Peptide Calculator
Compute precise draw-up volumes for research peptide injections
Result
For a dose of 100 mcg
Draw to 2.0 units
Doses / vial
100
Days of supply
100
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What Is Peptide Reconstitution?
Peptide reconstitution is the process of dissolving freeze-dried peptide powder in bacteriostatic water to create a liquid solution. Peptides are shipped as dry powder because they degrade quickly in liquid form. This step must be completed before use and is essential for accurate measurement and dosing.
The amount of bacteriostatic water added changes the solution's concentration. That concentration determines how much liquid to draw into the syringe for each dose. Less water means each unit on the syringe contains more peptide. More water means each unit contains less. Most people use 1 ml or 2 ml.
The calculator above handles this math automatically. Enter the peptide vial size, the amount of bacteriostatic water, and the target dose. The calculator shows exactly how many units to draw on the syringe.
Step-by-Step Reconstitution Guide
Gather Your Supplies
You will need the peptide vial, bacteriostatic water, an insulin syringe for reconstitution, and a separate insulin syringe for injection. Alcohol swabs for sterilizing vial tops are also recommended.
Determine Your Water Volume
Use the calculator above to plan how much bacteriostatic water to add. Common volumes are 1 ml or 2 ml. More water means a more dilute solution and easier measurement of small doses. Less water means a more concentrated solution and fewer injections for larger doses.
Add Water Slowly
Draw the planned amount of bacteriostatic water into a syringe, then inject it into the peptide vial. Aim the stream down the inside wall of the vial — do not spray directly onto the powder, as this can damage the peptide.
Let It Dissolve
Gently swirl the vial until the powder is fully dissolved. Do not shake vigorously — peptides are fragile molecules that can denature with excessive agitation. The solution should be clear with no visible particles.
Calculate Your Draw Volume
Use the calculator result to determine how many units to draw for your desired dose. For example, if your result is 5.0 units, draw to the 5-unit mark on your insulin syringe.
Vial Types & Sizes
Reconstitution involves two vials. The peptide vial (left) is a small 2–3 ml glass vial containing freeze-dried powder. The label indicates how many milligrams are inside — typically 5 mg, 10 mg, or 15 mg. That's the number to enter for "Peptide Vial Quantity" in the calculator.
The bacteriostatic water (right) is a separate, larger vial (10 ml or 30 ml). A chosen amount is drawn from it and injected into the peptide vial. More water = more dilute = easier to measure small doses. Less water = more concentrated. Most people add 1–2 ml, but the vial will hold up to 3.
The amount of water added determines the concentration of the solution, which in turn determines how many units on the syringe correspond to the target dose. The calculator above handles this math automatically.
Insulin Syringe Sizes & Markings
Insulin syringes measure volume in "units" rather than milliliters. One unit equals 0.01 ml. Three sizes are available:
- 0.3 ml — holds 30 units
- 0.5 ml — holds 50 units
- 1.0 ml — holds 100 units
The smaller the syringe, the more precise the measurement. The tick marks on a smaller barrel are spaced further apart, making it easier to read exact volumes. A 1.0 ml syringe works for most situations, but if the calculated dose is under 15 units, a 0.3 ml syringe will give the most accurate reading.
Frequently Asked Questions
How much bacteriostatic water should I add to a peptide vial?
There is no single correct answer — it depends on your desired dose and syringe size. Adding more water makes the solution more dilute, which can be helpful for measuring very small doses accurately. Adding less water makes it more concentrated. Common choices are 1 ml or 2 ml. Use the calculator above to see how different water volumes affect your draw amount.
What is the difference between bacteriostatic water and sterile water?
Bacteriostatic water contains 0.9% benzyl alcohol, which inhibits bacterial growth and allows the reconstituted peptide to be stored and used over multiple doses. Sterile water has no preservative and should only be used for single-use applications. For multi-dose peptide vials, always use bacteriostatic water.
How long does a reconstituted peptide last?
When reconstituted with bacteriostatic water and stored in the refrigerator (2-8°C), most peptides remain stable for 4-6 weeks. Some peptides degrade faster than others. Never freeze a reconstituted peptide solution, and always store it away from light.
How do I convert mcg to IU for peptides?
Micrograms (mcg) and International Units (IU) are different measurement systems. The conversion factor is peptide-specific — there is no universal formula. For growth hormone releasing peptides, dosages are typically expressed in mcg. For HGH and HCG, dosages are expressed in IU. Check the specific peptide's documentation for the correct conversion. Our beginner's guide covers common dosing conventions.
Next Steps
Learn to Reconstitute
Step-by-step walkthrough of mixing bacteriostatic water with lyophilized peptides, including technique tips and storage instructions.
Read GuideBuild a Full Protocol
Use our protocol tracker to schedule doses, track multiple peptides, and export your complete protocol as a PDF.
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