Semaglutide Pen and Other GLP-1 Pens: Types and Needles
In this guide
This article is for information only and is not medical advice. Talk to your prescriber or a qualified professional.
A semaglutide pen (Wegovy or Ozempic) or a tirzepatide pen (Zepbound or Mounjaro) is a prefilled injector you use under the skin once a week. There are two basic designs. A single-dose pen holds one dose, has a built-in hidden needle and is thrown away after one use. A multi-dose pen holds several weekly doses and needs a new pen needle attached each time. This guide restates what the current FDA labels and Instructions for Use (IFUs) say about each pen.
About Dosinha: a shot log, reminders, injection-site rotation, weight and water are free forever. See what is free and what Pro adds.
Key points
- Single-dose pens: one dose, needle built in, discard after use.
- Multi-dose pens: 4 weekly doses (Ozempic pens vary), attach a new needle every time.
- The labels and Medication Guides say never share a pen, even if the needle is changed.
- The IFU for your exact pen is the authority. The labels say you should be trained on it before you start.
The two kinds of GLP-1 pen
| Pen | Type | Needle | After use, per the label or IFU |
|---|---|---|---|
| Wegovy single-dose pen | One dose, dose already set | Built in, covered and not seen | Discard after use |
| Wegovy FlexTouch | Single-patient-use, 4 doses of 2.4 mg | Attach a new needle each time (included) | Store without a needle, up to 56 days after first use |
| Ozempic pen | Single-patient-use, multiple weekly doses | Attach a new needle each time (included) | Discard 56 days after first use, even with medicine left |
| Zepbound and Mounjaro single-dose pens | One dose | Built in, under a gray base cap | Discard after use |
| Zepbound and Mounjaro KwikPen | Single-patient-use, 4 fixed weekly doses | Attach a new KwikPen-compatible pen needle (not included) | Discard 30 days after first use or after 4 doses |
The labels also list vials or syringes, which use a different technique and are not covered here. For where to inject and how to rotate, see our injection site rotation guide.
Single-dose pens
Wegovy single-dose pen
People often search for an “auto injector pen for semaglutide.” The Wegovy label calls it a prefilled single-dose pen. According to its IFU, the dose is already set, the needle is covered by a needle cover and you will not see it, and the injection starts when you press the needle cover firmly against your skin. Cartons hold 4 pens.
The label says to store the pens in the refrigerator, and that before the cap is removed a pen can be kept between 46°F and 86°F (8°C to 30°C) for up to 28 days if needed.
Zepbound and Mounjaro single-dose pens
The tirzepatide single-dose pen IFUs describe a pen with a gray base cap over the needle and a lock ring. The labels say each pen can be kept at room temperature up to 86°F (30°C) for a total of 21 days if needed, and should be thrown away after that.
Multi-dose pens
Ozempic pen
The Ozempic label lists three pens, each holding several weekly doses: one that delivers 0.25 mg or 0.5 mg doses, one for 1 mg doses and one for 2 mg doses. The IFU says to check the flow before the first injection with each new pen only, to use a new needle for every injection, and never to use a syringe to draw medicine out of the pen. Once in use, the pen can be kept at room temperature (59°F to 86°F, 15°C to 30°C) or in the refrigerator, and is thrown away after 56 days even if medicine is left.
Wegovy FlexTouch
The FlexTouch IFU describes a pen with 4 fixed doses of 2.4 mg, one each week. After first use, the label says it can be stored for 56 days at room temperature or in the refrigerator, always without a needle attached.
Zepbound and Mounjaro KwikPen
The KwikPen IFUs describe a pen with 4 fixed weekly doses. You attach a new pen needle, prime before each weekly injection, then turn the dose knob all the way until it stops. The IFUs say to throw the pen away 30 days after first use or after 4 weekly doses, even if medicine is left, and not to transfer medicine into a syringe.
For the injection steps themselves, see how to inject a GLP-1 in the stomach.
What size needle is used for a GLP-1 injection
This depends on the pen:
- Single-dose pens (Wegovy, Zepbound, Mounjaro): the needle is built in. There is nothing to choose.
- Ozempic pen and Wegovy FlexTouch: the IFUs say 32G, 4 mm disposable needles come in the box. If you need more, the IFUs say compatible disposable needles up to 8 mm long can be used, and to talk to your healthcare professional about compatibility.
- Zepbound and Mounjaro KwikPen: the IFUs list a KwikPen-compatible pen needle, not included, and do not give a length. Ask your pharmacist which needles fit your pen.
The Zepbound KwikPen IFU says a new needle each time helps prevent infections and blocked needles.
Rules that apply to every pen
- Never share a pen. The labels say the multi-dose pens must never be shared, even if the needle is changed, because of the risk of passing blood-borne infections. The Medication Guides say not to share your pen with other people.
- Check before each use. The IFUs say to check the pen and its label before you inject, and to look at the medicine. Wegovy and Ozempic should be clear and colorless. Zepbound and Mounjaro should be colorless to slightly yellow. Do not use a pen that was frozen.
- Use a sharps container. The IFUs say to put used pens and needles in a sharps disposal container right away.
- Vision. The labels say the Wegovy FlexTouch and the KwikPens are not recommended for self-injection by people who are visually impaired, and the Ozempic IFU says not to use its pen without help if you cannot read the dose counter.
The Wegovy, Zepbound and Mounjaro labels say you should be retrained if your pen changes, so ask before you inject if a refill looks different. For dose questions, see GLP-1 dosage: what the labels say. Your prescriber and pharmacist set your plan.
When to call a clinician
Call your pharmacist or the number in your IFU if the pen does not behave as the IFU describes. Do not inject a second time without checking first.
When to call: The Medication Guides for all four medicines say to get medical help right away for signs of a serious allergic reaction, such as swelling of the face, lips, tongue or throat, problems breathing or swallowing, or severe rash or itching. They also say to stop using the medicine and call right away for severe stomach pain that will not go away.
Frequently asked questions
What is a GLP-1 injection pen?
It is a prefilled injector for a GLP-1 medicine, used under the skin once a week. Some hold one dose with a built-in needle, others several doses with a new needle each time.
Is the Wegovy pen an autoinjector?
The label calls it a prefilled single-dose pen. Its IFU says the dose is already set and the injection starts when you press the needle cover firmly against your skin.
What size needle comes with the Ozempic pen?
The Ozempic IFU says 32G, 4 mm needles are included, and that compatible disposable needles up to 8 mm can be used. Ask your healthcare professional about compatibility.
Keep track of each pen
Dosinha’s shot log records the date and site of every dose, and reminders keep your weekly day. Because every shot is dated, you can count back to the day you started your current multi-dose pen and check it against your IFU. The shot log, reminders and site rotation map are free. Try the free log.
Sources
- DailyMed. Wegovy prescribing information and Instructions for Use (single-dose pen and FlexTouch), sections 2.1, 3, 5.11 and 16. Novo Nordisk, label revised June 2026.
- DailyMed. Ozempic prescribing information and Instructions for Use, sections 3, 5.4 and 16. Novo Nordisk, label revised June 2026.
- DailyMed. Zepbound prescribing information and Instructions for Use (single-dose pen and KwikPen), sections 2.4, 3, 5.10 and 16. Eli Lilly, label revised August 2026.
- DailyMed. Mounjaro prescribing information and Instructions for Use (single-dose pen and KwikPen), sections 2.2, 3, 5.10 and 16. Eli Lilly, label revised August 2026.
This article is for information only and is not medical advice. Talk to your prescriber or a qualified professional.