5 mg vial: units to mg
5 mg in 2 mL is 2.5 mg/mL, so 20 units is 0.5 mg and 10 units is 0.25 mg.
| Water | 10 u | 20 u | 30 u | 50 u |
|---|---|---|---|---|
| 1 mL | 0.5 | 1 | 1.5 | 2.5 |
| 2 mL | 0.25 | 0.5 | 0.75 | 1.25 |
| 3 mL | 0.167 | 0.333 | 0.5 | 0.833 |
Peptide Calculator: Reconstitution & BAC Water
Enter the vial size, the bacteriostatic (BAC) water added and your prescribed dose to get insulin-syringe units. Example: 10 mg in 2 mL is 5 mg/mL, so 20 units on a U-100 syringe holds 1 mg.
How do you calculate peptide reconstitution?
Divide the peptide in the vial (mg) by the bacteriostatic water added (mL) to get mg/mL. Divide the prescribed dose (mg) by that and multiply by 100 for units on a U-100 insulin syringe: 5 mg in 2 mL is 2.5 mg/mL, so 500 mcg is 0.2 mL, or 20 units.
units = dose mg ÷ (vial mg ÷ water mL) × 100
Units to mg for common peptide vials
What a U-100 syringe reading contains, by vial size and bacteriostatic water: mg = units ÷ 100 × (vial mg ÷ water mL).
10 mg vial: units to mg
10 mg in 2 mL is 5 mg/mL, so 20 units is 1 mg and 10 units is 0.5 mg.
| Water | 10 u | 20 u | 30 u | 50 u |
|---|---|---|---|---|
| 1 mL | 1 | 2 | 3 | 5 |
| 2 mL | 0.5 | 1 | 1.5 | 2.5 |
| 3 mL | 0.333 | 0.667 | 1 | 1.67 |
20 mg vial: units to mg
20 mg in 2 mL is 10 mg/mL, so 20 units is 2 mg and 10 units is 1 mg.
| Water | 10 u | 20 u | 30 u | 50 u |
|---|---|---|---|---|
| 1 mL | 2 | 4 | 6 | 10 |
| 2 mL | 1 | 2 | 3 | 5 |
| 3 mL | 0.667 | 1.33 | 2 | 3.33 |
30 mg vial: units to mg
30 mg in 2 mL is 15 mg/mL, so 20 units is 3 mg and 10 units is 1.5 mg.
| Water | 10 u | 20 u | 30 u | 50 u |
|---|---|---|---|---|
| 1 mL | 3 | 6 | 9 | 15 |
| 2 mL | 1.5 | 3 | 4.5 | 7.5 |
| 3 mL | 1 | 2 | 3 | 5 |
mg per reading; 1 mg = 1,000 mcg. Assumes the whole vial is dissolved in the stated water and a U-100 syringe (100 units = 1 mL). Reads a syringe marking back into mg; it is not a dose for any peptide. Want this tool on your site? Embed this calculator.
How much bacteriostatic water should I add?
The volume your prescriber or pharmacist specifies. More water means more units per dose (easier to read), never more doses. Your vial at each volume:
| Water | Units | mL | mg/mL |
|---|---|---|---|
| 1 mL | 5 | 0.05 | 5 |
| 1.5 mL | 7.5 | 0.075 | 3.33 |
| 2 mL | 10 | 0.1 | 2.5 |
| 2.5 mL | 12.5 | 0.125 | 2 |
| 3 mL | 15 | 0.15 | 1.67 |
Peptide reconstitution chart
Top: mg/mL after mixing. Below: U-100 units per 100 mcg.
| Vial | 1 mL | 1.5 mL | 2 mL | 2.5 mL | 3 mL |
|---|---|---|---|---|---|
| 2 mg | 25 | 1.337.5 | 110 | 0.812.5 | 0.66715 |
| 5 mg | 52 | 3.333 | 2.54 | 25 | 1.676 |
| 10 mg | 101 | 6.671.5 | 52 | 42.5 | 3.333 |
| 15 mg | 150.667 | 101 | 7.51.33 | 61.67 | 52 |
| 20 mg | 200.5 | 13.30.75 | 101 | 81.25 | 6.671.5 |
| 30 mg | 300.333 | 200.5 | 150.667 | 120.833 | 101 |
Common peptide vial sizes and FDA status
| Peptide | Vial sizes | FDA status |
|---|---|---|
| BPC-157 | 5 mg, 10 mg | Not FDA-approved; no legal compounding pathway. |
| Tirzepatide | 10 mg, 20 mg, 30 mg, 60 mg | FDA-approved only as Mounjaro and Zepbound; compounded and research versions are not. |
| Semaglutide | 2 mg, 5 mg, 10 mg | FDA-approved only as Ozempic, Wegovy and Rybelsus; compounded and research versions are not. |
| Retatrutide | 5 mg, 10 mg, 20 mg, 30 mg | Investigational (in Phase 3 trials); not FDA-approved. |
| TB-500 | 2 mg, 5 mg, 10 mg | Not FDA-approved; research chemical; banned by WADA. |
| BPC-157 + TB-500 | 5 + 5 mg, 10 + 10 mg | Neither is FDA-approved; research chemicals, not for human use. |
| GHK-Cu | 50 mg, 100 mg | Not FDA-approved as an injectable. |
| MOTS-c | 5 mg, 10 mg | Not FDA-approved. |
| Ipamorelin | 2 mg, 5 mg, 10 mg | Not FDA-approved. |
| CJC-1295 | 5 mg, 10 mg | Not FDA-approved. |
| CJC-1295 + Ipamorelin | 2 + 2 mg, 5 + 5 mg | Neither is FDA-approved; research chemicals, not for human use. |
| Sermorelin | 2 mg, 5 mg, 10 mg | No FDA-approved product on the market; compounded versions are not FDA-approved. |
| Tesamorelin | 2 mg, 5 mg, 10 mg | FDA-approved only as Egrifta; other versions are not. |
| NAD+ | 100 mg, 500 mg, 1000 mg | Not a peptide; not an FDA-approved injectable. |
How to reconstitute a peptide vial
- Follow your pharmacist's instructions first.
- Swab both stoppers with alcohol; use a new sterile syringe.
- Add the water slowly down the vial wall.
- Swirl gently; don't shake. Don't use it if cloudy.
- Label the mix date and store as directed.
Peptide calculator FAQ
How many units is 1 mL on an insulin syringe?
100 units on a U-100 syringe, 50 on a U-50 and 40 on a U-40. So 0.2 mL is 20 units on a U-100.
What is the difference between mcg and mg?
1 mg is 1,000 mcg, so 250 mcg is 0.25 mg. Set mcg or mg next to the dose to avoid a 1,000-fold error.
How much bacteriostatic water do I add to a 10 mg vial?
The volume your prescriber or pharmacist specifies; the water sets the concentration, not the amount of peptide. 10 mg in 1 mL is 10 mg/mL (10 units = 1 mg), in 2 mL 5 mg/mL (10 units = 0.5 mg), and in 3 mL 3.33 mg/mL (10 units = 0.333 mg) on a U-100 syringe.
How many mg is 20 units of retatrutide?
It depends on how the vial was mixed. On a U-100 syringe 20 units is 0.2 mL: 1 mg from a 10 mg vial with 2 mL of bacteriostatic water, 0.5 mg from a 5 mg vial with 2 mL, and 2 mg from a 20 mg vial with 2 mL. Retatrutide is investigational and not FDA-approved.
How do you convert mcg to units?
Divide mcg by 1,000 for mg, divide by the vial's mg/mL for mL, then multiply by 100 for U-100 units. A 5 mg vial mixed with 2 mL is 2.5 mg/mL, so 10 units holds 0.25 mg (250 mcg) and 20 units holds 0.5 mg.
How do you read units on a U-100 syringe?
Each unit is 0.01 mL, and the numbers mark every 10 units. On 0.3 mL and 0.5 mL syringes each small line is usually 1 unit; on a 1 mL syringe it is usually 2 units. Check the scale printed on your barrel.
How many doses are in a peptide vial?
Divide the vial amount by the dose in the same unit: a 5 mg vial holds ten 0.5 mg doses. The water volume does not change the count.
How do you calculate a blend vial?
Enter both amounts and choose which peptide your prescribed dose refers to. The calculator sizes the draw for that peptide and shows how much of the other comes with it.
Is bacteriostatic water the same as sterile water?
No. Bacteriostatic water contains 0.9% benzyl alcohol so a vial can be entered more than once; sterile water has no preservative and is single-use.
How long does bacteriostatic water last once opened?
CDC guidance, citing USP chapter 797, says to date an opened multi-dose vial and discard it within 28 days unless the manufacturer states another date. Follow your pharmacist on how long a mixed vial keeps.
Are peptides FDA-approved?
A few are, including insulin, semaglutide and tirzepatide. Most peptides sold online are not, and research-use-only products are not for human use.
Does this peptide dosage calculator tell me what dose to take?
No. It converts the dose your prescriber wrote into units and mL; it never suggests one.
Liquid vial already labelled in mg/mL? Use the mg to units calculator, tirzepatide dose calculator or semaglutide dose calculator. Background: what is BPC-157? · TB-500's legal status · all calculators