Peptide vial calculator
Vial mass, water added and an amount in, concentration, volume, U-100 syringe units and amounts per vial out.
Lyophilized peptides arrive as a dry powder measured in milligrams. Once a liquid is added, every measurement is a volume, and the conversion from mass to volume depends on two numbers: what the vial holds and how much liquid went in. This calculator does that conversion for any peptide and shows the result on a U-100 syringe scale.
Peptide calculator
- Concentration
- 2.50 mg/mL
- 2,500 mcg/mL
- Volume
- 0.100 mL
- Amount
- 250 mcg
- Amounts per vial
- 20
- 20 whole
Results are arithmetic from the three numbers entered. U-100 scale: 100 units = 1 mL. Presets are figures reported in published and community sources, offered as shortcuts, not recommendations. The vial label is the number to trust.
Calculators with presets for a specific peptide
Each page has the vial sizes that peptide is usually sold in, a reconstitution chart and, where enough calculations have been logged, the setups entered most often. Blend pages also split each amount into its components.
- KLOWSyringe units, draw volume and the per-peptide split for an 80 mg KLOW vial.
- RetatrutideConcentration, draw volume and U-100 units for retatrutide vials from 5 to 60 mg.
- MOTS-cConcentration, volume and U-100 units for MOTS-c vials of 5 to 40 mg.
- GHK-CuConcentration, volume and U-100 units for 50, 100 and 200 mg GHK-Cu vials.
- Wolverine blendU-100 units and the per-peptide split for 10, 20 and 40 mg BPC-157 + TB-500 blend vials.
- CJC-1295 + IpamorelinU-100 units and the per-peptide split for a 5 mg / 5 mg CJC-1295 + ipamorelin vial.
- TesamorelinConcentration, volume and U-100 units for tesamorelin vials of 2 to 20 mg.
- SS-31Concentration, volume and U-100 units for 5, 10 and 20 mg SS-31 vials.
- BPC-157Concentration, draw volume and U-100 units for 5 and 10 mg BPC-157 vials.
- TB-500Concentration, draw volume and U-100 units for TB-500 vials from 2 to 30 mg.
- Glow blendU-100 units and the per-peptide split for 70 mg and 30 mg Glow blend vials.
- KPVConcentration, draw volume and U-100 units for 5 and 10 mg KPV vials.
- Melanotan IIConcentration, draw volume and U-100 units for 5 and 10 mg Melanotan II vials.
- PT-141Concentration, draw volume and U-100 units for 5 and 10 mg PT-141 vials.
- CagrilintideConcentration, draw volume and U-100 units for 5 and 10 mg cagrilintide vials.
- IGF-1 LR3Concentration, draw volume and U-100 units for 100 mcg and 1 mg IGF-1 LR3 vials.
- DSIPConcentration, draw volume and U-100 units for 2, 5 and 10 mg DSIP vials.
- SelankConcentration, draw volume and U-100 units for 5, 10 and 30 mg Selank vials.
- SemaxConcentration, draw volume and U-100 units for Semax vials from 5 to 30 mg.
- GlutathioneConcentration in mg/mL, draw volume in mL and the U-100 equivalent for 600 and 1,500 mg glutathione vials.
How the calculation works
There are three steps, and each one is a single division or multiplication:
- Concentration = vial mass (mg) / liquid added (mL). A 5 mg vial with 2 mL is 2.5 mg/mL.
- Volume = amount (mg) / concentration. 0.25 mg at 2.5 mg/mL is 0.1 mL.
- Syringe units = volume (mL) x 100 on a U-100 syringe. 0.1 mL is 10 units.
Amounts per vial is the vial mass divided by the amount: 5 mg / 0.25 mg = 20. Adding more water lowers the concentration and makes each amount a larger volume, which is easier to read on the scale but needs more room in the syringe. The syringe units page covers the scale itself in more detail.
Quick reference
U-100 readings for common vial sizes and water volumes. The amounts are examples, not suggestions.
5 mg vial
| Water | Concentration | 100 mcg | 250 mcg | 500 mcg |
|---|---|---|---|---|
| 1 mL | 5,000 mcg/mL | 2 u0.02 mL | 5 u0.05 mL | 10 u0.1 mL |
| 2 mL | 2,500 mcg/mL | 4 u0.04 mL | 10 u0.1 mL | 20 u0.2 mL |
| 2.5 mL | 2,000 mcg/mL | 5 u0.05 mL | 12.5 u0.125 mL | 25 u0.25 mL |
| 3 mL | 1,667 mcg/mL | 6 u0.06 mL | 15 u0.15 mL | 30 u0.3 mL |
10 mg vial
| Water | Concentration | 250 mcg | 500 mcg | 1 mg |
|---|---|---|---|---|
| 1 mL | 10 mg/mL | 2.5 u0.025 mL | 5 u0.05 mL | 10 u0.1 mL |
| 2 mL | 5,000 mcg/mL | 5 u0.05 mL | 10 u0.1 mL | 20 u0.2 mL |
| 3 mL | 3,333 mcg/mL | 7.5 u0.075 mL | 15 u0.15 mL | 30 u0.3 mL |
| 5 mL | 2,000 mcg/mL | 12.5 u0.125 mL | 25 u0.25 mL | 50 u0.5 mL |
Calculator questions
How is peptide concentration calculated after reconstitution?
Divide the mass in the vial by the volume of liquid added. A 5 mg vial with 2 mL of bacteriostatic water is 2.5 mg/mL, which is 2,500 mcg/mL. The water does not change the total mass in the vial, only how concentrated it is.
How many units is 250 mcg from a 5 mg vial with 2 mL of water?
At 2,500 mcg/mL, 250 mcg occupies 0.1 mL, which reads 10 units on a U-100 syringe. The vial holds 20 amounts of 250 mcg.
What is a unit on an insulin syringe?
On a U-100 syringe, 100 units equal 1 mL, so 1 unit is 0.01 mL. A unit measures volume only. How much peptide a unit holds depends entirely on the concentration in the vial.
Does syringe size change the number of units?
No. A 0.3 mL, 0.5 mL and 1 mL U-100 syringe all use the same scale; a smaller barrel just holds fewer units (30, 50 or 100). The calculator flags a result that is larger than the barrel selected.
How many amounts are in one vial?
Divide the vial mass by the amount. A 10 mg vial holds 40 amounts of 250 mcg regardless of how much water was added. The calculator shows the exact figure and the number of whole amounts.
Is mcg or mg used in the calculation?
Either. 1 mg is 1,000 mcg. The calculator converts the amount to mg internally, so entering 250 mcg or 0.25 mg gives the same result.
Setup data on the peptide pages covers 4,225 logged calculations. About the data.