Peptide reconstitution calculator.
Concentration and U-100 syringe units from your numbers. Enter what is on the vial label, how much bacteriostatic water you add, and the amount you want to measure. The page converts the units and shows every step of the math, in plain language.
1 mg = 1000 mcg
Amounts must be above zero.
Your numbers stay in your browser and are saved only on this device, so they are still here when you come back. Nothing you type is uploaded.
Standard 1 mL U-100 insulin syringe. 100 units = 1 mL.
Fill in all three fields and the conversion appears here, with each step of the math written out.
- Volume to draw
- Concentration
What the calculator works out.
The fields above start empty on purpose: the only numbers that are true are the ones on the vial in front of you. Here is the same arithmetic worked through on one concrete case, so you can see what the tool does before you enter anything.
A 10 mg vial reconstituted with 2 mL of bacteriostatic water gives 5 mg/mL. An amount of 0.5 mg is 0.5 ÷ 5 = 0.1 mL, which reads 10 units on a U-100 syringe.
10 mg in 2 mL = 5 mg/mL → 0.5 mg dose = 0.1 mL = 10 units
Common vial and water pairs
Concentration is the vial mass divided by the water added. Nothing here is a recommendation about how much water to use or how much to take: it is what the arithmetic produces for a pairing you already have.
| Vial and water | Concentration | 1 unit holds | 20 units | 40 units |
|---|---|---|---|---|
| 5 mg in 1 mL | 5 mg/mL | 0.05 mg | 1 mg | 2 mg |
| 5 mg in 2 mL | 2.5 mg/mL | 0.025 mg | 0.5 mg | 1 mg |
| 10 mg in 2 mL | 5 mg/mL | 0.05 mg | 1 mg | 2 mg |
| 10 mg in 3 mL | 3.333 mg/mL | 0.033 mg | 0.667 mg | 1.333 mg |
| 10 mg in 5 mL | 2 mg/mL | 0.02 mg | 0.4 mg | 0.8 mg |
| 15 mg in 3 mL | 5 mg/mL | 0.05 mg | 1 mg | 2 mg |
| 20 mg in 2 mL | 10 mg/mL | 0.1 mg | 2 mg | 4 mg |
| 30 mg in 3 mL | 10 mg/mL | 0.1 mg | 2 mg | 4 mg |
| 50 mg in 5 mL | 10 mg/mL | 0.1 mg | 2 mg | 4 mg |
Educational unit conversion only. This page converts numbers you already have and does not tell you how much water to add, how much to take, or how often. Those are decisions for the clinician who wrote your prescription.
Three steps, no mystery.
The calculator runs exactly this chain, in this order, and prints the whole thing under the result so you can check every step by hand.
Concentration
Divide the peptide amount by the water you add. That is the strength of every mL of the finished solution.
mg in vial ÷ mL of water = mg/mL
Example: 10 mg in 2 mL = 5 mg/mL
Volume
Work in mg. If your amount is in mcg, divide it by 1000 first. Then divide the amount by the concentration to find the volume that holds it.
amount in mg ÷ mg/mL = mL
Example: 0.5 mg ÷ 5 mg/mL = 0.1 mL
Syringe units
A U-100 syringe is marked at 100 units per mL, so multiply the volume by 100 to read the same amount on the barrel.
mL × 100 = units
Example: 0.1 mL × 100 = 10 units
Rounding matches the Protocol Her app exactly: numbers in the chain are shown to at most three decimal places, and the unit result to one decimal place. A positive result under 0.05 units shows as <0.1, and anything over 10,000 shows as >10,000.
Unit conversion, answered.
How many units are in 1 mL on a U-100 insulin syringe?
100. U-100 means the scale is marked at 100 units per mL, so 1 mL = 100 units, 0.5 mL = 50 units, and 0.1 mL = 10 units. Units and mL are two readings of the same volume, related by a factor of 100.
How do I convert mg to mcg for peptides?
1 mg equals 1000 mcg. Multiply mg by 1000 to get mcg, and divide mcg by 1000 to get mg. For example, 250 mcg is 0.25 mg, and 5 mg is 5000 mcg. The calculator accepts either unit and converts for you.
Does adding more bacteriostatic water change the amount of peptide?
No. The vial still holds the same total mg. More water lowers the concentration (mg per mL), so the same amount of peptide occupies more mL, and therefore more units, on the syringe. Less water does the opposite. The water amount changes how an amount is measured, not what it is.
What does reconstitution mean?
Reconstitution is dissolving a freeze-dried (lyophilized) peptide powder in a liquid, usually bacteriostatic water, so it can be measured with a syringe. This calculator does not suggest how much water to add or how much to take. It only converts the numbers you enter between mg, mcg, mL, and U-100 syringe units.
The same calculator, plus the tracking.
Protocol Her puts this reconstitution calculator on your iPhone with a live syringe gauge, next to private tracking for doses, cycles, symptoms, and labs. Free to download. No account, and your health data stays on your phone.
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