Peptide Calculator:
Instant Reconstitution & Dosage Tool
Calculate the exact syringe units to draw for any peptide — enter your vial size, BAC water volume, and desired dose. Results in seconds.
1 Select Syringe Volume
2 Peptide Vial Quantity
3 Bacteriostatic Water Added
4 Desired Dose per Injection
+ IU Conversion Optional
For GH-related peptides (HGH, Sermorelin). Enter the IU-per-mg factor for your compound.
How to Use This Peptide Calculator
This peptide reconstitution calculator takes four inputs and instantly returns your exact syringe draw. Here is what each step means:
Choose 0.3 ml (30 units), 0.5 ml (50 units), or 1.0 ml (100 units). All three are U-100 insulin syringes — they hold different volumes but all mark 100 units per ml at their respective scale.
The total milligrams (mg) of lyophilized peptide in your vial. Common sizes are 5 mg and 10 mg. For peptide blends, enter each compound separately.
The volume (ml) of BAC water you added — or plan to add — to the vial. This directly determines the concentration of your reconstituted solution.
Enter how many micrograms (mcg), milligrams (mg), or IU you want per injection. For weight-based protocols, toggle the mcg/kg option and enter your body weight instead.
What Is a Peptide Calculator?
A peptide calculator — also called a peptide reconstitution calculator or peptide dosage calculator — is a tool that converts vial peptide content, solvent volume, and desired dose into a precise syringe draw volume. It eliminates manual arithmetic and reduces measurement errors during laboratory reconstitution preparation.
The underlying reconstitution formula is:
- Concentration (mcg/ml) = Peptide in vial (mg) × 1,000 ÷ BAC water added (ml)
- Draw volume (ml) = Desired dose (mcg) ÷ Concentration (mcg/ml)
- Syringe units = Draw volume (ml) × Units per ml of chosen syringe
Peptide Reconstitution: Step-by-Step Guide
Wipe the surface with isopropyl alcohol. Wash hands thoroughly. Use nitrile gloves where required by your research protocol.
Clean the rubber stopper with an alcohol swab and allow it to dry completely before inserting a needle.
Use this peptide calculator first. Choose a BAC water amount that results in a round syringe unit number per dose — for example, exactly 10 or 20 units — so the draw is easy to measure and repeat consistently.
Draw the chosen BAC water volume into a sterile syringe. Insert the needle at an angle and let the water run slowly down the inside glass wall — do not squirt it directly onto the lyophilized powder, as this can degrade the peptide.
Rotate the vial between your fingers until the powder fully dissolves. The solution should be clear and colorless. GHK-Cu is a normal exception — it produces a blue-tinted solution.
Label with peptide name, concentration, reconstitution date, and initials. Store at 2–8°C away from light. Most reconstituted peptides remain stable for 4–6 weeks when properly refrigerated.
Unit Conversions for Peptide Dosing
| Unit | Equivalent | Notes |
|---|---|---|
| 1 mg | 1,000 mcg | Vials labeled in mg; doses often in mcg |
| 1 ml | 1 cc | Milliliter and cubic centimeter are identical |
| 1 ml on U-100 syringe | 100 units | Standard insulin syringe |
| 1 ml on U-50 syringe | 50 units | 0.5 ml capacity syringe |
| 1 ml on U-30 syringe | 30 units | 0.3 ml capacity syringe |
| 1 IU of HGH | ≈ 0.333 mg | Factor: 3 IU per mg (verify per compound) |
Bacteriostatic Water vs. Sterile Water
Bacteriostatic water (BAC water) is sterile water containing 0.9% benzyl alcohol, which inhibits bacterial growth. It allows a vial to be safely re-entered multiple times over several weeks and is the standard solvent for peptide reconstitution in research settings.
Sterile water for injection contains no preservative and is appropriate for single-use reconstitution only. For most peptide research protocols involving daily or weekly injections from the same vial, bacteriostatic water is the correct choice.
Weight-Based Peptide Dosing (mcg/kg)
Many research protocols express peptide dosages relative to body weight — for example, 1 mcg/kg or 2 mcg/kg per injection. Toggle the weight-based dosing module above, enter body weight in kilograms or pounds and the mcg/kg protocol, and your total dose and syringe draw are calculated automatically.
Weight-based dosing is particularly common in protocols involving BPC-157, TB-500, Sermorelin, Ipamorelin, and CJC-1295.
How Many Doses Per Vial?
This calculator displays doses per vial automatically. Quick reference:
- 10 mg vial at 250 mcg per dose → 40 doses
- 5 mg vial at 500 mcg per dose → 10 doses
- 10 mg vial at 100 mcg per dose → 100 doses
- 15 mg vial at 300 mcg per dose → 50 doses
Common Peptides and Typical Research Dose Ranges
- BPC-157 — 200–500 mcg per injection, subcutaneous or intramuscular. Typically supplied in 5 mg vials.
- TB-500 (Thymosin Beta-4) — 2–5 mg per week, split across two injections. Supplied in 5–10 mg vials.
- Sermorelin — 200–500 mcg subcutaneous before sleep. Supplied in 3–15 mg vials.
- Ipamorelin — 200–300 mcg per injection, 2–3 times daily.
- CJC-1295 (without DAC) — 100–200 mcg per injection, often combined with Ipamorelin.
- HGH — commonly expressed in IU. Use the IU conversion module with a factor of 3 IU/mg.
- Tirzepatide / Retatrutide — large vials (e.g. 50 mg). Use the custom input and convert dose from mg to mcg.
Frequently Asked Questions
A peptide calculator helps researchers determine the exact volume to draw into a syringe for a specific dose after reconstituting a lyophilized peptide vial with bacteriostatic water. It removes the need for manual calculation and minimizes measurement errors during research preparation.
Use the three-step formula: (1) Concentration (mcg/ml) = vial mg × 1,000 ÷ BAC water ml. (2) Draw volume (ml) = desired dose mcg ÷ concentration. (3) Syringe units = draw volume × units per ml. For example: a 5 mg vial with 2 ml BAC water = 2,500 mcg/ml. A 250 mcg dose needs 0.1 ml = 10 units on a U-100 syringe.
There is no single correct amount — it depends on your desired dose and preferred draw volume. A common strategy is to choose a BAC water volume that results in a round number of syringe units per dose (e.g. exactly 10 or 20 units), making measurement easy to repeat consistently. Use the calculator above to find your ideal volume.
A U-100 syringe holds 1 ml divided into 100 units, so each unit = 0.01 ml. Multiply your draw volume in ml by 100 to get units. Examples: 0.05 ml = 5 units, 0.2 ml = 20 units. For a 0.5 ml (50u) syringe multiply by 50; for a 0.3 ml (30u) syringe multiply by 30. This calculator does this automatically for all three syringe sizes.
1 mg (milligram) equals 1,000 mcg (micrograms). Peptide doses are usually expressed in micrograms because the amounts are small, while vial quantities are labeled in milligrams. This calculator automatically converts between both units.
Most reconstituted peptides remain stable at 2–8°C for 4–6 weeks when stored away from light. Lyophilized (unreconstituted) peptides typically last 1–2 years when stored frozen. Stability varies by compound.
Yes. This peptide reconstitution calculator is completely free with no registration, no account, and no limits on usage.