Measures accurately; does not recommend doses. Dosing decisions belong with your prescriber.
How to reconstitute peptides, step by step
This peptide reconstitution calculator does the math, but here is how the actual mixing works. Reconstituting peptides is less like chemistry class and more like a very precise, very tiny baking recipe. The peptide dosing calculator above tells you exactly how much water to add and how many syringe units to draw for your peptide dose.
- A mixing syringe (typically 3mL with a long needle)
- An insulin syringe for your dose (typically 0.3mL, 0.5mL, or 1mL)
- Bacteriostatic water
- Alcohol pads
- Your peptide vial
Prep your space. Wipe down your surface with an alcohol pad and wash your hands. Don't make it weird, just make it clean.
Pop the plastic caps off your peptide vial and the BAC water vial. Use a fresh alcohol pad to wipe the rubber stopper on each one.
Use your larger mixing syringe to draw up the correct amount of BAC water. The calculator above tells you exactly how much this is.
Gently push the needle through the center of your peptide vial's stopper. Angle the needle so the water runs down the inside wall of the glass, not straight onto the powder. This protects the peptide.
Once all the water is in, remove the syringe. Swirl the vial gently or roll it between your hands until all the powder is dissolved. Never shake it.
That's it. Your vial is prepped. Store it in the fridge, and it's ready for your first dose.
What if I added too much water?
It's fine. It just means your peptide is more diluted, so you'll need to draw up more units to get your dose. Just redo the math or use the calculator again with the new water amount.
What if my vial went cloudy?
If it's cloudy right after mixing, you might have shaken it or shot the water directly onto the powder. Let it sit in the fridge for a few hours. If it's still cloudy or has floaters, the vial is likely compromised and shouldn't be used.
The peptide dosing formula, explained
This is the formula behind every peptide mixing calculator. It figures out how many units on your syringe equals the peptide dose you want.
Dose (mcg) ÷ Concentration (mcg per unit) = Units to draw
Here are a few common examples worked out.
Syringe units to mcg: the conversion table
Every standard insulin syringe is marked with 100 units, which equals exactly 1 milliliter (mL) of liquid. This table shows how many micrograms (mcg) of peptide you get based on the units you draw at a few common concentrations.
(5mg + 2mL)
(5mg + 1mL)
(10mg + 2mL)
How much water, and why it is usually 2 mL
The water does not change the dose. It changes how much of the syringe the dose takes up.
More water means a longer, easier-to-read draw and more injection volume; less water means a shorter draw and a sharper sting. For a 5 mg vial, 2 mL puts most common doses between 5 and 20 units on a 50-unit syringe, which is the readable middle. Use bacteriostatic water, not sterile water: the 0.9% benzyl alcohol is what lets an opened vial last 4 to 6 weeks in the fridge.
Three sizes, three tick spacings
Widest ticks. Best for small draws under 30 units.
The default in most kits. Readable middle for 5–20 unit doses.
Tightest ticks. Needed for GLP-1 doses over 50 units.
The marks are units, not millilitres. 100 units is 1 mL on every U-100 syringe, whatever its size. Smaller barrels do not hold less per unit; they just stop sooner and spread the ticks further apart so small draws are easier to read. If your dose lands between two ticks, change the water, not the dose.
Bacteriostatic water vs sterile water: which one and why
0.9% benzyl alcohol preserves an opened vial.
No preservative. Rare for peptides.
Bacteriostatic water is sterile water with a tiny amount (0.9%) of benzyl alcohol added. That alcohol acts as a preservative, preventing any bacteria from growing in the vial after you've punctured the stopper. This is why you can use a multi-dose vial for up to 28 days after mixing.
Sterile water is just that: sterile, with no preservative. You'd only use it for a single-dose injection where you use the entire vial at once, which is rare for peptides. For any protocol where you're drawing multiple small doses over weeks, you should always use bacteriostatic water.
Once opened, your BAC water and your mixed peptide vial should be kept in the fridge. An unopened vial of BAC water can be stored at room temperature, away from light. Always check the expiration date on the vial before you use it.
GLOW, KLOW and what one line actually delivers
A blend vial is several peptides freeze-dried together at fixed amounts. The maths is the same as a single peptide: the vial's total mg over the water gives the concentration, and each component rides along in proportion. Where people go wrong is dosing a 70 mg GLOW vial as if it were 70 mg of one thing. Pick the blend chip above and the result splits the draw into its parts so you can check each against the profile page.
Most popular peptides
Full profiles with dosing, side effects, and what to expect.