How to manage Mounjaro and Wegovy side effects

Side effects are very common when starting Mounjaro or Wegovy, particularly in the first few weeks or after increasing the dose.^{1 2}.

One of the ways they help with weight loss is by slowing stomach emptying and helping you feel fuller for longer. While that can be incredibly helpful for reducing appetite, it can also be the cause of some less pleasant side effects.

The first few weeks can sometimes feel a bit like trial and error as you work out what your body tolerates best. You may find yourself eating smaller portions without trying, feeling full more quickly, or noticing that rich or heavy foods suddenly lose their appeal.

For most people, side effects improve as the body adapts. They are often most noticeable when treatment begins or when doses increase, then gradually settle over days to weeks.

The most common side effects are digestive, including:³⁴⁵

Some people also notice headaches, tiredness, dizziness, or mild irritation at the injection site.

Not everyone experiences side effects, and their severity varies from person to person. Symptoms may come and go, and it’s not uncommon to notice new side effects after a dose increase.

You may also find that rich meals, greasy foods, alcohol, and large portions are harder to tolerate than before.

Some patients report fewer digestive side effects with Mounjaro than Wegovy, particularly nausea, although it is impossible to predict how any individual will respond.

The good news is that small adjustments often make a surprisingly big difference.

Eat smaller meals and eat slowly

This is probably the single most helpful change.

Try eating more slowly and stopping when you feel comfortably satisfied rather than full. Because these medications enhance fullness signals, eating too much or too quickly can leave you feeling uncomfortable, bloated, or nauseated.

Some people find it helpful to think in terms of “smaller and simpler” meals, especially early on.

Avoid heavy, rich, or greasy foods

Fatty foods, creamy meals, fried snacks, spicy dishes, and large portions are common triggers for nausea or diarrhoea.

That does not mean you can never enjoy these foods again, but in the early weeks it is often worth keeping things relatively gentle while your body adjusts.

It’s not uncommon with time that your desire for different types of food changes too.

You can find more information on what to eat in our articles, Mounjaro diet: Foods to eat and avoid and Wegovy diet: Foods to eat and avoid.

Stay hydrated

If you are eating less or experiencing diarrhoea or vomiting, dehydration can cause trouble surprisingly quickly and contribute to headaches, dizziness, constipation, and fatigue.

Small, regular sips are often easier than trying to drink a large amount at once. Some people find cold drinks, diluted squash, electrolyte drinks or herbal teas easier if nausea is an issue.

Increase fibre gradually to prevent constipation

Constipation is very common with both Wegovy and Mounjaro. Gentle movement such as walking, good hydration, and gradually increasing fibre can help.

Foods such as oats, fruit, vegetables, beans, lentils, nuts, seeds, and linseeds can help to keep things moving. However, suddenly eating a huge amount of fibre can worsen bloating and discomfort, so it’s best to build this up over time.

Stay upright after eating to reduce reflux

This can be particularly troublesome if you already suffer with acid reflux. Keeping portion sizes small, staying upright after meals, and limiting fizzy and caffeinated drinks, and spicy foods can go a long way to improving these symptoms.

Eat little and often if nausea is an issue

Some people find simple things such as ginger chews or peppermint helpful for mild nausea. Keeping food cold and bland can also be easier to tolerate than hot or strongly flavoured meals.

Although you might not fancy much if you’re struggling with nausea, eating little and often rather than allowing yourself to become very hungry can help, as an empty stomach sometimes worsens nausea.

Eating slowly, fresh air, or a gentle walk can help settle mild nausea too.

If nausea is significant, persistent, or stopping you from eating properly, it’s important to check in with your doctor. Sometimes medications to help with nausea can be prescribed where appropriate.

Take medication to help

Most side effects are mild and improve with time and simple adjustments. However, there are occasions when medication may be helpful, particularly if symptoms are affecting your ability to function normally, eat, drink, or continue treatment comfortably.

For example, persistent nausea or vomiting may sometimes be helped by anti-sickness medication. Reflux or indigestion may improve with medicines that reduce stomach acid. Constipation can occasionally require laxatives, especially if increasing fluids, fibre, and movement are not enough.

Some people also benefit from slowing dose increases, staying on a lower dose for longer, or occasionally stepping back temporarily if symptoms have become difficult to tolerate.

Don’t rush the dose increases

One of the biggest misconceptions is that faster dose increases mean faster success.

Actually, for many people, staying on a lower dose for longer can reduce side effects, and still lead to excellent results. If you can’t tolerate a medication then you’ll be unlikely to stick with it in the longer term.

A good provider should help you find the lowest effective dose for you, rather than simply escalating automatically. Side effects are one of the reasons ongoing medical oversight matters.

For most people, side effects are temporary and improve as the body adapts to treatment. Symptoms are often most noticeable during the first few weeks after starting Mounjaro or Wegovy, or after increasing the dose. You may even find that symptoms come and go rather than following a predictable pattern.

Although everyone’s experience is different, side effects often become easier to manage with time.

In most cases, no. Mild side effects are common and do not usually mean that you need to stop treatments. Symptoms usually improve with time, simple dietary changes, or by slowing dose increases.

If side effects are affecting your ability to eat, drink, or carry out normal daily activities, speak to your healthcare provider before stopping treatment, as there may be ways to make the medication easier to tolerate.

Most people who experience mild or moderate side effects are able to continue treatment successfully with the right support, a little patience, and sometimes some simple adjustments along the way.

Most side effects are common and often manageable at home, with or without over-the-counter medications. But it is important to know when symptoms may need medical review.

You should speak to your healthcare provider if:

• Side effects are marked or persistent.

• You are struggling to eat or drink properly.

• Symptoms are affecting work or daily life.

• You feel symptoms are worsening rather than improving.

• Constipation, diarrhoea, or vomiting is becoming difficult to manage.

Side effects when using Mounjaro and Wegovy are common, but struggling alone should not be.

If you’re choosing a private provider it is worth finding out what support they are able to offer you if you are experiencing side effects.

With the right support, practical adjustments, and sometimes a little patience, many people find that symptoms settle and treatment becomes much easier to manage.

Finally, although rare, if you do experience severe side effects, do not delay seeking medical attention.