Vial in one hand, syringe in the other?Know the exact tick mark to draw to.
Three numbers - your vial size, the water you added, and the dose your provider gave you - and you get the exact mark to fill your syringe to. No converting milligrams in your head, no second-guessing the water, no sign-up. Just the number.
Uses the U-100 insulin-syringe standard (100 units = 1 mL). The dose stays yours - we only do the conversion.
= 0.1 mL on a U-100 syringe
Tired of doing pharmacy math over the kitchen sink?
This tool does the measuring math. The part that actually matters - whether a peptide fits your goals, the right dose, and proper monitoring - is a clinician's call. HEXIS providers prescribe it, dose it, and follow up, so you are not the one guessing with a vial and a syringe.
Free consult. Physician-guided. No card to book.
For education only — not medical advice. This tool does not diagnose any condition and is not a substitute for a physician. Results are general estimates based on screening tools and published research; your individual situation varies. Only a licensed clinician can interpret your labs and recommend treatment. Never start, stop, or adjust any medication without medical supervision.
How to calculate a peptide dose
To calculate a peptide dose you need two numbers. First, the concentration of your reconstituted vial: divide the peptide amount by the bacteriostatic water you added. A 5 mg vial (5,000 mcg) plus 2 mL of water makes 2,500 mcg per mL. Second, the draw volume: divide your prescribed dose by that concentration. A 250 mcg dose divided by 2,500 mcg/mL is 0.1 mL. On a U-100 insulin syringe, where 1 mL equals 100 units, 0.1 mL equals 10 units - so you draw to the 10-unit mark. Change the water and the unit reading changes: the same 250 mcg dose in a vial mixed with 1 mL of water (5,000 mcg/mL) would be 5 units instead. The dose itself always comes from your prescribing clinician; this tool only converts it into a measurement.
- 1Convert the vial to micrograms. If the vial is labeled in mg, multiply by 1,000. A 5 mg vial holds 5,000 mcg.
- 2Find the concentration. Divide the vial's micrograms by the mL of bacteriostatic water you added. 5,000 mcg in 2 mL = 2,500 mcg per mL.
- 3Find the draw volume. Divide your prescribed dose by the concentration. A 250 mcg dose in a 2,500 mcg/mL solution = 0.1 mL.
- 4Convert mL to syringe units. Multiply the draw volume by 100 (U-100 syringe). 0.1 mL = 10 units, so you fill to the 10-unit mark.
Research peptides usually ship as a lyophilized (freeze-dried) powder that has to be reconstituted - dissolved in bacteriostatic water - before it can be drawn into a syringe. The two questions everyone hits are "how much water do I add?" and "how many units do I draw?" Both come down to a single idea: concentration. Concentration is just the peptide mass divided by the liquid volume, measured in micrograms per milliliter (mcg/mL).
The amount of water you add is a choice, not a fixed rule. Any volume works as long as the powder dissolves and the vial holds it - more water simply makes each dose a larger, easier-to-measure draw, and less water makes a smaller one. A common approach is to pick a water volume that makes your prescribed dose land on a round number of syringe units. That is exactly what the slider-free input above lets you test: change the water amount and watch the units update live.
Drawing the dose is the second step. Once you know your concentration, the draw volume is your dose divided by that concentration. Insulin syringes are marked in "units" rather than mL, and the U-100 standard means 100 units fill 1 mL, so every 0.01 mL is one unit. Multiply your draw volume in mL by 100 and you have the unit mark to fill to. This calculator does all of it - mg to mcg, mass over volume, mL to units - so you are reading a number off a syringe, not doing algebra over a sink.
One thing this tool deliberately does not do is tell you what to take. It never picks a peptide, never suggests a dose, and never sets a schedule. Those are clinical decisions. It assumes you already have a prescription and a dose from a licensed provider, and it simply turns that dose into a measurement you can draw with confidence. If you do not have a provider guiding your peptide therapy, that is the real first step - well before any vial.
Common questions
How do you calculate peptide reconstitution?
Reconstitution is two pieces of arithmetic. First, find the concentration: divide the peptide amount in the vial by the amount of bacteriostatic water you add. For example, a 5 mg (5,000 mcg) vial mixed with 2 mL of water gives 2,500 mcg per mL. Second, find the draw volume: divide the dose your provider prescribed by that concentration. A 250 mcg dose from a 2,500 mcg/mL solution is 0.1 mL, which reads as 10 units on a U-100 insulin syringe. This calculator does both steps for you and shows the exact units to draw. It does not recommend a dose - the dose is a number you get from your provider.
How many units is a peptide dose on an insulin syringe?
On a standard U-100 insulin syringe, 100 units equals 1 mL, so 1 unit equals 0.01 mL. To convert a dose to units, first work out your concentration in mcg per mL, divide your dose by that concentration to get the volume in mL, then multiply by 100. Example: at 2,500 mcg/mL, a 250 mcg dose is 0.1 mL, and 0.1 mL times 100 equals 10 units. The unit reading depends entirely on how much water you reconstituted with, which is why this tool asks for your water volume.
How much bacteriostatic water should I add to a peptide vial?
There is no single correct amount - the water volume just sets how concentrated the solution is, and any volume works mathematically as long as the powder fully dissolves and the vial holds it. More water makes each dose a larger, easier-to-measure draw; less water makes a smaller draw. Many people choose a water amount that makes their prescribed dose land on an easy round number of units. This calculator lets you try different water volumes and instantly see the resulting concentration and unit reading. The right reconstitution and dose for you should be confirmed with your prescribing clinician.
How do I convert mg to mcg for peptides?
One milligram (mg) equals 1,000 micrograms (mcg). So a 5 mg vial contains 5,000 mcg, a 10 mg vial contains 10,000 mcg, and a 2 mg vial contains 2,000 mcg. To go the other way, divide micrograms by 1,000: a 500 mcg dose is 0.5 mg. Peptide vials are usually labeled in mg while doses are often described in mcg, so this conversion comes up constantly - the calculator handles it automatically and also has a dedicated mg/mcg converter.
Is this peptide calculator a substitute for medical advice?
No. This is a unit-conversion and measurement tool, not medical advice. It performs the same arithmetic a pharmacist would, using numbers you enter - your vial size, your water volume, and the dose your provider prescribed. It does not tell you what peptide to use, what dose to take, how often to inject, or whether a peptide is appropriate for you. Those are decisions only a licensed clinician can make. At HEXIS Health, a provider prescribes, doses, and monitors any peptide therapy.