Calculators by peptide
Each version is preset to the Biogenesis Labs vial sizes for that compound and includes its own reconstitution chart. The math is the same as the calculator above.
How the peptide calculator works
A peptide calculator converts two numbers from the lab bench — the peptide mass printed on the vial and the volume of diluent added — into a concentration. Every other figure it shows comes from that concentration.
concentration (mg/mL) = peptide mass (mg) ÷ diluent volume (mL)
From there:
- mcg per mL = mg/mL × 1,000
- mcg per unit on a U-100 syringe = mcg per mL ÷ 100 (because 100 units = 1 mL)
- mcg per unit on a U-40 syringe = mcg per mL ÷ 40 (because 40 units = 1 mL)
- mL for a given number of units (U-100) = units ÷ 100
Worked example
A vial labeled 10 mg is reconstituted with 2 mL of bacteriostatic water.
- Concentration: 10 mg ÷ 2 mL = 5 mg/mL (5,000 mcg/mL)
- Per U-100 unit: 5,000 mcg ÷ 100 = 50 mcg per unit
- 10 units on a U-100 syringe = 0.10 mL = 500 mcg
Change only the water to 3 mL and the same vial reads 3.33 mg/mL, or 33.3 mcg per U-100 unit. More diluent always means a lower concentration; the peptide mass in the vial does not change.
Peptide reconstitution chart
Concentration for common vial sizes and diluent volumes. The second figure in each cell is the peptide mass in 10 units on a U-100 syringe (0.10 mL).
| Vial | 1 mL | 2 mL | 3 mL | 5 mL |
|---|---|---|---|---|
| 2 mg | 2.00 mg/mL 200 mcg | 1.00 mg/mL 100 mcg | 0.67 mg/mL 67 mcg | 0.40 mg/mL 40 mcg |
| 5 mg | 5.00 mg/mL 500 mcg | 2.50 mg/mL 250 mcg | 1.67 mg/mL 167 mcg | 1.00 mg/mL 100 mcg |
| 10 mg | 10.00 mg/mL 1,000 mcg | 5.00 mg/mL 500 mcg | 3.33 mg/mL 333 mcg | 2.00 mg/mL 200 mcg |
| 15 mg | 15.00 mg/mL 1,500 mcg | 7.50 mg/mL 750 mcg | 5.00 mg/mL 500 mcg | 3.00 mg/mL 300 mcg |
| 20 mg | 20.00 mg/mL 2,000 mcg | 10.00 mg/mL 1,000 mcg | 6.67 mg/mL 667 mcg | 4.00 mg/mL 400 mcg |
| 30 mg | 30.00 mg/mL 3,000 mcg | 15.00 mg/mL 1,500 mcg | 10.00 mg/mL 1,000 mcg | 6.00 mg/mL 600 mcg |
| 40 mg | 40.00 mg/mL 4,000 mcg | 20.00 mg/mL 2,000 mcg | 13.33 mg/mL 1,333 mcg | 8.00 mg/mL 800 mcg |
Values are rounded to two decimals. Figures describe solution concentration only and are not recommendations.
Reading U-100 and U-40 syringe units
Insulin-style syringes are marked in units, not milliliters, and the scale depends on the syringe type:
- U-100: 100 units = 1 mL, so 1 unit = 0.01 mL. The most common scale.
- U-40: 40 units = 1 mL, so 1 unit = 0.025 mL.
The same number of units holds a different volume on each scale, so always match the calculator's syringe setting to the syringe you are reading.
Bacteriostatic water vs. sterile water
- Bacteriostatic water (BAC water) is sterile water containing 0.9% benzyl alcohol, a preservative that inhibits bacterial growth. It is commonly used when a reconstituted vial will be accessed more than once.
- Sterile water contains no preservative and is generally treated as single-use once opened.
Check the diluent recommended in your own protocol or the compound's documentation. The calculator's math is the same for either diluent.
How to reconstitute a lyophilized peptide vial
- Let the sealed vial reach room temperature.
- Wipe the vial stopper and the diluent stopper with an alcohol swab.
- Draw the chosen volume of diluent.
- Insert the needle at an angle and let the diluent run slowly down the inside wall of the vial, not directly onto the powder.
- Swirl gently until the powder is fully dissolved. Do not shake.
- Label the vial with the peptide, concentration and date of reconstitution.
Storage after reconstitution
Lyophilized (powder) peptides are generally stored cold and dry, away from light. Once reconstituted, peptide solutions are commonly kept refrigerated at 2–8 °C and protected from light. Stability after reconstitution varies by compound, so refer to the product's documentation. Biogenesis Labs publishes independent Certificates of Analysis for its research peptides.
Peptide calculator FAQ
What does a peptide calculator do?
A peptide calculator converts a vial's labeled peptide mass and the volume of diluent added into a concentration, expressed as mg/mL, mcg/mL and mcg per syringe unit. It is concentration math; it does not recommend an amount.
How do you calculate peptide concentration?
Divide the peptide mass in the vial by the volume of diluent added: concentration (mg/mL) = mass (mg) ÷ volume (mL). A 10 mg vial with 2 mL of diluent is 5 mg/mL.
How many units are in 1 mL?
On a U-100 syringe, 100 units equal 1 mL. On a U-40 syringe, 40 units equal 1 mL.
How do you convert mg to mcg?
Multiply by 1,000. 1 mg = 1,000 mcg, so 5 mg/mL is 5,000 mcg/mL.
How do you convert syringe units to mcg?
Find the concentration in mcg/mL, divide by the syringe scale (100 for U-100, 40 for U-40) to get mcg per unit, then multiply by the number of units.
Does adding more water change the amount of peptide in the vial?
No. The peptide mass stays the same; more diluent only spreads it through a larger volume, which lowers the concentration.
How much bacteriostatic water should be added to a peptide vial?
There is no single correct volume. The volume is set by your own protocol; the calculator shows the concentration that results from whatever volume you choose.
What is the difference between bacteriostatic water and sterile water?
Bacteriostatic water contains 0.9% benzyl alcohol as a preservative and is commonly used for vials accessed more than once. Sterile water contains no preservative.
Does this calculator provide dosing guidance?
No. It performs concentration and unit-conversion math only. All Biogenesis Labs products are supplied for laboratory research use only and are not for human consumption.
