How do I calculate peptide dosage for a syringe?
Use the Peptide Calculator below — enter your vial amounts, and click Calculate.
What is a Peptide Calculator?
A peptide calculator is an essential tool for researchers and individuals using reconstituted peptides. Because peptides typically arrive as a lyophilized (freeze-dried) powder in a vial, they must be mixed with a diluent—most commonly Bacteriostatic Water—before they can be drawn into a syringe and administered. The peptide calculator takes the guesswork out of the math, helping you convert milligrams (mg) and micrograms (mcg) — much like tracking your nutrition with our Macros Calculator or Protein Calculator — into precise syringe units based on the total volume of your insulin syringe.
How to Use the Peptide Reconstitution Calculator
- Select your syringe size: U-100 syringes are the most common and contain 100 units per 1 ml. If you use a 0.5 ml (50 unit) or 0.3 ml (30 unit) syringe, select accordingly.
- Enter the peptide amount: Check your vial's label to see how many milligrams (mg) of peptide it contains (e.g., 5mg, 10mg).
- Enter Bacteriostatic water added: Input the amount of liquid (in ml) you added to the vial for reconstitution. 1ml or 2ml are standard amounts.
- Enter your desired dose: Input the exact dose you wish to draw. Be careful with units—many protocols use micrograms (mcg). Remember that 1,000 mcg equals 1 mg.
- Calculate: The calculator will tell you exactly how many tick marks (units) to draw on your syringe.
Converting mcg to mg
A common point of confusion is the conversion between milligrams and micrograms. When using a peptide dosage calculator, ensure you enter the correct unit. Our calculator can help you convert milligrams (mg) — just as our Calorie Calculator helps you hit precise macro goals — effortlessly.
- 1 milligram (mg) = 1,000 micrograms (mcg)
- 0.5 mg = 500 mcg
- 0.25 mg = 250 mcg
Common Peptide Dosage Examples
| Peptide | Vial Size | Bac Water Added | Desired Dose | Syringe Units (U-100) |
|---|---|---|---|---|
| Semaglutide | 5 mg | 2 ml | 0.25 mg | 10 units |
| Tirzepatide | 10 mg | 1 ml | 2.5 mg | 25 units |
| BPC-157 | 5 mg | 2 ml | 250 mcg (0.25mg) | 10 units |
| Ipamorelin/CJC-1295 | 5 mg | 2 ml | 300 mcg (0.3mg) | 12 units |
FAQ
The amount of bac water (bacteriostatic water) to add depends on the vial size and your desired concentration. Commonly, 1 ml or 2 ml is added to a 5 mg or 10 mg vial. Adding more water dilutes the mixture, requiring a larger volume (more units) to be drawn for the same dose, which can make tiny doses easier to measure accurately.
Insulin syringes are typically marked in "Units" rather than milliliters (ml). A standard U-100 insulin syringe holds 1 ml of liquid, which corresponds to 100 units. Therefore, 1 unit equals 0.01 ml. Our peptide dosing calculator assumes you are using standard U-100 insulin syringes.
If you have a 5mg vial of Semaglutide and add 2ml of bacteriostatic water, the concentration is 2.5mg per ml. If your starting dose is 0.25mg, you need 0.1ml of the solution. On a U-100 syringe, 0.1ml is exactly 10 units. You can input these values into the semaglutide reconstitution calculator above to verify.
If you believe you have administered an incorrect dose, it is crucial to consult with a healthcare professional immediately. Accurate measurement is critical when using peptides to avoid potential side effects.
It is generally recommended to use bacteriostatic water, which contains a small amount of benzyl alcohol to inhibit bacterial growth. Sterile water for injection lacks this preservative, meaning any reconstituted peptide solution must be used immediately and cannot be safely stored for later use.
The shelf life of a reconstituted peptide depends on the specific peptide and storage conditions. Generally, keeping them refrigerated (2-8°C) and protected from light helps maintain stability. Always check the specific recommendations for your product.
Free Online Calculators
Fitness & Health
Peptide Quick Facts
- Always swab the vial top with alcohol before drawing.
- Store reconstituted peptides in the refrigerator (2-8°C).
- Do not shake the vial vigorously; roll it gently to mix.
- Keep peptides away from direct sunlight.