# Red, itchy or sore where you inject

> The NHS lists itchy or red skin where you inject as a common side effect, and Mounjaro’s and Wegovy’s leaflets call injection site reactions common, up to 1 in 10 people. The NHS lists an allergic reaction as serious, with symptoms such as a swollen throat or tongue, a raised, itchy rash or difficulty breathing.

Canonical: https://jabwise.app/guides/reactions-where-you-inject. Sources checked 12 October 2026. General information, not medical advice: follow your prescriber.

## In their own words

What each source lists as injection site reactions, and how often it says they happen.

- **Mounjaro**: What it lists: "Injection site reactions (e.g. itching or redness)" ([Mounjaro KwikPen patient leaflet](https://www.medicines.org.uk/emc/product/15481/pil)); How often: "Common (may affect up to 1 in 10 people)" ([Mounjaro KwikPen patient leaflet](https://www.medicines.org.uk/emc/product/15481/pil))
- **Wegovy**: What it lists: "injection site reactions" ([Wegovy FlexTouch patient leaflet](https://www.medicines.org.uk/emc/product/13800/pil)); How often: "Common: may affect up to 1 in 10 people" ([Wegovy FlexTouch patient leaflet](https://www.medicines.org.uk/emc/product/13800/pil))
- **Ozempic**: What it lists: "such as bruising, pain, irritation, itching and rash" ([Ozempic patient leaflet](https://www.medicines.org.uk/emc/product/9748/pil)); How often: "Uncommon (may affect up to 1 in 100 people)" ([Ozempic patient leaflet](https://www.medicines.org.uk/emc/product/9748/pil))
- **NHS**: What it lists: "itchy or red skin where you inject" ([NHS: Semaglutide](https://www.nhs.uk/medicines/semaglutide/)); How often: Common for both

## Worth knowing

- **A new spot each week**: The NHS says change the place you inject each week; the same area is fine, just not the exact same spot each time.
- **On darker skin**: The NHS lists itchy or red skin where you inject, and notes redness may be harder to see on brown or black skin.
- **A little blood**: If blood appears where you injected, Wegovy’s and Ozempic’s patient leaflets say press lightly on the spot.
- **Pain where you inject**: Mounjaro’s leaflet lists injection site pain as an uncommon side effect, which may affect up to 1 in 100 people.

## Questions

### Is a red, itchy patch normal?

The NHS lists itchy or red skin where you inject among the common side effects, and says speak to a pharmacist or doctor if a side effect bothers you or does not go away.

### When is it something more serious?

The NHS lists an allergic reaction among the serious side effects, with symptoms such as a swollen throat or tongue, a raised, itchy rash or difficulty breathing. The NHS says call 111 if you think you might be having serious side effects.

### Does moving the spot help?

The sources don’t say it prevents reactions. They do say to change the spot each time: the NHS each week, Mounjaro’s leaflet, if you use the same area, a different spot within it, and Wegovy’s not the same spot as last time.

## In Jabwise: Injection areas

Jabwise suggests where to inject next. Log the area with each jab and Jabwise suggests the one you’ve used longest ago, on a simple body map, so moving the spot each week takes no remembering.

## Getting real advice

- **A pharmacist, your doctor or NHS 111**: If you’re not sure how to use your medicine, or a side effect bothers you or won’t go away. NHS 111 if you think you might be having serious side effects, or you’ve used too much. [NHS: Semaglutide](https://www.nhs.uk/medicines/semaglutide/), [NHS: Tirzepatide](https://www.nhs.uk/medicines/tirzepatide/), [NHS 111 online](https://111.nhs.uk/)
- **Report a side effect**: Anyone can, not only doctors. [Yellow Card (UK)](https://yellowcard.mhra.gov.uk/), [MedWatch (US)](https://www.fda.gov/safety/medwatch-fda-safety-information-and-adverse-event-reporting-program)

## Sources

- [Mounjaro KwikPen patient leaflet](https://www.medicines.org.uk/emc/product/15481/pil)
- [Wegovy FlexTouch patient leaflet](https://www.medicines.org.uk/emc/product/13800/pil)
- [Ozempic patient leaflet](https://www.medicines.org.uk/emc/product/9748/pil)
- [NHS: Semaglutide](https://www.nhs.uk/medicines/semaglutide/)
- [NHS: Tirzepatide](https://www.nhs.uk/medicines/tirzepatide/)