The Zepbound injection sites approved on the FDA label are the stomach area (abdomen), the front of the thigh, and the back of the upper arm, with the upper arm injected by another person. The label says to rotate injection sites with each dose. The same three areas apply to Mounjaro, which is the same medicine, tirzepatide. Below is what the label and Lilly's Instructions for Use say for each device, what skin to avoid, and how common injection site reactions were in the trials.
By Alexandru Vieru | Independently researched | Every instruction on this page is from the Zepbound and Mounjaro prescribing information and Lilly's FDA-approved Instructions for Use, read on DailyMed on 21 October 2026. This is general information, not medical advice: your prescriber or pharmacist should show you how to inject before your first dose.
Where can you inject Zepbound?
The Zepbound prescribing information (revised August 2026) gives one sentence on placement: "Inject ZEPBOUND subcutaneously in the abdomen, thigh, or another person should inject in the back of the upper arm. Rotate injection sites with each dose."
"Subcutaneously" means into the fatty layer just under the skin. The Medication Guide adds two limits: do not inject Zepbound into a muscle or into a vein. That gives three Zepbound injection sites:
- Stomach area (abdomen). You can inject here yourself.
- Thigh. You can inject here yourself.
- Back of the upper arm. The single-dose pen and KwikPen instructions say another person should give you the injection here. The reason is practical: it is hard to reach and see the back of your own arm.
The Mounjaro label (revised August 2026) uses the same wording, so "where to inject tirzepatide" has the same answer for both brands.
What is the best place to inject Zepbound?
The label does not rank the Zepbound injection sites or name one best site. In its pharmacology section it says: "Similar exposure was achieved with subcutaneous administration of tirzepatide in the abdomen, thigh, or upper arm." In plain terms, the amount of medicine that reached the blood was similar from all three areas, so choosing the stomach over the thigh does not make a dose stronger or weaker.
The pen instructions say "Your healthcare provider can help you choose the injection site that is best for you." In practice that choice comes down to comfort, how easily you can see and reach the spot, and whether someone can help you with the arm.
How should Zepbound injection sites be rotated?
Every set of Lilly instructions tells you to change (rotate) the injection site each week. The single-dose pen and KwikPen instructions add: "You may use the same area of your body but be sure to choose a different injection site in that area." So you can keep using your abdomen, for example, as long as each weekly shot goes into a different spot within it.
The vial instructions explain why. Rotating within the area you choose for each dose is meant "to reduce your risk of getting lipodystrophy (pits in skin or thickened skin) and localized cutaneous amyloidosis (skin with lumps) at the injection sites."
A simple way to rotate Zepbound injection sites is to move around the body in a fixed order, such as left abdomen, right abdomen, left thigh, right thigh, and to keep a note of where the last dose went. The label does not require any particular pattern, only a different site each time.
How far from the belly button should you inject?
The KwikPen instructions are the only Zepbound instructions that give a distance: inject "in your thigh or stomach (abdomen) at least 2 inches from the belly button." The Mounjaro KwikPen instructions say the same. The single-dose pen and vial instructions name the abdomen without a distance. Keeping 2 inches away from the navel is a reasonable habit with any device, and your pharmacist can confirm it for yours.
Do the pen, KwikPen and vial use the same Zepbound injection sites?
Yes: all four Zepbound devices use the same three areas. What differs is how you hold the device and who may use the upper arm. This table summarizes the Instructions for Use (single-dose pen and single-dose vial revised April 2026; multi-dose vial and KwikPen revised January 2026):
| Device | Sites you can inject yourself | Back of the upper arm | Device-specific step |
|---|---|---|---|
| Single-dose pen | Abdomen or thigh | Another person should give the injection | Place the clear base flat on the skin, unlock, press and hold the button up to 10 seconds; the second click means the injection is complete |
| KwikPen (4 weekly doses) | Abdomen at least 2 inches from the belly button, or thigh | Another person should give the injection | Prime before each weekly dose, push the dose knob in and slowly count to 5 while holding it |
| Single-dose vial | Abdomen or thigh | Another person can inject here | Use a new syringe and needle; keep the needle in the skin for at least 5 seconds |
| Multi-dose vial (4 doses) | Abdomen or thigh | Another person can inject here | Use a new syringe and needle each time; keep the needle in the skin for at least 5 seconds |
The label also notes that the KwikPen is not recommended for self-injection by people who are visually impaired unless their healthcare provider decides they can use it properly.
How do you inject tirzepatide, step by step?
The exact steps depend on the device, so follow the Instructions for Use that come in your carton. The common parts, in the order Lilly's instructions give them, are:
- Check the label for the right medicine and dose, and that it has not expired. The liquid should be clear and colorless to slightly yellow, not frozen or cloudy, and without particles.
- Wash your hands with soap and water.
- Choose the injection site: abdomen or thigh yourself, or the back of the upper arm with help. Use a different spot from last week.
- Give the injection as the device instructions describe. With a vial, the instructions say your healthcare provider should tell you whether to pinch the skin first.
- If you see blood afterwards, press the site lightly with gauze or a cotton ball. Do not rub it.
- Put used pens, needles and syringes in an FDA-cleared sharps container right away.
The label says Zepbound is taken once a week, at any time of day, with or without meals. The dose starts at 2.5 mg and can rise in steps to a maximum of 15 mg a week; your prescriber sets each step.
Where should you not inject Zepbound?
Even within the approved Zepbound injection sites, some skin should be skipped. Both vial instructions list it:
- Skin with pits, that is thickened, or that has lumps.
- Skin that is tender, bruised, scaly or hard.
- Scars or damaged skin.
- The same spot you use for another injected medicine.
They also say not to mix Zepbound with any other medicine. Across all devices, the Medication Guide says not to inject into a muscle or a vein. The KwikPen instructions say not to share the pen with other people, even if the pen needle has been changed, and the vial instructions say not to share needles or syringes.
How common are injection site reactions with Zepbound?
In the two weight-loss trials pooled in the Zepbound label, injection site reactions were reported by 6% of people on 5 mg and 8% on 10 mg and 15 mg, against 2% on placebo. The label's definition groups several reactions: bruising, redness (erythema), itching (pruritus), pain, rash and other reactions at the injection site.
The label also reports that reactions were more frequent in people who developed antibodies to tirzepatide (11.3%) than in those who did not (1%).
The Mounjaro label, from trials in adults with type 2 diabetes, reports injection site reactions in 3.2% of people on Mounjaro against 0.4% on placebo. The two labels come from different trials and populations, so the numbers are not directly comparable.
These are separate from allergic reactions. The label lists serious allergic reactions among its warnings, and the Medication Guide says to stop using Zepbound and get medical help right away for swelling of the face, lips, tongue or throat, trouble breathing or swallowing, severe rash or itching, fainting or feeling dizzy, or a very rapid heartbeat.
What if you miss a Zepbound injection?
The label's rule is short. Take the missed dose as soon as possible within 4 days (96 hours). If more than 4 days have passed, skip it and take the next dose on your usual day. You can change your injection day as long as doses are at least 3 days (72 hours) apart. A missed dose changes when you inject, not where: rotate to a new site as usual.
Storing Zepbound before you inject
Storage affects the medicine, not the site, but the label's limits are worth knowing. Single-dose pens and vials are kept in the refrigerator and may be stored unrefrigerated at up to 86°F (30°C) for a total of 21 days. Opened multi-dose vials and KwikPens are thrown away after 30 days at room temperature, 30 days after first use, or after 4 weekly doses, even if medicine is left. Do not use any Zepbound that has been frozen.
The device you get depends on how you buy it. Lilly sells single-dose vials and KwikPens directly to self-pay patients, and some online clinics, such as Shed (see our Shed review), list Zepbound among their prescriptions. The Zepbound injection sites are the same either way. For prices and routes, read how to get Zepbound without insurance, and for what tirzepatide is and how it compares, see our tirzepatide guide and semaglutide vs tirzepatide.
FAQ
Can I inject Zepbound into my arm myself? Lilly's single-dose pen and KwikPen instructions say another person should give the injection in the back of the upper arm. The abdomen and thigh are the sites for injecting yourself.
Is it better to inject Zepbound in the stomach or the thigh? The label says exposure to tirzepatide was similar from the abdomen, thigh and upper arm, so neither site makes a dose stronger. Pick the one you can reach and see comfortably, and rotate.
Can I use the same spot every week? No. Zepbound injection sites should be rotated. The label says to rotate injection sites with each dose. You may stay in the same area, such as the abdomen, but use a different spot within it each week.
How far from the belly button should I inject Zepbound? The KwikPen instructions say at least 2 inches from the belly button.
Are Zepbound and Mounjaro injected in the same places? Yes. Both labels name the abdomen, the thigh, and the back of the upper arm when another person injects, so the Zepbound injection sites and the Mounjaro ones are the same.
Is redness or itching at the injection site normal? Injection site reactions, including redness, itching, bruising, pain and rash, were reported by 6% to 8% of people on Zepbound in the weight-loss trials, against 2% on placebo. Tell your prescriber about any reaction that bothers you or does not go away, and get help right away for signs of a serious allergic reaction.
Sources
- Zepbound label on DailyMed, revised August 2026
- Mounjaro label on DailyMed, revised August 2026
Both labels, with their Instructions for Use, read 21 October 2026.
Related reading
- Zepbound insurance coverage
- How to get Zepbound without insurance
- Semaglutide vs tirzepatide
- Tirzepatide: prices and clinics
- Zepbound side effects and dosage
- How Zepbound works
- Does Zepbound need to be refrigerated?
- Zepbound and alcohol
- How long Zepbound stays in your system
