What reconstitution is
Peptides ship as a lyophilized (freeze-dried) powder — stable for a long time, but too dry to measure into small doses. Reconstituting just means dissolving it back into a liquid with a measured amount of water.
Always use bacteriostatic water (BAC water): sterile water with a trace of benzyl alcohol that stops bacteria growing once the vial is mixed. Never tap, distilled, or bottled water.
The amount of powder never changes — a 5 mg vial always contains 5 mg. What you choose is how much water to add. More water makes a weaker, easier-to-draw liquid; less water makes a stronger, more concentrated one.
What you need
- The peptide vial — a small glass bottle with a rubber top, holding the dry powder.
- Bacteriostatic water — in its own vial.
- A reconstitution syringe — a larger syringe (often 1–3 mL) to move the water into the vial.
- Insulin syringes — small U-100 syringes for drawing each dose. "U-100" means the syringe is marked in units where 100 units equals 1 mL. (See the glossary.)
- Alcohol wipes — to clean the rubber tops before the needle goes in.
How much water to add
There is no single "correct" amount of water. It is a trade-off you control:
- More water → the liquid is more dilute, so each dose is a larger, easier-to-see volume on the syringe. Good when your doses are very small.
- Less water → the liquid is more concentrated, so each dose is a smaller volume. Good when you want the vial to last many doses.
A common, easy starting point is to add enough water that a round dose lands on a round number of units. The calculator exists so you don't have to guess: put in the numbers and it tells you the draw. As a rule of thumb, aim for a draw of at least a few units — anything under 2 units is very hard to measure by eye.
The steps
Click through the five steps — one at a time, so it never feels like a wall of text.
Bring both vials to room temperature
Let cold vials sit out a few minutes. Wipe each rubber top with an alcohol swab and let it dry.
Draw the bacteriostatic water
Pull your chosen amount into the mixing syringe — say 2 mL. That number is up to you; the calculator helps you pick.
Add it down the inside of the glass
Aim the water at the vial wall, not straight onto the powder, and let it run slowly. A hard jet can damage the peptide.
Swirl gently — never shake
Roll it slowly or just wait; it dissolves on its own. Shaking foams it and breaks the peptide down — the single most common way to ruin a vial.
Check it's clear
A good mix is clear and colourless with nothing floating. Cloudy, coloured, or specks? Don't use it — see signs of degradation.
Drawing a dose
Once the vial is mixed, each dose is drawn with a small U-100 insulin syringe. You don't measure the dose in milligrams directly — you measure it as a number of units on the syringe, which corresponds to a tiny volume of liquid.
Wipe the vial top, push the needle in, turn the vial upside down, and pull the plunger to the unit line the calculator gave you. Tap out any air bubbles and push them back into the vial, then re-draw to the exact line. That's the dose.
Use the calculator to turn your dose into a unit line. For example: a 5 mg vial mixed with 2 mL of water, at a 250 mcg dose, works out to 0.1 mL — which is 10 units on a U-100 syringe.
Common mistakes
- Shaking to "help it dissolve." It dissolves on its own. Shaking damages it.
- Using the wrong water. Only bacteriostatic water. Not sterile saline, not tap, not distilled.
- Blasting water onto the powder. Aim down the glass wall instead.
- Doses under 2 units. Too small to measure by eye — add less water next time so the same dose lands on a larger unit line.
- Leaving the mixed vial out. Once reconstituted, it belongs in the fridge. See the storage guide.