Ozempic side effects: risks and what you should know

Ozempic is an injectable medication designed to treat type 2 diabetes. It belongs to a group of medications called glucagon-like peptide-1 (GLP-1) receptor agonists, which work by mimicking a natural hormone that helps regulate blood sugar levels and appetite.

Because Ozempic slows how quickly food leaves your stomach (gastric emptying) and affects insulin release, some people may get side effects while their bodies adjust.

This guide explains the most common Ozempic side effects, how long they can last, and how to manage them.

ZAVA Online Doctor does not prescribe Ozempic for weight loss, however we do offer Wegovy. Wegovy is similar to Ozempic, containing the same active ingredient (semaglutide), but it is an approved weight loss injection in the UK. Find information about Wegovy and its side effects.

Ozempic, like all medications, can have side effects. Not everyone who takes it will get side effects and most of the common ones are mild and not serious. However, they can be uncomfortable or unpleasant.

There are also some more serious side effects of semaglutide medications like Ozempic. While serious side effects are uncommon or rare, they can potentially be life-threatening so you should be aware of them.

How is a ‘common’ side effect defined?

According to BNF medication guidance:

• very common side effects impact more than 1 in 10 users
• common side effects affect up to 1 in 10
• rare side effects affect fewer than 1 in 1,000

We’ll apply these categories when exploring Ozempic side effects.

What are the common side effects of Ozempic?

Many of the most common side effects of Ozempic cause gastrointestinal symptoms like nausea, bloating, or changes in bowel movements. This is because of the way semaglutide medications slow down diestion and delay how quickly your stomach empties.

Very common side effects, which will affect more than 1 in 10 people taking Ozempic, include:

• nausea (feeling sick)
• diarrhoea
• constipation
• low blood sugar (hypoglycaemia), when Ozempic is used with other medications to lower blood sugar such as insulin*

Other common side effects of Ozempic that may affect up to 1 in 10 people include:

• vomiting (being sick)
• dizziness
• tiredness
• weight loss
• heartburn, reflux, or indigestion (gastrointestinal discomfort)
• gas (flatulence)
• burping
• gallstones
• bloated or inflamed stomach (gastritis)
• increase of pancreatic enzymes (such as lipase and amylase)

* Although hypoglycaemia is most often seen in people with type 2 diabetes, it can occasionally occur in non-diabetic people taking semaglutide for weight management, such as with Wegovy. This is why it’s important to be aware of symptoms like dizziness, sweating, or feeling faint – even if you’re not using semaglutide for diabetes.

What are the mild side effects of Ozempic?

Ozempic side effects are often mild and they should not make you too uncomfortable.

The mild side effects of Ozempic include:

• nausea
• constipation or diarrhoea
• heartburn or indigestion
• injection site itching or soreness

These mild side effects should be manageable at home without treatment. We’ve suggested ways to improve the discomfort you experience in the “How can I manage Ozempic side effects?” section of this page. But if any side effects become unmanageable or too uncomfortable you should speak to your doctor.

What are the serious side effects of Ozempic?

Ozempic can have some serious side effects. These are usually uncommon or rare but can potentially be life-threatening.

Serious Ozempic side effects include:

• complications of diabetic eye disease (retinopathy) – speak to your doctor if you experience any eye problems or changes in vision while taking Ozempic
• pancreatitis (inflammation of the pancreas causing severe abdominal pain that does not go away)
• gallbladder problems, such as gallstones or inflammation (cholecystitis)
• a serious allergic reaction (anaphylaxis or angioedema) – this is rare and may cause breathing difficulties (breathlessness or wheezing) or swelling of the mouth, throat, tongue, face, or lips
• pulmonary aspiration during general anaesthesia or deep sedation. If you are scheduled for surgery, tell your anaesthetist that you are using a GLP-1 medication such as Ozempic

Please note: The information in this article is for educational purposes only. To see a complete list of Ozempic side effects by dose, please view the patient information leaflet.

Most side effects of Ozempic – including symptoms such as nausea, diarrhoea, or constipation – will go away on their own after a few days or weeks. Ozempic side effects are usually mild and short-term, and most people are able to tolerate them at home without treatment.

When taking Ozempic, you will follow a gradually increasing dosing schedule. This is to allow you to adjust to the treatment slowly. You may find that you experience more side effects when you first start taking Ozempic as your body is getting used to the medication.

Side effects may also come back or become more intense after each injection. Despite this, most side effects should get better over time when you reach your maintenance dose and your blood sugar is under control.

If you have side effects that do not go away and you find it difficult to manage, talk to your doctor.

Tip: Sip water regularly and eat small, plain meals while adjusting to your dose.

When do Ozempic side effects start?

Most people experience side effects within the first few weeks of starting treatment as their bodies adjust to the medication.

Can Ozempic cause long-term side effects?

Long-term side effects from Ozempic are unknown. Ozempic is still a relatively new medication, so more research is needed to study its long-term effects.

A 2-year study on weekly semaglutide (Ozempic) injections found no evidence of rare and serious side effects, such as pancreatitis, but more research is necessary to confirm the link between long-term Ozempic use and these conditions.

The Medicines and Healthcare products Regulatory Agency (MHRA) and British National Formulary (BNF) confirm that semaglutide is safe when prescribed appropriately (for type 2 diabetes) and monitored by a healthcare professional. However, misuse or obtaining Ozempic from unregulated sources can increase the risk of serious side effects.

Although Ozempic is not known to cause long-term side effects directly, some side effects could cause long-term health problems, if not treated early. This includes:

• pancreatitis
• gallstones
• low blood sugar (if ongoing)
• dehydration caused by severe vomiting and diarrhoea
• kidney impairment or failure
• bowel obstruction

They can. Some people find that their side effects do get worse as they move to a higher dose. This is normal as your body adjusts to the higher levels of the medication. You will adapt to these levels and side effects should subside in time.

When taking Ozempic, your doctor will adjust your dose as part of the normal dosing schedule of the medication.

If you find that your side effects are severe or uncomfortable, you may be able to reduce your dose. In this case, speak to your doctor about a reduced dose until side effects subside.

Most of Ozempic’s common side effects will go away on their own without treatment. If your side effects are uncomfortable, you might want to try the following ideas:

Nausea or vomiting

Nausea or vomiting are common side effects of Ozempic. They normally go away on their own as you get used to the medication.

You can try to avoid or alleviate nausea or vomiting by:

• drinking cold water in regular sips, not large gulps
• staying hydrated as vomiting can cause you to lose fluids
• getting plenty of air by taking deep breaths or going outside
• eating in small amounts regularly, avoiding large portions
• avoiding greasy, fatty foods as these can worsen symptoms of nausea
• avoid drinking or eating too quickly
• eat or drink foods containing ginger as it has natural medicinal properties that help with nausea

Gastrointestinal symptoms (heartburn, reflux, indigestion)

Gastrointestinal symptoms such as heartburn, acid reflux or indigestion are common side effects of Ozempic. While these symptoms are likely to be short-term they can be unpleasant.

You may be able to manage gastrointestinal symptoms by:

✓ avoiding food and drink that can worsen these symptoms (carbonated drinks, processed or fatty foods, spicy or fried foods, citrus fruits, and dairy products)

✓ treating heartburn and indigestion with over-the-counter medications like Rennie or Gaviscon

Constipation

Constipation can be a common side effect as your body adjusts to taking Ozempic. Although constipation is likely to be a short-term side effect, it can be uncomfortable.

You can manage constipation by:

✓ staying hydrated by drinking plenty of fluids

✓ increasing your intake of fibre gradually

✓ increasing the amount of physical activity you do may help you go to the toilet

✓ trying laxatives or constipation relief products if necessary, following the advice of your doctor

Injection site reactions

Ozempic is an injectable medication. This means that irritation and soreness may happen on the parts of your body where you inject it.

To reduce irritation and soreness at the injection site you could:

• try to choose a different section of your skin each time you inject Ozempic
• avoid certain areas of skin if you find that they are more sensitive to the injections
• take an antihistamine tablet or use an antihistamine cream before injecting

If you’re getting irritation at the injection site that does not settle down after a few days, you must let your doctor know.

Low blood sugar (hypoglycaemia)

Ozempic is a treatment for people with type 2 diabetes to help control blood sugar levels. However, blood sugar that is too low (hypoglycaemia) can be a side effect of using semaglutide medications like Ozempic as it works to lower blood sugar. You are more likely to experience low blood sugar on Ozempic if you are taking other medications to lower blood sugar, such as insulin. Your doctor may reduce your dose of these medications before you start taking Ozempic.

It is important to be aware of the signs of low blood sugar such as hunger, dizziness, cold sweats, shaking, and weakness. The doctor who prescribes your Ozempic should also tell you how to recognise the warning signs of low blood sugar and what to do.

To avoid low blood sugar while on Ozempic, you should:

✓ check your blood sugar regularly

✓ follow your treatment plan for diabetes carefully

✓ ensure you always have sugary sweets, drinks or glucose tablets to hand that will raise your blood sugar quickly should you get low blood sugar

✓ use a continuous glucose monitor

It is possible to treat low blood sugar yourself at home by eating or drinking something that will raise your blood sugar quickly, for example, sugary drinks or sweets.

However, it is important to speak to your doctor if you find that you experience low blood sugar as a side effect of Ozempic. It could be that your dosage needs to be adapted to suit you better.

Remember, if you experience symptoms that do not go away, or they start to affect your day-to-day life, speak to your doctor or pharmacist.

Ozempic can have some rarer and more serious side effects that you will not be able to manage at home. These side effects may also require treatment from a doctor or emergency medical help.

There are some rare but serious side effects of Ozempic that you must not ignore if you experience them, including:

• complications with diabetic retinopathy – see a doctor if you notice changes in your eyesight while taking Ozempic
• allergic reaction (anaphylaxis) signs, which include breathing difficulties (breathlessness or wheezing) or swelling of the mouth, throat, tongue, face, or lips – call 999 because this is a medical emergency
• pancreatitis (inflammation of the pancreas) causing severe and consistent pain in the stomach and abdomen, and nausea and/or vomiting

Certain activities and conditions may make Ozempic side effects worse or more likely.

Drinking alcohol

Alcohol does not interact directly with semaglutide (the active ingredient in Ozempic), but it may make you more likely to experience side effects of nausea or dizziness. Alcohol can also cause hypoglycaemia if you have diabetes, and taking semaglutide medications like Ozempic can also increase this risk.

Eating certain foods

Like with alcohol, there are not any foods that are known to interact directly with Ozempic. However, some foods will cause or worsen side effects such as diarrhoea and constipation. So, it’s best to try and cut back on foods like:

• processed foods
• foods high in fat
• fizzy drinks, including sugar-free ones
• white pasta and white bread
• caffeinated drinks, like coffee

Taking Ozempic incorrectly

In the UK, Ozempic is only licensed for the treatment of type 2 diabetes, and should not be used for any other purposes. You might have heard of people using Ozempic for weight loss, but it is not intended for this. Instead, you should use Wegovy for weight loss – it contains the same active ingredient (semaglutide) but in different doses.

You should also avoid purchasing Ozempic from unregistered or unofficial sources. The MHRA has warned about falsified or unsafe pens being sold online. You should only ever obtain Ozempic from a regulated pharmacy.

People sometimes take Ozempic incorrectly. For example, missing a dose or not following the dosage schedule. The dosage schedule for Ozempic is designed to slowly increase the amount of medication in your body so you have time to get used to it. Increasing your dosage without your doctor’s approval can lead to worse side effects.

What medications can you not take with Ozempic?

There are no medications that are completely unsafe to take with Ozempic in every case, but some treatments may require dose adjustments, closer monitoring, or extra caution.

These include:

Anticoagulants

These are medications to treat blood clots, such as warfarin or acenocoumarol. Because Ozempic slows how quickly food and medicines move through your stomach, it may alter the absorption of these oral anticoagulants.

If you are taking warfarin (or a similar drug), your doctor may ask you to have your international normalised ratio (INR) checked more frequently when starting Ozempic, to make sure your dose remains safe and effective.

Prescription medication for diabetes

Some diabetes medicines – especially sulfonylureas (like gliclazide or glipizide) or insulin – can increase the risk of low blood sugar when taken with Ozempic.

You will usually continue taking your other diabetes medications, but your doctor may need to reduce the dose when starting Ozempic to lower the chance of hypoglycaemia.

Insulin

Ozempic is not an alternative to insulin, so you will need to keep taking insulin. If you use insulin, your doctor might reduce your dose of insulin and tell you how to monitor your blood sugar more often to help you to avoid hyperglycemia (high blood sugar) and diabetic ketoacidosis (a complication of diabetes that occurs when the body cannot break down glucose because there is not enough insulin).

Important: Always tell your doctor about any prescription, over-the-counter, or herbal medicines you use before starting semaglutide.

What foods should I avoid when taking Ozempic?

There are no foods you must strictly avoid while taking Ozempic, but certain foods can worsen common side effects like nausea, reflux, diarrhoea, or constipation. Because semaglutide slows gastric emptying, heavier or harder-to-digest foods may stay in your stomach for longer and increase discomfort.

You may find it helpful to limit:

High fat or greasy foods

Examples include fried foods, takeaway meals, fast food, creamy sauces, and high-fat meats. These take longer to digest and can trigger or worsen nausea, reflux, or stomach upset.

Ultra-processed foods

Highly processed meals and snacks (pastries, ready meals, packaged snacks) can worsen bloating or irregular bowel movements because they are often high in fat, sugar and additives.

Foods high in sugar or simple carbohydrates

This includes sweets, cakes, biscuits, crisps, chips, white bread, and other rapidly absorbed carbs.

These can cause sharp blood sugar spikes followed by drops, which is especially important for people with diabetes or those using insulin or sulfonylureas.

Spicy foods

Chillies, hot sauces, curries, and heavily spiced meals may worsen heartburn or indigestion, which are common early side effects of semaglutide.

Fizzy, sugary or sweetened drinks

Cola, energy drinks, sweet sparkling waters and similar products can increase bloating and reflux. Sugary drinks can also cause blood sugar fluctuations.

Some foods – like high-fat, greasy, and ultra-processed foods – are harder to digest and remain in our stomachs longer meaning they can contribute to or worsen side effects of Ozempic like vomiting, diarrhoea, or constipation.

We also recommend avoiding:

• foods that are high in sugar or carbs, such as sweets and cakes, chips, crisps and bread
• spicy food
• fizzy sugary or sweetened drinks

“While everything is safe to eat in moderation on Ozempic, avoiding certain foods while taking it may help to improve any side effects or prevent you from experiencing them. Watching what you eat can also help manage blood sugar levels and, if your diabetes is related to your weight, support weight loss too.” – Dr Kathryn Basford, Medical Editor.

Managing and reducing the risk of side effects on Ozempic is not just about avoiding certain foods. There are also foods or eating habits that can help you improve or manage your side effects. Try to:

• eat smaller portions and eat little and often to avoid nausea, diarrhoea, or constipation
• eat more protein and fibre to avoid spikes in your blood sugar with carbs

Yes, side effects will go away if you stop taking Ozempic but you should not stop taking Ozempic without talking to your doctor first. If you stop using Ozempic, your blood sugar levels may rise.

If your doctor decides it is safe for you to stop your Ozempic treatment, your side effects should start to go away within a few weeks.

Ozempic has a half-life of approximately 1 week, meaning it will take your body 1 week to get rid of half of a dose). Semaglutide, Ozempic’s active ingredient, will be present in the circulation (bloodstream) for about 5 weeks after the last dose.

It is not possible to get Ozempic out of your system faster than around 5 weeks. Research trials show that during this timeframe Ozempic is gradually processed by the body (metabolised) and primarily leaves your system through urine and faeces.

If you experience any unmanageable side effects during this period, speak to your doctor.

Natural Weight Loss or "Ozempic Face": Demystifying A Social Media Phenomenon, National Library of Medicine [accessed 11 November 2025]

Two-year effects of semaglutide in adults with overweight or obesity: the STEP 5 trial, National Library of Medicine [accessed 11 November 2025]

Low blood sugar, (hypoglycaemia) NHS [accessed 11 November 2025]

Ozempic 0.25 mg solution for injection in pre-filled pen, emc [accessed 11 November 2025]

Efficacy and safety of once-weekly semaglutide 1.0mg vs once-daily liraglutide 1.2mg as add-on to 1-3 oral antidiabetic drugs in subjects with type 2 diabetes, National Library of Medicine [accessed 11 November 2025]

Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes, National Library of Medicine [accessed 11 November 2025]

GLP-1 receptor agonists: reminder of the potential side effects and to be aware of the potential for misuse, Gov.uk / MHRA [accessed 11 November 2025]

Semaglutide – BNF, National Institute for Health and Care Excellence (NICE) [accessed 11 November 2025]

An exploration of Ozempic, British Pharmacological Society [accessed 11 November 2025]