Nausea with Ozempic, Mounjaro or Wegovy: how food can help

Why do GLP-1 medicines cause nausea?

GLP-1 medicines slow gastric emptying, meaning food stays in the stomach for longer and this helps you feel full [1]. The same slowing explains much of the nausea. The medicine also acts on areas of the brain that regulate appetite, which is why you may sometimes have very little appetite [1]. Our GLP-1 medicines guide explains how each one works.

In trials of semaglutide at a dose of 2.4 mg (Wegovy), nausea occurred in 43.9% of people, compared with 16.1% taking placebo [2]. With tirzepatide (Mounjaro), it occurred in around 28%, compared with 8% taking placebo [1].

Digestive symptoms were almost always mild or moderate [3]. These are group figures, and symptoms vary considerably from person to person.

Does it get worse when the dose increases?

Yes. Digestive symptoms tend to cluster during dose escalation, both with semaglutide [2] and tirzepatide [3]. In semaglutide trials, nausea peaked at around week 20, shortly after people reached the full dose, and then eased [2].

If you notice your symptoms flaring up just after each increase, tell the person who prescribes your medicine. Sometimes they may keep you on a dose step for longer before moving to the next one. This is a medical decision, as we do not prescribe or change your dose.

How long does it last?

In semaglutide trials, each episode of nausea lasted a median of 8 days, and most episodes were temporary [2]. A small proportion of people continue to have digestive symptoms for much of their treatment, although these are almost always milder than at the start [2].

If you have been on the same dose for months and your nausea is not easing, or is getting worse, speak to your doctor. There is no benefit in suffering in silence.

Which foods are harder to tolerate?

Large, high-fat meals are usually the hardest to tolerate. Fat slows the emptying of a stomach that is already working more slowly, and a large meal fills it all at once [1]. A plate of fried food, a stew with lots of sauce or a very large portion eaten in one sitting are the examples we hear about most in consultations.

Early in treatment, large amounts of fibre may also be harder to tolerate [1]. You can leave whole pulses and plenty of raw vegetables until the nausea has eased. If you are also finding it difficult to open your bowels, our guide to constipation with a GLP-1 explains how to gradually increase your fibre again.

What is easier to tolerate?

It often helps to eat little and often. Have a small breakfast, followed by small meals every three to four hours, and drink enough [1]. Foods that are easy to digest and have a high water content, such as soups, purées, fruit or cooked vegetables, leave the stomach sooner [1].

Spreading food out in this way also helps you get the protein you need on a day when you have little appetite. You could organise a difficult day like this:

1. Start with fluids: have a few sips of water or broth when you get up.
2. Have a small, dry breakfast, such as toast or a rusk.
3. Every three to four hours, have something small containing protein, such as fresh cheese, egg or white fish.
4. Save the more elaborate meal for the time of day when you feel best.
5. Have an early, light supper.

If you would like to see a whole week of meals planned this way, take a look at what to eat with GLP-1 and a weekly meal plan.

Are high-protein yoghurts enough?

A high-protein yoghurt is a sensible option when you cannot manage a full meal. It is small, mild and provides protein with little effort, which is why it is so often recommended.

You do not have to stick to yoghurt. Broth with beaten egg, vegetable purée with blended pulses, or a small portion of white fish can serve the same purpose and offer more variety. If you have eaten only yoghurt for several days in a row, ask for help to try other gentle textures.

What we see in consultations

The most common mistake is to confuse “I am not hungry today” with “I cannot eat anything”. There is almost always some gentle food you can manage, even if only a small amount.

We also see people skip meals to avoid nausea. Nausea often gets worse when the stomach has been empty for hours, and then a large meal comes along and is harder to tolerate. Some people stop drinking water because they are afraid it will make the nausea worse, just when they need fluids most.

Are there days when nausea is worse?

Some people notice more nausea on certain days of the week, but the pattern varies. Make a note of when it happens so you can discuss it with your team and adapt your meals to what you can tolerate.

If you find that some days are worse, prepare gentle meals in advance for those days. Save the dishes you most fancy for when you feel better.

Does food temperature make a difference?

In consultations, we find that cold or lukewarm dishes are often easier to manage than very hot, freshly cooked food, perhaps because they smell less. A chilled courgette soup, lukewarm rice or a fruit salad may be easier to tolerate than a steaming stew on a difficult day.

If nausea makes it hard to drink

Nausea, vomiting and diarrhoea can cause dehydration, which in rare cases can affect the kidneys [4]. So, on a difficult day, looking after your fluid intake comes first. Small, frequent sips of water, broth or herbal tea are often easier to manage than a whole glass at once.

If you still cannot keep fluids down, do not wait until your next scheduled appointment. The specific warning signs are listed in the section “When to seek medical advice”.