18 mg vial, 2 mL water, 9 mg/mL.
18 milligrams divided by 2 millilitres of bacteriostatic water gives 9 mg per mL. Every unit reading on this page follows from that one number.
The direct answer
A 18 mg vial reconstituted with 2 mL of bacteriostatic water is 9 mg/mL. One unit on a U-100 syringe is 0.01 mL, so one unit of this solution contains 0.09 mg, and 10 units contains 0.9 mg.
18 mg ÷ 2 mL = 9 mg/mL
An 18 mg vial is an awkward number, which is exactly why the arithmetic gets searched. This page exists because that exact combination is searched for: "an 18mg peptide bottle with 2 ml of bacteriostatic water will be how many".
This page is arithmetic only. It converts numbers you already have from the vial in front of you and the prescription you were given. It does not tell you how much water to add, how much to take, or how often. Those are medical decisions for a licensed clinician who knows your history.
Amount to units at 9 mg/mL
Every row is computed for this concentration only. Rows that would exceed a 1 mL U-100 barrel are left out, because they cannot be drawn in one go.
| Amount | In mcg | Volume | U-100 units |
|---|---|---|---|
| 0.1 mg | 100 mcg | 0.011 mL | 1.1 u |
| 0.25 mg | 250 mcg | 0.028 mL | 2.8 u |
| 0.5 mg | 500 mcg | 0.056 mL | 5.6 u |
| 0.75 mg | 750 mcg | 0.083 mL | 8.3 u |
| 1 mg | 1000 mcg | 0.111 mL | 11.1 u |
| 1.5 mg | 1500 mcg | 0.167 mL | 16.7 u |
| 2 mg | 2000 mcg | 0.222 mL | 22.2 u |
| 2.5 mg | 2500 mcg | 0.278 mL | 27.8 u |
| 3 mg | 3000 mcg | 0.333 mL | 33.3 u |
| 4 mg | 4000 mcg | 0.444 mL | 44.4 u |
| 5 mg | 5000 mcg | 0.556 mL | 55.6 u |
1 mg on the barrel
18 mg in 2 mL = 9 mg/mL → 1 mg dose = 0.111 mL = 11.1 units
Questions people actually type
What concentration is a 18 mg vial in 2 mL?
18 mg divided by 2 mL is 9 mg/mL. On a U-100 syringe one unit is 0.01 mL, so a single unit of this solution holds 0.09 mg.
How many units is 1 mg from a 18 mg vial in 2 mL?
1 mg divided by 9 mg/mL is 0.111 mL, which reads 11.1 units on a U-100 syringe.
Does the 18 mg vial still hold 18 mg after adding water?
Yes. The mass is fixed by the label. Adding 2 mL of bacteriostatic water changes only the concentration, to 9 mg/mL, and therefore only the unit reading for a given amount.
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