How to Use the Peptide Reconstitution Calculator
Our free peptide dosage calculator takes the guesswork out of preparing peptides. Whether you are working with a single peptide or a multi-peptide blend, the calculator handles all the math and shows you exactly where to draw on your syringe.
Start by choosing your syringe size, entering the peptide vial amount in milligrams, and specifying how much bacteriostatic water you have added (or plan to add). Then enter your desired dose in micrograms. The calculator instantly shows you the number of syringe units to draw, the solution concentration, and how many doses you will get from the vial.
Understanding Peptide Reconstitution
Peptides are shipped as freeze-dried (lyophilized) powders that need to be mixed with a liquid before use. This process is called reconstitution. The most common liquid used is bacteriostatic water, which contains a small amount of benzyl alcohol to prevent bacteria from growing in the solution.
The amount of water you add directly affects the concentration. For example, adding 1 mL of water to a 5 mg vial creates a concentration of 5 mg/mL (or 5,000 mcg/mL). Adding 2 mL to the same vial cuts the concentration in half to 2.5 mg/mL. A lower concentration means you draw more liquid per dose, which can make it easier to measure small doses accurately.
How to Properly Add BAC Water to a Peptide Vial
When reconstituting, always aim the stream of bacteriostatic water against the glass wall of the vial — never squirt it directly onto the powder. Let the liquid slide down and gently dissolve the peptide. Once the water is in, tilt and swirl the vial slowly. Avoid shaking or vortexing, as this can damage the peptide structure and reduce effectiveness.
Syringe Units Explained
Insulin syringes are marked in "units" rather than milliliters, which can be confusing at first. The relationship is straightforward: on a U-100 syringe, 100 units equals 1 mL. Here is how the most common syringe sizes break down:
- 0.3 mL syringe — 30 units total, each unit = 0.01 mL
- 0.5 mL syringe — 50 units total, each unit = 0.01 mL
- 1.0 mL syringe — 100 units total, each unit = 0.01 mL
Smaller syringes offer more precise measurements for low-volume doses. If your calculated dose falls between tick marks, a 0.3 mL syringe may give you better accuracy than a 1.0 mL syringe.
Multi-Peptide Blends
Some peptides are commonly combined in a single vial for convenience. Popular blends include BPC-157 with TB-500 for recovery, and CJC-1295 with Ipamorelin for growth hormone support. When peptides are blended in one vial, every draw contains a fixed ratio of all peptides — you cannot dose them independently.
Our blend calculator handles this by letting you set a target dose for one peptide and automatically calculating how much of every other peptide you will receive in the same draw. This ensures you always know exactly what is in each injection.
Storage and Shelf Life
Unreconstituted (powder) peptides are quite stable. Store them in a cool, dry place — ideally in a freezer at -20°C for long-term storage. At room temperature, most lyophilized peptides remain stable for several weeks.
Once you add bacteriostatic water, the clock starts. Refrigerate the reconstituted vial at 2–8°C and use it within 3 to 4 weeks. Do not freeze and thaw the same vial repeatedly, as this degrades the peptide. If you will not use the entire vial within that window, consider splitting it into smaller portions (aliquots) before freezing.
Common Reconstitution Mistakes
The most frequent errors involve using the wrong type of water (tap or distilled instead of bacteriostatic), shaking the vial aggressively, and leaving reconstituted peptides at room temperature. Each of these can reduce the effectiveness of the peptide or introduce contamination. Always use sterile bacteriostatic water, handle the vial gently, and refrigerate immediately after reconstitution.