Working with peptides requires navigating a variety of measurement units — milligrams, micrograms, milliliters, IU, and syringe units. Understanding how to convert between these units is essential for accurate dosing and safe peptide administration. This guide provides the formulas and reference tables you need.
Common Peptide Units Explained
| Unit | Abbreviation | What It Measures | Used For |
|---|---|---|---|
| Milligram | mg | Mass (1/1000 of a gram) | Peptide vial sizes, larger doses |
| Microgram | mcg (μg) | Mass (1/1000 of a mg) | Individual peptide doses |
| Milliliter | mL | Volume (1/1000 of a liter) | Liquid volumes, reconstitution |
| International Unit | IU | Biological activity | HGH, HCG, insulin |
| Syringe Unit | units | Volume marking on syringe | Measuring injection volumes |
Key Conversion Formulas
Mass Conversions
| From | To | Formula | Example |
|---|---|---|---|
| mg | mcg | Multiply by 1000 | 5mg = 5,000mcg |
| mcg | mg | Divide by 1000 | 500mcg = 0.5mg |
| g | mg | Multiply by 1000 | 1g = 1,000mg |
Volume Conversions (Insulin Syringes)
| Syringe Size | Total Volume | Total Units | Per Unit |
|---|---|---|---|
| 1mL insulin syringe | 1.0mL | 100 units | 0.01mL per unit |
| 0.5mL insulin syringe | 0.5mL | 50 units | 0.01mL per unit |
| 0.3mL insulin syringe | 0.3mL | 30 units | 0.01mL per unit |
Important: On all standard insulin syringes, 1 unit = 0.01mL. This is universal regardless of syringe size.
Concentration to Dose Calculator
Once you've reconstituted a peptide, use this formula to determine how many syringe units to draw:
Step 1: Calculate concentration = Peptide amount (mcg) ÷ Water added (mL)
Step 2: Calculate volume needed = Desired dose (mcg) ÷ Concentration (mcg/mL)
Step 3: Convert to syringe units = Volume (mL) × 100
Quick Reference: 5mg Vial Reconstituted with 2mL BAC Water
| Desired Dose | Calculation | Volume to Draw | Syringe Units |
|---|---|---|---|
| 100mcg | 100 ÷ 2500 | 0.04mL | 4 units |
| 200mcg | 200 ÷ 2500 | 0.08mL | 8 units |
| 250mcg | 250 ÷ 2500 | 0.10mL | 10 units |
| 500mcg | 500 ÷ 2500 | 0.20mL | 20 units |
| 1000mcg | 1000 ÷ 2500 | 0.40mL | 40 units |
HGH (Human Growth Hormone) IU Conversions
HGH is measured in International Units (IU), which can be confusing. The conversion depends on the manufacturer, but the standard is:
| Measurement | Equivalent | Notes |
|---|---|---|
| 1mg HGH | ~3 IU | Standard pharmaceutical conversion |
| 1 IU HGH | ~0.33mg | Approximately 333mcg |
| 10 IU vial | ~3.33mg | Common vial size |
| 36 IU cartridge | ~12mg | Pen device cartridge |
HGH Dosing Table (10 IU Vial + 1mL BAC Water)
| Desired Dose | Volume to Draw | Syringe Units |
|---|---|---|
| 1 IU | 0.10mL | 10 units |
| 2 IU | 0.20mL | 20 units |
| 3 IU | 0.30mL | 30 units |
| 4 IU | 0.40mL | 40 units |
| 5 IU | 0.50mL | 50 units |
HCG Unit Conversions
HCG (Human Chorionic Gonadotropin) is also measured in IU but at much larger numbers than HGH:
| Vial Size | BAC Water | 250 IU Dose | 500 IU Dose | 1000 IU Dose |
|---|---|---|---|---|
| 5,000 IU | 2mL | 10 units | 20 units | 40 units |
| 5,000 IU | 5mL | 25 units | 50 units | 100 units |
| 10,000 IU | 2mL | 5 units | 10 units | 20 units |
| 10,000 IU | 5mL | 12.5 units | 25 units | 50 units |
Frequently Asked Questions
How many mcg are in 1mg?
There are 1,000 micrograms (mcg) in 1 milligram (mg). So a 5mg peptide vial contains 5,000mcg. To convert mg to mcg, multiply by 1,000. To convert mcg to mg, divide by 1,000. For example, a 250mcg dose equals 0.25mg.
How many units on an insulin syringe equal 1mL?
On a standard insulin syringe, 100 units equals 1mL. Each unit mark represents 0.01mL. This is consistent across all insulin syringe sizes (0.3mL, 0.5mL, and 1.0mL). So if you need to inject 0.20mL, you would draw to the 20-unit mark on the syringe.
How do I convert IU to mg for HGH?
For pharmaceutical-grade HGH, the standard conversion is approximately 1mg = 3 IU (or 1 IU ≈ 0.33mg). So a 2 IU dose equals approximately 0.67mg. Note that this conversion is specific to HGH — IU conversions differ for other substances like HCG and insulin because IU measures biological activity, not mass.
Conclusion
Accurate unit conversion is a foundational skill for peptide dosing. Understanding the relationships between milligrams, micrograms, milliliters, IU, and syringe units ensures you're administering the correct dose every time. When in doubt, always double-check your math before injecting — accuracy matters.