptide Measurements
Milligrams (mg)
The standard unit for peptide vial sizes:
- 1mg = 1,000mcg
- Common vial sizes: 2mg, 5mg, 10mg, 15mg
- Used to measure total peptide amount in a vial
Micrograms (mcg or μg)
Used for individual doses:
- 1mcg = 0.001mg (1/1000th of a milligram)
- Common doses: 100mcg, 250mcg, 500mcg
- More precise for smaller doses
International Units (IU)
Used primarily for HGH and some other peptides:
- Based on biological activity, not weight
- 1IU of HGH ≈ 0.33mg (varies by manufacturer)
- Not directly convertible to mg/mcg without knowing the specific peptide
Syringe Units
The markings on insulin syringes:
- 100-unit syringes have marks for 100 units per 1mL
- Each unit = 0.01mL
- 10 units = 0.1mL
Conversion Examples
mg to mcg
| Milligrams | Micrograms |
|---|---|
| 1mg | 1,000mcg |
| 0.5mg | 500mcg |
| 0.25mg | 250mcg |
| 0.1mg | 100mcg |
Calculating Syringe Units
The number of units to draw depends on your reconstitution:
Formula: (Desired dose in mg ÷ Concentration) × 100 = Units to draw
Example 1:
- 5mg vial + 2mL BAC water = 2.5mg/mL concentration
- Want 250mcg (0.25mg) dose
- (0.25 ÷ 2.5) × 100 = 10 units
Example 2:
- 10mg vial + 2mL BAC water = 5mg/mL concentration
- Want 500mcg (0.5mg) dose
- (0.5 ÷ 5) × 100 = 10 units
Understanding Concentration
Concentration (mg/mL) determines how much peptide is in each unit of liquid:
| Concentration | Per 10 units (0.1mL) | Per 20 units (0.2mL) |
|---|---|---|
| 1mg/mL | 100mcg | 200mcg |
| 2.5mg/mL | 250mcg | 500mcg |
| 5mg/mL | 500mcg | 1mg |
Avoid Calculation Errors
Use our Peptide Calculator to automatically calculate:
- How much water to add
- Your resulting concentration
- Exact units to draw for any dose