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HGH Dosage Calculator: How to Calculate Growth Hormone Doses in IU

For educational purposes only. Not medical advice. Full disclaimer
RP
Ryan Peters, PharmD Updated February 2026

Calculating HGH dosage requires understanding International Units (IU), reconstitution volumes, and how to convert between IU and milligrams. This comprehensive guide provides everything you need to accurately dose human growth hormone.

HGH Dosage Calculator: Quick Reference

Use this reference table for common HGH reconstitution scenarios:

HGH VialBAC WaterConcentration2 IU Dose4 IU Dose
10 IU1ml10 IU/ml20 units40 units
10 IU2ml5 IU/ml40 units80 units
12 IU (4mg)1ml12 IU/ml17 units33 units
15 IU (5mg)1.5ml10 IU/ml20 units40 units
18 IU (6mg)1.8ml10 IU/ml20 units40 units
36 IU (12mg)3.6ml10 IU/ml20 units40 units

Understanding HGH Units

IU vs Milligrams

HGH is measured in International Units (IU), but some manufacturers list content in milligrams. The conversion is:

HGH Conversion
  • 1mg HGH = 3 IU (approximate standard)
  • Some brands use 1mg = 2.7 IU
  • Always check your specific product documentation

Common vial sizes:

  • 10 IU = ~3.3mg
  • 12 IU = 4mg
  • 15 IU = 5mg
  • 18 IU = 6mg
  • 36 IU = 12mg

Step-by-Step HGH Dosage Calculation

1 Choose Your Reconstitution Volume

The amount of bacteriostatic water determines your concentration. A common approach is to create a 10 IU/ml concentration for easy math:

Formula: Water volume = Vial IU ÷ Desired concentration

Example: For a 10 IU vial at 10 IU/ml concentration:

  • Water = 10 IU ÷ 10 IU/ml = 1ml

Pro Tip: Creating a 10 IU/ml concentration makes dosing simple: each 10 units on your syringe equals 1 IU of HGH.

2 Calculate Units to Inject

Using a U-100 insulin syringe:

Formula: Syringe units = (Desired IU ÷ Concentration) × 100

Example: You want 4 IU from a 10 IU/ml solution:

  • Units = (4 IU ÷ 10 IU/ml) × 100 = 40 units

3 Simplified Method

With a 10 IU/ml concentration, the math is simple:

  • 1 IU = 10 syringe units
  • 2 IU = 20 syringe units
  • 3 IU = 30 syringe units
  • 4 IU = 40 syringe units
  • 5 IU = 50 syringe units

Standard HGH Dosing Protocols

GoalDaily DoseFrequencyDuration
Anti-aging / General wellness1-2 IUDaily or 5 days on/2 off6-12 months
Fat loss / Body recomposition2-4 IUDaily3-6 months
Muscle building4-6 IUDaily3-6 months
Injury recovery4-8 IUDailyUntil healed

HGH Timing Considerations

When you take HGH affects its interaction with insulin and cortisol:

Best Times to Inject HGH

  • Morning (fasted) - Most common; mimics natural AM cortisol/GH rhythm
  • Pre-workout - May enhance fat burning during exercise
  • Before bed - Amplifies natural nocturnal GH pulse

Split Dosing

For doses above 3-4 IU, splitting into multiple injections may be beneficial:

Example: 6 IU Daily Split
  • Morning (fasted): 3 IU
  • Pre-bed or post-workout: 3 IU

Important: Avoid injecting HGH within 2-3 hours of eating, especially carbohydrates. Elevated insulin blunts GH's fat-burning effects.

HGH Reconstitution Guide

1 Gather Supplies

  • HGH vial (lyophilized powder)
  • Bacteriostatic water
  • Alcohol swabs
  • Insulin syringe (for mixing and injecting)

2 Add Water Carefully

  • Clean both vial stoppers with alcohol
  • Draw desired amount of BAC water into syringe
  • Inject slowly along vial wall (not directly on powder)
  • Let it dissolve naturally - do NOT shake

3 Storage After Reconstitution

  • Refrigerate immediately (2-8°C / 36-46°F)
  • Use within 3-4 weeks
  • Never freeze reconstituted HGH
  • Protect from light

HGH Dosage by Vial Size

10 IU Vial Examples

Daily DoseIf Using 1ml BAC WaterDays Per Vial
2 IU20 units5 days
3 IU30 units3.3 days
4 IU40 units2.5 days

36 IU Vial Examples

Daily DoseIf Using 3.6ml BAC WaterDays Per Vial
2 IU20 units18 days
4 IU40 units9 days
6 IU60 units6 days

Frequently Asked Questions

How do I calculate HGH dosage in IU?

To calculate HGH dosage: First determine your concentration (vial IU ÷ ml of water added). Then calculate syringe units: (desired IU ÷ concentration) × 100. For example, with a 10 IU vial reconstituted in 1ml (10 IU/ml), getting 2 IU requires: (2 ÷ 10) × 100 = 20 syringe units.

How many IU is 1mg of HGH?

The standard conversion is 1mg of HGH equals approximately 3 IU. However, some manufacturers use slightly different conversions (2.7-3.0 IU per mg). Always check your specific product's labeling for the exact conversion used by that manufacturer.

What is a good starting dose for HGH?

Most protocols recommend starting with 1-2 IU daily for anti-aging and general wellness purposes. For fat loss and body recomposition, 2-4 IU daily is common. Starting low allows you to assess tolerance and minimize side effects like water retention and joint pain before increasing if needed.

How much bacteriostatic water do I add to HGH?

The amount of bacteriostatic water is flexible and determines your concentration. A simple approach is to create a 10 IU/ml concentration: add 1ml to a 10 IU vial, 1.5ml to a 15 IU vial, or 3.6ml to a 36 IU vial. This makes dose calculation easy since every 10 syringe units equals 1 IU of HGH.

Summary

Accurate HGH dosage calculation starts with understanding the relationship between IU, milligrams, and reconstitution volumes. Create a convenient concentration like 10 IU/ml for easy math, always use bacteriostatic water, and maintain proper storage to preserve potency.

Start with lower doses to assess tolerance, time your injections away from meals, and consider splitting larger daily doses for optimal results.