How much water should I add?
This guide does not choose a volume. More liquid lowers mcg per unit and can make a small mass easier to read on the syringe. That is a readability note.
How-to · reviewed 2026-10-09
How to mix a freeze-dried peptide (math only)
Mixing a vial means dissolving a labeled powder into a liquid volume you choose. Concentration is mass divided by volume. A U-100 syringe has 100 marks per milliliter, so units equal milliliters times 100. This guide explains that math. It does not tell you to use a compound or how much to take. Read the label. If a seller title, a forum post, and a calculator all disagree, keep the printed mass and the volume you actually added and ignore the rest.
What the vial label is telling you
A freeze-dried vial lists a mass, usually in milligrams. That number is what the seller printed. It does not prove purity. It does not set a clinical amount. If a test report exists, read it as a report for that lot.
Powder takes almost no space next to the liquid you add. On this site, concentration uses the liquid volume you type. The powder’s own volume stays out of the math.
The only equation
Concentration (mcg per mL) = vial milligrams × 1000 ÷ liquid milliliters.
Volume to draw (mL) = the mass you want to measure (mcg) ÷ concentration.
U-100 units = volume in mL × 100. If you use a different scale, replace 100 with that scale’s marks per mL.
Worked example with invented inputs so you can see the algebra. 10 mg in 2 mL is 5000 mcg/mL. Measuring 250 mcg is 0.05 mL, which is 5 units on U-100. Change any input and the outputs change. Try it.
What this guide refuses
It will not pick bacteriostatic versus sterile water for you. That is a product-label and clinician question.
It will not tell you to aim for a “typical” amount. Competitor pages often bury a recommended dose under a calculator. PepBear’s calculators stay blank until you type.
Questions
What does “keep the smallest measured amount at 5 units or more” mean?
Below about 5 units on a U-100 barrel, the mark is easy to misread. That is a measuring warning. The page does not set a minimum amount.
Sources
Next: BPC-157 calculator or coach weekly review.
These guides explain records and arithmetic. Not medical advice. PepBear does not pick a dose, a cycle, or a seller.