How to Calculate Peptide Dosages: Complete Dosing Math Guide (2026)
Master peptide dosage calculations with our step-by-step guide. Learn reconstitution math, syringe measurements, and create accurate dosing protocols for any peptide.
One of the most confusing aspects of peptide research is calculating accurate dosages. With vials containing milligrams of powder, syringes measured in units, and protocols calling for micrograms, the math can seem overwhelming. This comprehensive guide breaks down peptide dosage calculations into simple, repeatable steps.
🔑 Key Takeaways
- Peptide concentration = mg of peptide ÷ mL of bacteriostatic water
- Standard insulin syringes (100 units) equal 1 mL total volume
- The golden formula: Desired dose ÷ Concentration = Volume to draw
- Always double-check calculations before proceeding
Understanding the Basics: Units of Measurement
Before diving into calculations, you need to understand the units involved in peptide dosing:
Weight Measurements
- Milligrams (mg): How peptide vials are typically sold (5mg, 10mg, etc.)
- Micrograms (mcg or μg): How doses are typically measured (100mcg, 250mcg, etc.)
- Conversion: 1 mg = 1,000 mcg
Volume Measurements
- Milliliters (mL): Volume of bacteriostatic water added
- Units (IU on syringe): Markings on insulin syringes
- Conversion: 100 units = 1 mL on a standard U-100 insulin syringe
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Apollo PeptidesStep 1: Calculate Your Peptide Concentration
The first step is determining how concentrated your reconstituted peptide solution will be. This depends on two factors:
- How much peptide is in your vial (in mg)
- How much bacteriostatic water you add (in mL)
The Concentration Formula
Concentration Formula
Concentration (mcg/unit) = (Peptide mg × 1000) ÷ (Water mL × 100)
Or simplified: Concentration = (Peptide mg × 10) ÷ Water mL mcg per unit
Example Calculation
You have a 5mg vial of BPC-157 and add 2mL of bacteriostatic water:
| Given | Value |
|---|---|
| Peptide amount | 5 mg (= 5,000 mcg) |
| Water added | 2 mL (= 200 units) |
| Concentration | 5,000 ÷ 200 = 25 mcg per unit |
Now every 1 unit on your syringe contains 25 mcg of BPC-157.
Step 2: Calculate How Much to Draw
Once you know your concentration, calculating the volume to draw for any dose is straightforward:
Dosing Formula
Units to draw = Desired dose (mcg) ÷ Concentration (mcg/unit)
Example: Drawing a 250mcg Dose
Using our 5mg/2mL BPC-157 solution (25 mcg/unit):
250 mcg ÷ 25 mcg/unit = 10 units
Draw to the 10-unit mark on your insulin syringe for a 250mcg dose.
Quick Reference: Common Reconstitution Scenarios
Here are pre-calculated concentrations for the most common scenarios:
| Vial Size | Water Added | Concentration | 100mcg Dose | 250mcg Dose | 500mcg Dose |
|---|---|---|---|---|---|
| 5 mg | 1 mL | 50 mcg/unit | 2 units | 5 units | 10 units |
| 5 mg | 2 mL | 25 mcg/unit | 4 units | 10 units | 20 units |
| 5 mg | 2.5 mL | 20 mcg/unit | 5 units | 12.5 units | 25 units |
| 10 mg | 2 mL | 50 mcg/unit | 2 units | 5 units | 10 units |
| 10 mg | 3 mL | 33.3 mcg/unit | 3 units | 7.5 units | 15 units |
| 2 mg | 1 mL | 20 mcg/unit | 5 units | 12.5 units | 25 units |
Complete Reconstitution to Dosing Workflow
Gather Your Information
Note the amount of peptide in your vial (check the label - usually 5mg or 10mg). Decide how much bacteriostatic water you'll use.
Calculate Your Concentration
Use the formula: (mg × 10) ÷ mL = mcg per unit. Write this number down and keep it with your vial.
Reconstitute the Peptide
Follow proper reconstitution procedures: add water slowly along the vial wall, swirl gently (never shake), and wait for complete dissolution.
Calculate Your Dose
Divide your desired dose (in mcg) by your concentration (mcg/unit) to find how many units to draw.
Draw and Administer
Use a clean insulin syringe, draw the calculated volume, and follow proper injection technique.
Working with Different Peptide Types
Growth Hormone Secretagogues
Peptides like Ipamorelin, CJC-1295, and GHRP-6 typically come in larger vials (2-5mg) with higher dose requirements (100-300mcg). A common approach:
- 5mg vial + 2.5mL water = 20 mcg/unit
- For 200mcg dose: 200 ÷ 20 = 10 units
Healing Peptides
Peptides like BPC-157 and TB-500 are often dosed at 250-500mcg:
- 5mg vial + 2mL water = 25 mcg/unit
- For 250mcg: 250 ÷ 25 = 10 units
- For 500mcg: 500 ÷ 25 = 20 units
Learn more about healing peptide protocols in our Best Peptides for Healing Injuries guide.
Cognitive/Nootropic Peptides
Peptides like Semax and Selank may have different delivery methods (nasal sprays) with their own concentration calculations. For injectable forms:
- Doses typically range 200-600mcg
- Same math applies for reconstitution
Explore cognitive peptides in our Best Peptides for Cognitive Function guide.
Weight-Based Dosing Calculations
Some research protocols specify doses based on body weight (e.g., mcg per kg). Here's how to calculate:
Weight-Based Formula
Total dose (mcg) = Body weight (kg) × Dose per kg (mcg/kg)
Example: Weight-Based BPC-157 Dosing
A protocol calls for 10 mcg/kg of BPC-157. For a 75kg individual:
75 kg × 10 mcg/kg = 750 mcg total dose
Using our 25 mcg/unit solution: 750 ÷ 25 = 30 units
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Apollo PeptidesAccounting for Dead Space
Syringes have a small amount of "dead space" - volume that remains in the syringe hub after injection. For standard insulin syringes, this is typically 0.5-1 unit. For most purposes, this is negligible, but for precise research:
- Use low dead-space syringes if available
- Draw slightly more and inject to the stop
- Account for ~1% loss in calculations for critical research
Calculating Vial Duration
Knowing how long a vial will last helps with planning and budgeting:
Vial Duration Formula
Number of doses = Total peptide (mcg) ÷ Dose size (mcg)
Days supply = Number of doses ÷ Doses per day
Example Calculation
A 5mg (5,000mcg) vial with 250mcg twice daily dosing:
| Calculation | Result |
|---|---|
| Total doses | 5,000 ÷ 250 = 20 doses |
| Days supply | 20 ÷ 2 = 10 days |
Common Mistakes to Avoid
- Confusing mg and mcg: Always double-check your unit conversions. 1mg = 1,000mcg!
- Using wrong syringe markings: Ensure you're using U-100 insulin syringes where 100 units = 1mL
- Not recording concentration: Always write down your concentration and keep it with the vial
- Inconsistent water volumes: Use the same amount of water each time for consistent dosing
- Mental math errors: Use a calculator - even simple math mistakes can cause significant dosing errors
Quick Calculation Cheat Sheet
Save this reference for quick calculations:
Related Guides
Master your peptide research with these complementary resources:
- How to Reconstitute Peptides - Proper reconstitution technique
- How to Inject Peptides - Subcutaneous injection guide
- How to Store Peptides - Maximize peptide stability
- Peptide Stacking Guide - Combining peptides effectively
- Best Peptides for Beginners - Starting your research
Frequently Asked Questions
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