The 8 steps
- 1
Gather your supplies
You need the lyophilized peptide vial, a vial of bacteriostatic water (BAC water), a U-100 insulin syringe (typically 1 mL with 100 unit markings), and an alcohol swab. Work on a clean surface in a low-traffic area.
- 2
Calculate the BAC water volume
Use the Peptides Calculator reconstitution calculator above to decide how much BAC water to add. Common volumes are 1 mL, 2 mL, or 3 mL per vial — more water means each unit on the syringe represents less peptide, which can be easier to dose accurately for small amounts.
- 3
Swab both vial tops
Wipe the rubber stopper of both the BAC water vial and the peptide vial with an alcohol swab. Let them air-dry for a few seconds.
- 4
Draw the BAC water
Pull the calculated volume of BAC water into the insulin syringe by inserting the needle through the rubber stopper and pulling back the plunger. Tap out any air bubbles before withdrawing the needle.
- 5
Add BAC water to the peptide vial slowly
Insert the needle into the peptide vial at a 45° angle so the BAC water runs down the inside wall rather than splashing onto the dry peptide cake. Push the plunger slowly. Aggressive injection can denature delicate peptides like BPC-157 or TB-500.
- 6
Swirl, do not shake
Gently swirl the vial in circles until the peptide powder fully dissolves. Never shake — vigorous agitation can fragment the peptide and reduce potency. Most peptides dissolve within 30 seconds; if it takes longer, leave the vial in the fridge for 5-10 minutes and check again.
- 7
Draw your dose using the calculator
Use the calculator to convert your target dose (in mg or mcg) into syringe units, then draw to that line. The visual syringe overlay in the Peptides Calculator app shows you exactly where the fill line should be.
- 8
Refrigerate the reconstituted vial
Once reconstituted, store the vial in the refrigerator (36-46°F / 2-8°C). Most peptides stay stable for 4-8 weeks reconstituted. The benzyl alcohol in BAC water prevents bacterial growth during that window.
Common mistakes to avoid
Shaking the vial
Shaking can mechanically fragment the peptide. Always swirl gently.
Using sterile water instead of BAC water
Plain sterile water has no preservative — your reconstituted vial will spoil within 24 hours. Always use bacteriostatic water for multi-use vials.
Eyeballing the dose
Insulin syringes have very small unit markings — guessing leads to under- or over-dosing. Use the calculator and confirm with the visual syringe overlay.
Storing at room temperature
Most peptides degrade quickly at room temp once reconstituted. Refrigerate immediately after mixing.
Frequently asked questions
How long does a reconstituted peptide vial last?
Most peptides remain stable for 4 to 8 weeks in the refrigerator after reconstitution with bacteriostatic water. Some delicate peptides (e.g. some growth-factor peptides) are stable for shorter windows; always check the specific peptide profile in the Peptides Calculator app for guidance.
Do I need to filter or sterilize after reconstituting?
For self-administered reconstitution at the bench, no. Bacteriostatic water already contains 0.9% benzyl alcohol that prevents bacterial growth. Always work with clean hands, alcohol-swab vial stoppers, and use a fresh sterile needle for every draw.
Can I reconstitute two peptides in the same vial?
Some users prepare peptide blends. Whether two peptides are compatible depends on their chemistry — common stacks like BPC-157 + TB-500 are well documented; others may not mix cleanly. The Peptides Calculator stack builder helps model timing and dosing for multi-peptide protocols.
What if my peptide does not fully dissolve?
Refrigerate the vial for 10-15 minutes and gently swirl again. Some peptides are slow to go into solution. If a small undissolved fragment remains after 30 minutes, gently rotate the vial — never heat or shake.