FAQ - peptides & dosing

Peptides are highly potent, so a wrong dose can reduce effectiveness or increase side effects. The calculation matters because tiny volume differences translate into large dose differences. The calculator removes the risk of human arithmetic errors and keeps the maths reproducible.

Bacteriostatic water contains about 0.9 % benzyl alcohol, which inhibits bacterial growth in an opened vial. It matters because it lets you store a reconstituted vial for several uses. Never use tap water or boiled water for injections.

Choose a practical amount: not too little (dissolves poorly, stings) and not too much (injection volume too large). For standard vials (5–10 mg), 2–3 ml is a proven default. More water lowers the concentration, so you draw up a larger volume for the same dose.

Yes. More water lowers the concentration, so you draw up a larger volume for the same dose; less water does the opposite. Adjust the calculation accordingly - the calculator does this automatically once you change the water volume.

A peptide calculator works out the exact liquid volume you need to draw up to inject a given dose. Because peptides ship as a powder (lyophilisate), you first mix them with bacteriostatic water (BAC). The calculator removes the guesswork from converting milligrams of powder into millilitres on the syringe.

Volume to draw up (ml) = (target dose ÷ vial strength) × BAC water added. Example: 250 mcg target, 5 mg (5000 mcg) vial, 2 ml water → (250 ÷ 5000) × 2 = 0.1 ml. On a U100 syringe, 0.1 ml = 10 units (IU). This formula always converts your target dose into a volume you can read on the syringe.

Use U100 insulin syringes. 100 units equal exactly 1 ml, so 0.1 ml is 10 IU. What counts is matching your reading to the scale: check whether your syringe is marked in IU or in ml before drawing up.

Store the mixed solution refrigerated (2–8 °C) and usually use it within about 21–30 days. Lyophilised powder keeps far longer when frozen. Protect it from light to preserve potency.

BAC water (bacteriostatic water) contains 0.9 % benzyl alcohol as a preservative that inhibits bacterial growth, allowing multiple withdrawals from the same vial for up to 28 days after first puncture. Sterile water, by contrast, contains no preservative and must be discarded after a single use - it is not suitable for multi-dose applications.

The benzyl alcohol in BAC water is bacteriostatic (growth-inhibiting), not bactericidal (killing). Strict aseptic technique is therefore essential: always swab the rubber stopper with an alcohol wipe before each puncture, use a sterile needle and syringe, and store the vial refrigerated (2–8 °C) after opening. Cloudiness, particles, or discoloration are warning signs - discard the vial immediately.

A common misconception: BAC water does not extend the shelf life of the peptide itself; it only protects against microbial contamination during repeated access. The peptide's chemical stability depends on factors like temperature, light, and pH. See our FAQ on storing reconstituted peptides for more details.