Peptide Reconstitution & Dosage Calculator
Drag the sliders to work out exactly how much bacteriostatic water to add and where to draw the syringe — matched to our own product range.
Quick-fill a product
Syringe size
Peptide quantity (per vial or pen)
10 mgBacteriostatic water added
2 mLDose per use
250 mcgHow the reconstitution formula works
Peptides ship as a freeze-dried (lyophilised) powder, not a ready-to-use liquid. Once you know three numbers — the mg on the label, the mL of bacteriostatic water you add, and your target dose — the rest is fixed arithmetic:
Example: a 5 mg quantity mixed with 2 mL of water gives a 2,500 mcg/mL solution. A 250 mcg dose is then 0.1 mL — 10 units on a standard U-100 insulin syringe.
Why the precision window matters
Most guides only warn you when a dose is too large for your syringe. The other failure mode gets missed just as often: a dose so small it only fills 1–2 units, which is nearly impossible to draw accurately by eye. As a rule of thumb, aim for a draw that lands between roughly 5 and 50 units on a standard 100-unit syringe — that’s the range where the markings give the most reliable read. The calculator checks both ends automatically once all four steps are filled in.
Mixing bacteriostatic water with your peptide
- Wipe both stoppers. Clean the rubber top of the bacteriostatic water vial and the peptide vial with an alcohol swab before inserting a needle into either.
- Draw the water first. Pull the calculated amount of water into the syringe before touching the peptide.
- Add it down the wall. Angle the needle at the inside glass rather than aiming straight at the powder, and push the water in slowly.
- Roll, don’t shake. Gently swirl or roll the vial between your hands until the solution runs clear. Shaking can damage some peptides.
- Label and refrigerate. Write the mix date on it and store it in the fridge, out of direct light, following the specific storage guidance for that product.
Reference: sizes across our range
| Product | Quantity | Example water | Shop |
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Click a row to load it into the calculator above. Exact mg and current stock live on each product page.
Blends and more from Peptides Pens
Blends contain more than one peptide, so enter the mg of the individual peptide you’re calculating for (see the FAQ below).
Browse everything in the full shop, or contact the team with a question about a product.
Frequently asked questions
Use the mg of the specific peptide inside the blend you’re dosing, not the combined total on the label. A 20 mg BPC‑157 + TB‑500 blend is 10 mg of each — enter 10 mg if you’re working out a BPC‑157 dose from it. Check each blend’s product page (for example Glow 70mg or BPC-157 + KPV + TB-500 30mg) or your Certificate of Analysis for the per-peptide amounts.
A draw can fit the barrel and still be too small to read accurately — a 1–2 unit dose is easy to misjudge on a 100-unit scale. The calculator flags draws outside the roughly 5–50 unit precision window so you can adjust your water volume before mixing.
There’s no single correct amount — it’s a trade-off between concentration and how easy the resulting dose is to read. More water dilutes the solution and spreads a given dose across more syringe markings; less water concentrates it into fewer units. The total peptide doesn’t change either way.
This varies by product, but reconstituted peptides are commonly usable for a few weeks when kept refrigerated at 2–8°C and protected from light. Always check the specific storage guidance for the product you’re using, and avoid freeze-thaw cycles once mixed.
Yes — that’s the purpose of a bacteriostatic (preservative-containing) diluent rather than plain water. Use a clean needle for each draw and swab the stopper with alcohol beforehand.
No. It performs reconstitution arithmetic for research and laboratory reference only. It doesn’t diagnose, treat, or recommend a dose for any condition. Always work from your product’s documentation and a qualified professional for anything beyond laboratory research use.