Oxytocin 5 mg vial
How much bacteriostatic water to add to a 5 mg vial of Oxytocin, the syringe units for each common dose, and how many doses the vial holds.
- Water
- 5 mL
- Strength
- 1 mg/mL
- Common dose
- 24 IU
- Draw
- 4 units0.040 mL
- Doses per vial
- 123
The short answer
Mixed with 5 mL of bacteriostatic water, a 5 mg vial of Oxytocin holds 1 mg/mL. A 24 IU dose is then 4 units (0.040 mL) on a U-100 insulin syringe, and the vial holds about 123 doses of that size.
How much water
The water only sets the strength; the dose and the number of doses in the vial stay the same. Draws are on a U-100 insulin syringe, where 1 unit is 0.01 mL.
| Water added | Strength | Per syringe unit | Draw for 24 IU |
|---|---|---|---|
| 2.5 mL | 2 mg/mL | 20 mcg | 2 units (0.020 mL) |
| 3 mL | 1.667 mg/mL | 16.7 mcg | 2.4 units (0.024 mL) |
| 5 mL | 1 mg/mL | 10 mcg | 4 units (0.040 mL) |
Dose chart
Syringe units for each common dose at each water volume. Select a cell to open it in the calculator.
| Dose | Water added | ||
|---|---|---|---|
| 2.5 mL | 3 mL | 5 mL | |
| 18 IU | |||
| 20 IU | |||
| 24 IU | |||
| 25 IU | |||
| 30 IU | |||
| 40 IU | |||
Draws over 100 units show in mL. Faded values are under 2 units, which is hard to measure. Check that your vial holds the larger volumes.
Where the doses come from
- Trial Intranasal: a single 18–40 IU dose, most studies 20–24 IU, taken 45–60 minutes before the task.
- Label Obstetric use only, given by clinicians by IV infusion or as 10 units IM after delivery.
Doses are what labels, trials or community reports reference, not recommendations. Oxytocin’s page has the cycle, side effects, cautions and sources.
Mixing and storage
- PrepareLet a refrigerated vial come to room temperature, and wipe both stoppers with an alcohol swab.
- Add 5 mLDraw 5 mL of bacteriostatic water and let it run slowly down the inside wall of the vial.
- Swirl, don’t shakeSwirl gently until the powder dissolves and the liquid is clear.
- Label itWrite the date and the strength, 1 mg/mL, on the vial.
Storage: Mixed: 2–8 °C.
The reconstitution guide covers each step, and the units page explains syringe markings.
Questions
How much water do I add to a 5 mg vial of oxytocin?
There’s no single right amount: the water only sets the strength. With 5 mL of bacteriostatic water, a 5 mg vial holds 1 mg/mL. With 2.5 mL it’s 2 mg/mL; with 3 mL it’s 1.667 mg/mL. Less liquid makes each dose a smaller draw; more makes small doses easier to measure.
How many units is 24 IU of oxytocin?
With 5 mL in a 5 mg vial, 24 IU is 4 units (0.040 mL) on a U-100 insulin syringe. With 2.5 mL, 2 units (0.020 mL); with 3 mL, 2.4 units (0.024 mL).
How many doses are in a 5 mg vial of oxytocin?
About 123 doses of 24 IU, or 99 of 30 IU or 74 of 40 IU.
How long does a mixed vial of oxytocin keep?
Mixed: 2–8 °C.
Other vial sizes
Sources
- Pitocin (oxytocin) label (DailyMed)
- MacDonald et al., safety of intranasal oxytocin (2011) PMID 21429671
The math on this page uses the doses and storage on Oxytocin’s page.