Thinking about trying Ozempic® to help with weight loss? As well as wondering what sort of results you might expect, you also might be curious about whether you’ll experience any side effects.  

All medication comes with side effects, and with Ozempic®, they’re fairly common but are usually nothing to worry about. Mostly, Ozempic® side effects are related to the drug’s effect on the gut, although symptoms elsewhere in the body have been reported, too.  

Whether you’re new to Ozempic® or are still deciding whether it’s right for you, we’ve broken down what you need to know about its side effects—and what you can do about them.  

Common side effects of Ozempic®

Below are the most reported side effects of Ozempic®. They’re thought to impact up to one in ten people who take the drug.


Described as an uncomfortable sensation where you feel like you need to be sick, nausea was the most common side effect reported in clinical trials looking at how semaglutide, the active ingredient in Ozempic®, can help with weight loss. Usually though, this was mild or moderate and went away by itself.  

Ozempic® is thought to cause nausea because of how the drug works to slow the movement of food through the digestive system. This keeps us feeling fuller for longer, but it can also disrupt the stomach’s regular rhythm—which can bring on the feeling of nausea.

However, Ozempic® can also communicate with the brain to tell it to suppress our appetite. Others have suggested that this might trigger a response that leads to nausea.

What can I do about it?

There are a few things you could try to help make you feel better. These include:

  • Taking small, but regular, sips of a cold drink  
  • Ginger or peppermint tea  
  • Eating foods that have ginger in them, like ginger biscuits  
  • Getting some fresh air  
  • Avoiding foods that have a strong smell, or that are fried or greasy
  • Not eating too quickly  
  • Wearing comfortable clothes that fit loosely around your waist and stomach  

As unpleasant as it is, nausea tends to pass. If it becomes worse or doesn’t go away, see your doctor.  


Another common side effect of Ozempic® is diarrhoea—and this is also thought to be linked to how the drug slows the movement of food through the gut. Mostly, diarrhoea from taking Ozempic® isn’t serious and goes away on its own, but in some cases, it can be more severe. Always check with your doctor if you have a side effect that bothers you.  

What can I do about it?

The main advice for dealing with diarrhoea is to drink plenty of fluids, like water and squash, but to avoid caffeine and alcohol. If you feel sick, take small sips.

You could also try eating foods that are lower in fibre, like white bread or rice, which might be gentler on your bowels and help to make your stool firmer.  

It’s also recommended that you stay home and rest up, eating only when you feel able to.  


Ozempic®’s effects on the digestive system can also lead to vomiting. The gut is in constant communication with the brain, giving updates on whether we’re hungry or full and sending alerts when there’s changes in its environment—like if the movement of food through the stomach is slower than normal. These messages from the gut can trigger the signal in the brain that we need to be sick.  

Usually, vomiting isn’t serious and goes away with time.  

What can I do about it?

Being sick can cause you to lose fluids, so staying hydrated is key. Reach for water or squash, taking small sips if you feel unwell. Salty snacks, such as salted nuts, can also help to replace lost salt.  

Only eat when you feel you can. Bland foods like plain white toast can be helpful here as they’re easier to digest.

Heartburn and acid reflux

Heartburn is a burning feeling in the chest that happens due to acid reflux—when stomach acid travels up from the gut and towards the throat. Both can be brought on when it takes longer than normal for the stomach to empty.

Again, people experiencing these effects when taking Ozempic® generally report them to be mild, but they can be more severe in some people. Always check in with your doctor if your side effects are troublesome or don’t go away.  

What can I do about it?

Try eating smaller meals and raising the head of your bed by 10-20cm. This allows your head and chest to lie above your waist when you’re sleeping, which can prevent stomach acid from travelling up to your throat.  

Stress and anxiety can also make heartburn and acid reflux worse. So, finding ways to relax may offer some relief.

Stomach pain

Slowed emptying of the stomach can cause stomach pain—which has been described as “cramping”. Other side effects from Ozempic® like constipation or bloating can also bring on a stomach ache.

However, stomach pain is very common and may be due to something else. If your pain gets worse quickly, doesn’t go away, you have problems swallowing food, it hurts to pee, or you’re experiencing any abnormal bleeding, see your GP right away.  

What can I do about it?

If your stomach pain is due to constipation or bloating, following the advice in those sections may help to relieve it.  

Otherwise, you could try putting a hot water bottle on your tummy, eating foods with ginger in them, and keeping your fluids up so you don’t get dehydrated.


As food moves through the digestive system slower when taking Ozempic®, this can cause production of additional gas—which can make us bloated and uncomfortable. It can also bring on flatulence and belching.  

What can I do about it?

To reduce bloating, you could try:

  • Exercising regularly. This can help improve digestion. In any case, it’s recommended that you work out on the regular while taking Ozempic®  
  • Drinking plenty of water  
  • Eating smaller meals  
  • Chewing with your mouth closed. This can prevent you from swallowing air  
  • Massage your stomach moving right to left, to help release the gas  


Constipation is another common gut issue that can be brought on by Ozempic®. Again, this is thought to be related to the drug’s effect in slowing your stomach emptying. This can delay your bowel movements and lead to constipation.

What can I do about it?

Drink lots of fluids (but not alcohol or fizzy drinks) and eat smaller meals that are low in fat. Usually, eating foods high in fibre is recommended to help with constipation, but if your stomach is emptying at a slower rate then this could slow it down even more. Opt for low-fibre foods instead.

Moving your body more may also help to make you more regular. You should be doing this anyway while using Ozempic®: in scientific research, semaglutide has been shown to be effective for weight loss when people taking it exercised for at least 150 minutes per week and made healthy changes to their diet.


Alongside digestive symptoms, tiredness has also been reported as a side effect of semaglutide. One theory as to why is that because the drug works to reduce our appetite, we eat less food and therefore are taking in less energy. But more scientific research is needed to better understand the link between semaglutide and fatigue.  

Plus, experiencing any of the above side effects can lead to dehydration, which can make you tired.  

What can I do about it?

Taking good care of yourself is the best defence against fatigue. Eating a healthy, balanced diet can help your body get the nutrients it needs to be at its best, while exercising regularly can also boost our energy levels.  

Getting enough sleep plays a key role here, too. Try to develop a relaxing night-time routine to help ease you into sleep, like not looking at your phone after a certain time or reading a book.  

Less common side effects of Ozempic®

These side effects may impact up to one in 100 people who are taking Ozempic®.  

Changes in the way food and drink tastes

Some people report changes in taste when taking Ozempic. We don’t know exactly why this happens, but it might be linked to the change in appetite the drug brings on. This not only makes us want to eat less, but can reduce cravings, too.

In one study of 30 people who were obese, taking semaglutide for 12 weeks was associated with a lower preference for high-fat, energy-dense foods. However, we don’t know if this was because those foods tasted different to the participants.  

Another small study of 15 people who were overweight and had type 2 diabetes found that taking semaglutide didn’t change the taste of food when compared with placebo.  

What can I do about it?

Having a distorted sense of taste can be very frustrating. Usually though, this is temporary, and your taste should return to normal.  

In the meantime, eating a variety of foods with different textures and flavours (like sour, salty, sweet) may improve your ability to taste. You could also try adding strong flavours to your meals, such as via spices or sauces, to help you enjoy the food more.  

Above all, don’t forget to eat a balanced diet and stay hydrated: even if you can’t taste what you’re eating, your body still needs enough essential nutrients and water to work at its best.  

Increased heart rate

Semaglutide can increase heart rate in some people. This is thought to be because the drug stimulates the part of the heart whose job is to generate the electrical signal which makes it beat.  

But this doesn’t appear to increase the risk of heart disease. In fact, semaglutide can reduce the risk of heart problems because of its effects on weight loss.

What can I do about it?

If having an increased heart rate is uncomfortable or is bothering you, seek advice from your doctor.  

Otherwise, breathing exercises, limiting alcohol, reducing stress, exercising regularly, and staying hydrated can all help lower your heart rate.  

Serious side effects of Ozempic

Eye problems (retinopathy)

In some people who are overweight and have type 2 diabetes, taking semaglutide has been associated with retinopathy—a disease where high blood sugar levels damage the back of the eye. If left untreated, it can lead to blindness.  

But for people who are overweight and don’t have type 2 diabetes, some studies report that taking semaglutide doesn’t pose the same risk of retinopathy, so we can’t say for sure whether the drug plays a role in it developing.  

Still, if you notice any changes to your vision while taking Ozempic, see your doctor right away.  

What can I do about it?

See your doctor as soon as you can. If you’re worried about your vision, having regular eye checks may give you peace of mind.  


This is when your pancreas becomes swollen. It may affect up to one in 100 people taking Ozempic.

One of the ways Ozempic works is to stimulate the pancreas to produce insulin after you eat. But in some cases, it can cause the pancreas to become inflamed. Symptoms of pancreatitis are having a sudden and severe pain in the centre of your stomach, feeling or being sick, or having a fever.  

If you have a personal or family history of issues with your pancreas, let your doctor know before you start taking Ozempic.  

What can I do about it?

If you experience severe pain in your stomach and back that doesn’t go away, see a doctor immediately.  

How long after Ozempic injection do side effects start?

There’s no hard-and-fast rule for when side effects start. The drug will start working as soon as you inject it, but if you’re new to Ozempic then your dose will be ramped up over time to help your body get used to it.  

Higher doses of the drug generally have a stronger effect, so it can sometimes take a few weeks for side effects to develop. For example, according to the FDA’s records, it can take 14 days after starting semaglutide for some people to experience diarrhoea and vomiting, and 17.5 days for them to get stomach pain. Some side effects that came on quicker were nausea (4 days) and constipation (10 days).  

Bear in mind that these numbers represent the midpoint out of all the results for each symptom, which means that people experiencing that side effect have a 50:50 chance of getting it earlier or later than that time. Figures like this can give us a rough idea of how people are affected by semaglutide but can’t necessarily tell us what our own experience will be like.  

How long do Ozempic side effects last?

According to clinical studies, side effects are usually mild or moderate and aren’t anything to worry about. And while the drug affects everyone differently, research shows that side effects can last for a few days up to a few weeks. They generally go away on their own, too.  

For example, data from two clinical trials showed that on average, people experienced nausea for 8 days, diarrhoea for 3 days, and vomiting for 2 days.  

Should I take Ozempic?

While it does come with side effects, Ozempic has been shown to be an effective drug in helping people lose weight.  

In one trial, people lost an average of 6% body weight after taking semaglutide for 12 weeks. After taking it for over a year, they lost 14.9% body weight—although the dose of semaglutide used in this trial after the 12-week mark is higher than what’s prescribed when using Ozempic for weight loss, so your results may differ.  

If you have a BMI of 30 or higher (people from certain ethnic backgrounds can have a BMI of 27 or higher) and have at least one other health problem that’s related to your weight, you might benefit from Ozempic.

It may not be recommended for people who have a history of thyroid cancer or issues with their pancreas or kidneys. People who are pregnant or breastfeeding, or who have type 1 diabetes, shouldn’t take Ozempic.  

Due to how the drug is licensed, you need a private prescription to use Ozempic in the UK if you don’t have type 2 diabetes.  

Through our weight loss programme, we can issue you a prescription for weight loss medication like Ozempic that can be renewed every four weeks. You’ll also get weekly advice from a dietician and regular check-ins, so that we can support you to reach your health goals. Our programme is designed to help you lose weight gradually and teach you habits to keep it off for good.  

You can get started right now: check your eligibility to join by filling out this short questionnaire. It takes less than five minutes.