Pen and vial guide / Zepbound
Zepbound Pens and Vials: Volumes and Units
Zepbound comes in single-dose 0.5 mL pens and vials, plus multi-dose vials and KwikPens that give 0.6 mL per dose. The form you have changes how many units a dose is.
Last updated
- Medicine
- Tirzepatide
- Forms on the label
- 4
Every form on the label
Each form, its strength, and how much liquid one dose is.
| Form | Strength on the label | mg per mL | Doses | Liquid per dose |
|---|---|---|---|---|
| single-dose pen | 2.5 mg / 0.5 mL | 5.00 | 1 dose | 0.50 mL |
| single-dose pen | 5 mg / 0.5 mL | 10.00 | 1 dose | 0.50 mL |
| single-dose pen | 7.5 mg / 0.5 mL | 15.00 | 1 dose | 0.50 mL |
| single-dose pen | 10 mg / 0.5 mL | 20.00 | 1 dose | 0.50 mL |
| single-dose pen | 12.5 mg / 0.5 mL | 25.00 | 1 dose | 0.50 mL |
| single-dose pen | 15 mg / 0.5 mL | 30.00 | 1 dose | 0.50 mL |
| single-dose vial | 2.5 mg / 0.5 mL | 5.00 | 1 dose | 0.50 mL |
| single-dose vial | 5 mg / 0.5 mL | 10.00 | 1 dose | 0.50 mL |
| single-dose vial | 7.5 mg / 0.5 mL | 15.00 | 1 dose | 0.50 mL |
| single-dose vial | 10 mg / 0.5 mL | 20.00 | 1 dose | 0.50 mL |
| single-dose vial | 12.5 mg / 0.5 mL | 25.00 | 1 dose | 0.50 mL |
| single-dose vial | 15 mg / 0.5 mL | 30.00 | 1 dose | 0.50 mL |
| multi-dose vial | 10 mg / 2.4 mL | 4.17 | 4 × 0.6 mL | 0.60 mL |
| multi-dose vial | 20 mg / 2.4 mL | 8.33 | 4 × 0.6 mL | 0.60 mL |
| multi-dose vial | 30 mg / 2.4 mL | 12.50 | 4 × 0.6 mL | 0.60 mL |
| multi-dose vial | 40 mg / 2.4 mL | 16.67 | 4 × 0.6 mL | 0.60 mL |
| multi-dose vial | 50 mg / 2.4 mL | 20.83 | 4 × 0.6 mL | 0.60 mL |
| multi-dose vial | 60 mg / 2.4 mL | 25.00 | 4 × 0.6 mL | 0.60 mL |
| KwikPen | 10 mg / 2.4 mL | 4.17 | 4 × 0.6 mL | 0.60 mL |
| KwikPen | 20 mg / 2.4 mL | 8.33 | 4 × 0.6 mL | 0.60 mL |
| KwikPen | 30 mg / 2.4 mL | 12.50 | 4 × 0.6 mL | 0.60 mL |
| KwikPen | 40 mg / 2.4 mL | 16.67 | 4 × 0.6 mL | 0.60 mL |
| KwikPen | 50 mg / 2.4 mL | 20.83 | 4 × 0.6 mL | 0.60 mL |
| KwikPen | 60 mg / 2.4 mL | 25.00 | 4 × 0.6 mL | 0.60 mL |
Single-dose vs multi-dose
Single-dose pens and vials come in 2.5, 5, 7.5, 10, 12.5 and 15 mg per 0.5 mL. Multi-dose vials and KwikPens (for one person only) hold 2.4 mL and give four 0.6 mL doses. The multi-dose forms contain benzyl alcohol, glycerin and phenol. According to the cited label, the single-dose pen and vial don’t contain those multi-dose preservatives.
The KwikPen only gives set doses. You turn the knob until it stops. After four doses, the pen won’t let you set a full dose. The KwikPen instructions for use say, “Do not transfer ZEPBOUND from your Pen into a syringe.” So this page treats the pen as its own device and only uses syringe math for vials.
The instructions for the single-dose vial say to use a syringe and needle bought separately, such as a 1 mL syringe and needle your healthcare provider recommends. They don’t say what needle thickness (gauge) or length to use.
Drawing from a single-dose vial, as the instructions describe
If you have a single-dose vial, see the Zepbound vial doses and syringe instructions.
The steps for a single-dose vial are: pull 0.5 mL of air into the syringe, push that air into the vial, turn the vial upside down, and pull the plunger past the 0.5 mL line. Tap the syringe so bubbles rise to the top, then push the plunger tip back to the 0.5 mL line. Keep the needle in your skin for at least 5 seconds. The instructions say to throw away every opened single-dose vial after use, even if there’s medicine left. They don’t say to use everything in the vial.
The multi-dose vial instructions use the same steps (air in, then turn the vial upside down) with the 0.6 mL line, and a new syringe and needle each time. The 0.5 mL and 0.6 mL lines come from the label for each form. They aren’t a recommendation to pick one.
Drawing from a vial
Five steps to your line.
01 / 05
Put air in
Lilly's Zepbound vial instructions say to start by putting air into the vial.
Line: 50 units = 0.50 mL on a U-100 syringe
Dose increases, injection sites, missed doses and storage
The Zepbound label starts at 2.5 mg a week for 4 weeks, then 5 mg. Each increase is 2.5 mg, after at least 4 weeks on the current dose. The 2.5 mg dose is only for starting. It isn’t a dose to stay on. The dose to stay on (the maintenance dose) is 5, 10 or 15 mg for weight, and 10 or 15 mg for obstructive sleep apnea (OSA). The most is 15 mg a week. This is what the label says, not a dose recommendation.
Inject into the belly (abdomen) or thigh. The back of the upper arm is only for when someone else gives the injection. Switch spots with each dose, and within the area you choose. A missed dose can be taken within 4 days (96 hours). After that, skip it. Doses must be at least 72 hours apart.
Keep single-dose pens and vials in the fridge at 2–8 °C (36–46 °F). They can be kept at 30 °C (86 °F) or below for a total of 21 days. Throw away multi-dose vials and KwikPens after 30 days at room temperature, 30 days after first use, or four doses, whichever comes first.
Common questions
How many U-100 units is a Zepbound single-dose vial?
The 0.5 mL dose on the label is 50 units on a U-100 syringe.
How many units is a Zepbound multi-dose vial dose?
The 0.6 mL dose on the label is 60 units on a U-100 syringe.
Can I transfer a KwikPen into a syringe?
No. The KwikPen instructions for use say not to transfer Zepbound from the pen into a syringe.
More on the math
Pens don’t use syringe units. If you draw from a vial, these explain the math.
Sources
The medical and device facts on this page come from these sources. Each entry shows the date we accessed it.
- 01 Zepbound (tirzepatide) US Prescribing Information · Eli Lilly, 08/2026. Accessed 2026-09-28.
- 02 Zepbound single-dose vial Instructions for Use · Eli Lilly, 04/2026. Accessed 2026-09-28.
- 03 Zepbound full US labeling · Eli Lilly, 08/2026. Accessed 2026-10-01.
- 04 Technical Data Sheet – Insulin Syringes · embecta, Rev B, 12/2025. Accessed 2026-09-28.
Medically reviewed by Ashley Alexis, NDLast reviewed How we review