Free Peptide Dosage Calculator
Enter your vial size, bacteriostatic water volume, and target dose to instantly calculate the exact draw volume in milliliters. Pre-loaded with half-life and dosage data for 100+ research peptides including BPC-157, TB-500, Semaglutide, and Retatrutide — no signup required.
Dosing tools
Peptide Dosage Calculator
Calculate peptide doses with our visual syringe guide.
mg
Enter the total amount of peptide in the vial in milligrams (as stated on the label).
The dose you want to inject per administration, in mcg or mg.
1,000 mcg = 1 mg
1 mL
2 mL
3 mL
5 mL
Custom
Volume of bacteriostatic water you add to reconstitute the powder. Use BAC water for preservation.
Injection Results
Based on your vial and dilution inputs.
All peptides
SINGLE COMPOUNDVolume per injection
0.05
mL
Concentration
10.00
mg/mL
Doses per vial
20
doses
Total injections per vial
20 injections
How it works
Based on a 10 mg peptide vial diluted with 1 mL of bacteriostatic water, each 500 mcg injection equals 0.05 mL.
1mL / 100 units
5 units
0.050 mL
Reference Guide
Common Vial Sizes
| Peptide | Typical Size |
|---|---|
| BPC-157 | 5mg, 10mg |
| TB-500 | 5mg, 10mg |
| Semaglutide | 3mg, 5mg |
| Ipamorelin | 5mg, 10mg |
| CJC-1295 | 2mg, 5mg |
| Tirzepatide | 5mg, 10mg, 15mg |
Reconstitution Tips
- Use bacteriostatic water (BAC)contains 0.9% benzyl alcohol for preservation
- Inject water slowlyaim down the vial wall, not directly onto powder
- Never shakegently swirl or roll the vial until dissolved
- Store properlyrefrigerate at 2-8°C after reconstitution
- Use within 28 daysmost reconstituted peptides remain stable for about 4 weeks
- Keep sterilealways clean vial tops with alcohol before drawing
How peptide dosage is calculated
Every peptide dose follows the same three-variable formula: vial size in mg, reconstitution volume in mL, and target dose in mcg or mg. Understanding what each input means helps you catch errors before they reach the syringe.
Enter your vial size
Find the total peptide amount on the vial label and enter it in milligrams (e.g., 10 mg). This is the full quantity of peptide dissolved in your reconstituted solution. Common sizes are 5 mg and 10 mg.
Set your BAC water volume
Select or enter how much bacteriostatic water you used in milliliters — choose from 1, 2, 3, or 5 mL presets, or enter a custom amount. More water means a lower concentration and a larger draw volume for the same dose. It's recommended to use 2 mL or 3 mL when reconstituting.
Enter your target dose
Type in the dose you want per injection — in mcg or mg, use the unit toggle to switch. The calculator divides your target dose by the total vial content, then multiplies by the water volume to give your exact draw in milliliters.
What is peptide reconstitution?
Reconstitution is the process of dissolving a lyophilized (freeze-dried) peptide powder into bacteriostatic water so it can be injected. The amount of water you add directly affects the concentration of your solution, which is why accurate dosage calculation matters. Too little water and doses become harder to measure precisely; too much and draw volumes get impractically large.
How to reconstitute BPC-157How to read your syringe
Once the calculator gives you a draw volume in milliliters, you need to locate that measurement on your syringe. Different syringe types use different scales — knowing which one you have prevents dosing errors.
Insulin syringe (U-100)
The most common choice for peptide injections. Each small marking equals 0.01 mL, and the full syringe holds 1 mL (100 units). If the calculator gives you 0.25 mL, draw to the 25-unit line.
½ mL insulin syringe (U-50)
Holds 0.5 mL with 50-unit markings. The wider spacing between graduations makes it easier to hit precise draw volumes under 0.5 mL. Each unit still equals 0.01 mL.
1 mL luer lock syringe
Graduated in 0.01 mL increments across the full 1 mL range. A good option when draw volumes are larger or when you need to use a detachable needle. Read the markings in mL directly — no unit conversion needed.
2 mL luer lock syringe
Used when reconstituting with higher water volumes causes draws above 1 mL. Markings are typically in 0.1 mL increments, so precision is slightly lower than a 1 mL syringe for small doses.
Peptide dosing,made simple.
Calculating a peptide dose by hand means dividing your target dose in micrograms by the total micrograms in the vial, then multiplying by the volume of bacteriostatic water you used to reconstitute. Our peptide dosage calculator does this instantly — just enter your vial size, reconstitution volume, and desired dose to get the exact draw volume in milliliters.
Try the accumulation calculatorPeptide dosage calculator stats
3
free calculators
Dosage, blend, and accumulation calculators — all free, no account required.
100+
peptides covered
Pre-loaded half-life and dosage data for over 100 research peptides.
Instant
draw volume results
Enter your vial size and target dose — get your exact syringe draw in seconds.
More peptide calculation tools
The dosage calculator is just the start. Use the blend calculator to work out ratios when mixing two peptides into a single syringe, or use the accumulation calculator to model how a peptide builds up in your system over a dosing cycle based on its half-life.
Frequently asked questions
What is a peptide dosage calculator?
A peptide dosage calculator is a free tool that converts your vial size, bacteriostatic water volume, and target dose into an exact syringe draw volume. Instead of doing the reconstitution math by hand, you enter three inputs and instantly get the concentration of your solution and how many milliliters or syringeunits to draw. This calculator works for single peptide compounds and multi-peptide blends.
How do I calculate peptide dosage from a vial?
To calculate your peptide dose, divide the total peptide content of your vial in micrograms by the volume of bacteriostatic water you added in milliliters. This gives you your solution concentration in mcg/mL. Then divide your target dose by that concentration to get your draw volume. For example, a 5mg (5,000 mcg) vial reconstituted with 2mL of BAC water gives a concentration of 2,500 mcg/mL. A 250 mcg dose would require drawing 0.1mL. This calculator automates all of those steps instantly.
How much Bacteriostatic water should I add to a peptide vial?
Most people add 2mL to 3mL of bacteriostatic water per vial, but the right amount depends on the dose you want to draw and the syringe size you are using. Adding 1mL to a 5mg vial gives you a concentration of 5,000 mcg/mL, making each dose very small in volume. Adding 2mL gives you 2,500 mcg/mL, which is easier to measure on a standard insulin syringe. A general guideline is to choose a volume that puts your typical dose somewhere between 10 and 30 units on a U-100 syringe. Use the calculator above to test different water volumes and find what works for your dose.
How are peptides different from proteins?
Both are made of amino acids, but peptides are much smaller than proteins. Because of their tiny size, peptides can act like tiny messengers in the body, sending specific signals to your cells to tell them exactly what to do.