Reconstitution concentration formula: C = P / V, where C = concentration (mg/mL), P = peptide mass (mg), V = volume of BAC water (mL). Standard insulin syringes are 1mL = 100 units (U-100). Therefore: dose in units = (desired dose in mcg × 100) / (concentration in mcg/mL). Common reconstitution reference table: 5mg vial + 1mL BAC = 5mg/mL (50mcg/unit); 5mg + 2mL = 2.5mg/mL (25mcg/unit); 10mg + 2mL = 5mg/mL (50mcg/unit); 10mg + 3mL = 3.33mg/mL (33.3mcg/unit). Using more BAC water gives a lower concentration — easier to measure small doses accurately but requires larger injection volumes and vial depletes faster. Using less BAC water gives higher concentration — smaller injection volumes, more doses per vial, but harder to measure very small doses. IMPORTANT: Adding more or less BAC water does NOT change the total amount of peptide in the vial — it only changes how concentrated the solution is.
reconstitution
Concentration Math — Calculating Your Dose
💡 Tips
THE EASY WAY: Most people use 2mL of BAC water per vial regardless — this is the community standard. With a 10mg vial + 2mL BAC, each 10 units on your syringe = 500mcg. With a 5mg vial + 2mL BAC, each 10 units = 250mcg. These are the most common dose increments so the math works out clean. For GLP-1 peptides (semaglutide, tirzepatide) which require very precise titration, consider using more BAC water (e.g., 3-5mL) so each unit represents a smaller increment.
Have a specific peptide question? Ask in the chat →