Peptide dosing can seem complex at first — micrograms vs milligrams, vial sizes, concentrations, syringe units. This guide demystifies the entire process with a simple framework applicable to every peptide.
The Core Math: Units to Volume
All peptide dosing comes down to one calculation:
Draw volume (mL) = Desired dose (mg) ÷ Concentration (mg/mL)
Where concentration = Vial size (mg) ÷ BAC water added (mL)
Example: 5mg BPC-157 vial + 1mL BAC water = 5mg/mL concentration
For 500mcg dose: 0.5mg ÷ 5mg/mL = 0.1mL = 10 units on a U-100 syringe
Microgram vs Milligram Conversion
1mg = 1000mcg. Most healing/nootropic peptides are dosed in mcg. Most GLP-1 peptides are dosed in mg.
mcg examples: BPC-157 (250-500mcg), Ipamorelin (100-200mcg), PT-141 (1000-2000mcg)
mg examples: TB-500 (2.5-5mg), Semaglutide (0.25-2.4mg), Epithalon (5-10mg)
Syringe Reference: Units to mL
U-100 insulin syringes (standard): 100 units = 1mL
- 10 units = 0.1mL
- 5 units = 0.05mL
- 1 unit = 0.01mL
For mcg dosing with 1mL BAC water in a 5mg vial (5000mcg/mL):
- 250mcg dose = 5 units
- 500mcg dose = 10 units
- 1000mcg dose = 20 units
Use the PeptideWiki calculator to automate this for any combination.
Weight-Based vs Fixed Dosing
Some peptides use weight-based dosing (primarily in clinical research): dosage in mcg/kg or mg/kg.
BPC-157: Often studied at 10mcg/kg in animals; most human researchers use fixed 250-500mcg
Semaglutide: Fixed dose escalation (not weight-based)
Ipamorelin/CJC: Fixed 100-200mcg per injection regardless of weight
For most peptides in the research community, fixed dosing based on published protocols is more practical than weight-based calculation.
Key Takeaways
Master the core formula (volume = dose ÷ concentration) and the unit-to-mL conversion (100 units = 1mL on U-100 syringe) and you can calculate any peptide dose. The PeptideWiki calculator handles all of this automatically.