# Headaches and dizziness

> Wegovy’s leaflet lists headache as very common and feeling dizzy as common; Ozempic’s lists both as common. Mounjaro’s lists dizziness as common for weight management. In two Zepbound trials, 4% to 5% reported dizziness, against 2% on placebo. Mounjaro’s lists both as signs of low blood sugar.

Canonical: https://jabwise.app/guides/headaches-and-dizziness. Sources checked 12 October 2026. General information, not medical advice: follow your prescriber.

## How common it is

Each leaflet’s own words for how common each is, quoted as written. Zepbound’s figures are the share of people in its two weight trials.

- **Mounjaro**: Headache: Listed only as a sign of low blood sugar; Dizziness: "Dizziness observed in patients treated for weight management" ([Mounjaro KwikPen patient leaflet](https://www.medicines.org.uk/emc/product/15481/pil))
- **Zepbound**: Headache: Not in its table of common side effects; Dizziness: 4% to 5%, against 2% on placebo
- **Wegovy**: Headache: "Very common: may affect more than 1 in 10 people" ([Wegovy FlexTouch patient leaflet](https://www.medicines.org.uk/emc/product/13800/pil)); Dizziness: "Common: may affect up to 1 in 10 people" ([Wegovy FlexTouch patient leaflet](https://www.medicines.org.uk/emc/product/13800/pil))
- **Ozempic**: Headache: "Common (may affect up to 1 in 10 people)" ([Ozempic patient leaflet](https://www.medicines.org.uk/emc/product/9748/pil)); Dizziness: "Common (may affect up to 1 in 10 people)" ([Ozempic patient leaflet](https://www.medicines.org.uk/emc/product/9748/pil))

## What else they say

- **Mainly at the start**: Wegovy’s leaflet says some people may feel dizzy when taking it, mainly during the first 3 months of treatment.
- **Driving**: The NHS says if you feel dizzy after using it, don’t drive, ride a bike or use machinery until it has gone away.
- **Low blood sugar**: Mounjaro’s leaflet lists headache and dizziness among signs of low blood sugar, likelier with insulin or a sulphonylurea.
- **On standing up**: Wegovy’s leaflet lists feeling dizzy or lightheaded on standing or sitting up, from a drop in blood pressure, as uncommon.

## Questions

### Does Wegovy cause headaches?

Wegovy’s leaflet lists headache as very common, more than 1 in 10 people, and says its very common side effects usually go away over time.

### Does Mounjaro cause dizziness?

Mounjaro’s leaflet lists dizziness as common in people treated for weight management, up to 1 in 10. It also lists dizziness as a possible sign of low blood sugar.

### When should I get help?

The NHS says speak to a pharmacist or doctor if a side effect bothers you or doesn’t go away, and call 111 if you think you’re having a serious one.

## In Jabwise: Side effects

Count the days it’s there. Headache and Dizziness are each one tap in a check-in. Side Effects counts the days you felt each, over 7, 30 or 90 days, ready for your next review.

## 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)
- [Zepbound prescribing information](https://uspl.lilly.com/zepbound/zepbound.html)
- [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: Tirzepatide](https://www.nhs.uk/medicines/tirzepatide/)
- [NHS: Semaglutide](https://www.nhs.uk/medicines/semaglutide/)