# Drinking enough when you feel sick

> Being sick and diarrhoea can dehydrate you, as every leaflet and label here says. Mounjaro’s says drink plenty of fluids; Wegovy’s and Ozempic’s add this is especially important with kidney problems. None gives an amount. Zepbound’s label says tell your healthcare provider right away if it doesn’t go away.

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

## In their own words

Why each leaflet raises it, and what it asks you to do, quoted as written.

- **Mounjaro**: Why: "When starting treatment with Mounjaro, in some cases you may experience loss of fluids/dehydration, e.g. due to vomiting, nausea and/or diarrhoea, which may lead to a decrease in kidney function." ([Mounjaro KwikPen patient leaflet](https://www.medicines.org.uk/emc/product/15481/pil)); What to do: "It is important to avoid dehydration by drinking plenty of fluids." ([Mounjaro KwikPen patient leaflet](https://www.medicines.org.uk/emc/product/15481/pil))
- **Zepbound**: Why: "Diarrhea, nausea, and vomiting may cause a loss of fluids (dehydration) which may cause kidney problems." ([Zepbound prescribing information](https://uspl.lilly.com/zepbound/zepbound.html)); What to do: "It is important for you to drink fluids to help reduce your chance of dehydration." ([Zepbound prescribing information](https://uspl.lilly.com/zepbound/zepbound.html))
- **Wegovy**: Why: "These side effects can cause dehydration (loss of fluids)." ([Wegovy FlexTouch patient leaflet](https://www.medicines.org.uk/emc/product/13800/pil)); What to do: "It is important that you drink enough fluids to prevent dehydration." ([Wegovy FlexTouch patient leaflet](https://www.medicines.org.uk/emc/product/13800/pil))
- **Ozempic**: Why: "These side effects can cause dehydration (loss of fluids)." ([Ozempic patient leaflet](https://www.medicines.org.uk/emc/product/9748/pil)); What to do: "It is important that you drink plenty of fluids to prevent dehydration." ([Ozempic patient leaflet](https://www.medicines.org.uk/emc/product/9748/pil))

## What else they say

- **Early on**: Mounjaro’s leaflet says that, in some cases, fluids can be lost when you start treatment, through sickness or diarrhoea.
- **Kidney problems**: Wegovy and Ozempic say drinking enough fluids to avoid dehydration matters especially if you have kidney problems.
- **When it won’t stop**: Zepbound’s label says tell your healthcare provider right away about nausea, vomiting or diarrhoea that does not go away.
- **No set amount**: None of the leaflets, nor Zepbound’s label, gives a set number of glasses or litres to drink. A pharmacist can help.

## Questions

### How much should I drink?

The leaflets don’t give an amount. Mounjaro’s and Ozempic’s say plenty of fluids, and Wegovy’s says enough. A pharmacist can help if you’re not sure.

### Does it have to be water?

The leaflets say fluids, not water in particular. On alcohol, the NHS says it can increase side effects like feeling or being sick, so it’s best not to drink it.

### When should I get help?

The NHS says to speak to a pharmacist or doctor if you have side effects that bother you or do not go away. Zepbound’s label says tell your healthcare provider right away if nausea, vomiting or diarrhoea does not go away.

## In Jabwise: Water and steps

Jabwise counts every glass. Tap the plus on the water pill to log a glass or a bottle. Water shows today against a goal you set, your streak and the last two weeks, and water from Apple Health counts too if you connect it.

## 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: Semaglutide](https://www.nhs.uk/medicines/semaglutide/)
- [NHS: Tirzepatide](https://www.nhs.uk/medicines/tirzepatide/)