Curious about trying Wegovy? You’ve probably heard that this prescription weight loss medicine works very well to support weight loss. Some people lose up to 15% of their starting weight after taking it for over a year. And we’ve written an article about the results you might see week on week with Wegovy.
But you also might be worried about its side effects. We hear you—there’s plenty of scary stories out there in the media.
Wegovy, which contains the active ingredient semaglutide, does come with side effects, but we want to reassure you that for most people, they’re nothing to worry about and will clear up on their own. The benefits of the medicine usually far outweigh their impact.
Still, it’s important that you’re clued up on what these symptoms look like and how you can deal with them.
Most common side effects on Wegovy
So, what sort of side effects might you expect when taking Wegovy? It’s true that they’re pretty common, affecting more than one in ten people using the medicine.
But, again, most of the time they’re mild and fairly easy to manage.
Nausea
This is one of the most common side effects that comes up in scientific research. And Wegovy’s effect on the gut is thought to be responsible.
Wegovy works by suppressing your appetite. One way it does this is by slowing the rate of digestion, so you feel fuller for longer. Nausea could be a knock-on effect of that.
Vomiting
Being sick is your body’s way of removing a threat, like a bacteria or toxin, from your system. Your gut is constantly talking to your brain, letting it know if anything changes in its environment and alerting it to any potential issues.
We don’t know exactly why Wegovy can cause people to be sick, but it’s probably to do with slowed digestion (meaning that food moves slower through your system). Sometimes, this can upset your stomach and signal to the brain that you need to throw up.
Diarrhoea
There’s a few possible explanations for how Wegovy could bring on diarrhoea. The first is its effect in delaying digestion. But because research has shown that Wegovy can influence how the gut absorbs fat and sugar, there’s a theory that this plays a role, too.
Constipation
Another complication of slowed digestion is delayed bowel movements, which could lead to constipation. In clinical trials, just over one in five people taking the highest dose of Wegovy had constipation, but symptoms were manageable and cleared up on their own.
Less common side effects on Wegovy
Low blood sugar (hypoglycaemia)
Aside from its effect on the gut, another way that Wegovy makes you feel full is by telling the pancreas to produce more insulin when you eat. This signals to the brain that you’ve had enough.
Insulin’s job is to take sugar from the blood and shuttle it around the body, so it can be used as energy. It’s uncommon, but Wegovy can sometimes make your blood sugar dip too low—even in people without type 2 diabetes.
Changes in how food and drink tastes
Yes, really! Some people have said that their tastes have changed since starting Wegovy.
There is some science behind this. Research says that changes to our metabolic health (like losing weight) can affect our sense of taste. For example, sweet foods might taste less intense to people who weigh more, which could then lead them to eat more in order to satisfy a craving.
On top of that, studies suggest that Wegovy can directly interact with our taste buds, too. People taking it have reported reduced cravings for sweet, savoury, and salty foods.
More serious side effects of Wegovy
There are some more serious symptoms that could potentially linger on. But before we dive in, we do want to reiterate that Wegovy is considered safe for most people, and that the below side effects are rare.
Most people taking Wegovy won’t experience these. But if you do encounter these serious side effects, you should seek help from a healthcare provider right away. You can call the NHS on 111 for advice on what to do or head to A&E.
Severe pain in your stomach that doesn’t go away
This can be a sign of pancreatitis. Sometimes, the pain will move to your back. Other signs of pancreatitis are having a high temperature (38C or more), nausea, and being sick.
Intense stomach pain can also be due to kidney or bladder stones. In these instances, you might have difficulty peeing or notice a change in the colour of your urine as well.
Allergic reactions
If you have trouble breathing or swallowing, or any swelling of your face, lips, tongue, and/or throat, it might be due to an allergic reaction. You’ll need to get help for this straight away.
Pancreatitis
This is when your pancreas becomes inflamed.
Remember when we explained that Wegovy acts on the pancreas? In some cases, this may bring on pancreatitis. Though in research, it happened to less than 1% of people without diabetes.
You’ll have to go to the hospital to get treatment for pancreatitis. Milder cases can clear up within about a week, though recovery can take longer if it’s more serious.
Gallbladder disease
There’s also been some instances of gallbladder disease, like gallstones and an inflamed gallbladder. Again, it’s rare—in clinical trials, 1.6% of people on Wegovy reported the former and 0.6% had the latter.
Do Wegovy side effects increase with dosage?
Generally speaking—yes, you’re more likely to experience side effects as you take stronger doses of Wegovy. But if you follow the dosing schedule, you’ll minimise your risk of getting them.
By starting on the lowest dose, 0.25mg, you’re allowing your body to get used to the medicine so it can handle stronger doses later on. Then, if you’re tolerating the medicine okay, you’ll gradually move up to higher strengths. FYI: it’s completely fine to stay on lower doses, Wegovy will still work.
We’ve covered what you can expect when you take Wegovy in more detail here.
How to ease Wegovy side effects
The good news is that mostly, Wegovy side effects are pretty easy to deal with.
Taking regular sips of a cold drink, or having a mug of ginger or peppermint tea, could help with nausea. For diarrhoea and vomiting, try resting and drinking plenty of fluids—eating only when you feel able to. Try and avoid any potential trigger foods, such as spicy, rich or fatty foods. And cut down on alcohol, caffeine and fizzy drinks.
Eating smaller meals that are lower in fat can ease constipation. High-fibre foods like fruit and vegetables, oats and pulses can also help.
For any symptoms that hang around or aren’t getting better, check in with your doctor.
Who should not use Wegovy?
Whether Wegovy is right for you is ultimately a call for your prescriber. It’s meant for people with a BMI of 30 or more, or who have a BMI of at least 27 plus another health condition related to their weight.
You shouldn’t use Wegovy if you’re pregnant or breastfeeding, or have type 1 diabetes. It’s important to discuss all of your medical conditions and current medications with your prescriber to determine your suitability for treatment.
When do side effects start with Wegovy?
Everyone’s different, so there’s no telling when (and if!) you’ll get side effects from Wegovy.
The medicine will have an effect as soon as you take it, so it’s possible that you’d get symptoms right away. Or they might pop up as you move up to a higher dose—in clinical trials, this is when side effects tend to come on.
How long do Wegovy side effects last?
Usually, not longer than a few days. Again, this can vary from person to person.
But to give you an idea: in studies, nausea lasted for an average of eight days. Diarrhoea cleared after three days, while vomiting passed after two. Constipation tended to hang around a little longer—47 days on average.
The vast majority of these symptoms (over 99%) weren’t serious.
Is Wegovy right for you?
It’s so important to make an informed decision when trying a new medicine. Yes, like any medicine, Wegovy comes with side effects—but it’s considered safe for most people. And it works very well for weight loss.
If you are interested in Wegovy, we’re here to help make your journey as smooth as possible. It’s a long-term commitment to reaching your health goals (Wegovy should be taken for at least a year, alongside healthy lifestyle changes) and we know you can do it.
But you don’t have to do it alone. As part of our weight loss programme, you’ll get one-to-one support from our team of expert coaches, weekly medication, and an app to keep tabs on your progress. You can find out if you’re eligible right now by filling out this short form.
¹“Acute Pancreatitis: Causes.” NHS
, www.nhs.uk/conditions/acute-pancreatitis/causes/. Accessed 11 Dec. 2024.
²Colhoun, Helen M., et al. “Long-Term Kidney Outcomes of Semaglutide in Obesity and Cardiovascular Disease in the SELECT Trial.” Nature Medicine, vol. 30, no. 7, 2024, pp. 2058–2066. doi:10.1038/s41591-024-03015-5.
³Drucker, Daniel J. “The Cardiovascular Biology of Glucagon-like Peptide-1.” Cell Metabolism, vol. 24, no. 1, 2016, pp. 15–20. doi:10.1016/j.cmet.2016.06.009.
⁴“Diarrhoea and Vomiting.” NHS, www.nhs.uk/conditions/diarrhoea-and-vomiting. Accessed 11 Dec. 2024.
⁵“Feeling Sick (Nausea).” NHS, www.nhs.uk/conditions/diarrhoea-and-vomiting/. Accessed 11 Dec. 2024.
⁶Jensterle, Mojca, et al. “Does Intervention with GLP-1 Receptor Agonist Semaglutide Modulate Perception of Sweet Taste in Women with Obesity: Study Protocol of a Randomised, Single-Blinded, Placebo-Controlled Clinical Trial.” Trials, vol. 22, 2021, p. 464. https://pmc.ncbi.nlm.nih.gov/articles/PMC8287101/.
⁷Lincoff, A. Michael, et al. “Semaglutide and Cardiovascular Outcomes in Obesity Without Diabetes.” The New England Journal of Medicine, vol. 389, no. 24, 2023, pp. 2221–2232. www.nejm.org/doi/full/10.1056/NEJMoa2307563.
⁸Shu, Yamin, et al. “Gastrointestinal Adverse Events Associated with Semaglutide: A Pharmacovigilance Study Based on FDA Adverse Event Reporting System.” Frontiers in Public Health, vol. 10, 2022, article 996179. pmc.ncbi.nlm.nih.gov/articles/PMC9631444/.
⁹Singh, Prashant, et al. “Nausea: A Review of Pathophysiology and Therapeutics.” Therapeutic Advances in Gastroenterology, vol. 9, no. 1, 2016, pp. 98–112. pmc.ncbi.nlm.nih.gov/articles/PMC4699282/.
¹⁰Smits, Mark M., and Daniël H. Van Raalte. “Safety of Semaglutide.” Frontiers in Endocrinology, vol. 12, 2021, article 645563. pmc.ncbi.nlm.nih.gov/articles/PMC8294388/.
¹¹Sodhi, Mohit, et al. “Risk of Gastrointestinal Adverse Events Associated with Glucagon-Like Peptide-1 Receptor Agonists for Weight Loss.” JAMA, vol. 330, no. 18, 2023, pp. 1795–1797. jamanetwork.com/journals/jama/fullarticle/2810542.
¹²Waseem, Shamaila, et al. “Gastroparesis: Current Diagnostic Challenges and Management Considerations.” World Journal of Gastroenterology, vol. 15, no. 1, 2009, pp. 25–37. pmc.ncbi.nlm.nih.gov/articles/PMC2653292/.
¹³Weir, Sara-Bethany S., and Hossein Akhondi. “Bland Diet.” StatPearls, StatPearls Publishing, 2023. www.ncbi.nlm.nih.gov/books/NBK538142/. Accessed 11 Dec. 2024.
¹⁴“Wegovy: Full Prescribing Information.” Food and Drug Administration, www.accessdata.fda.gov/drugsatfda_docs/label/2023/215256s007lbl.pdf. Accessed 11 Dec. 2024.
¹⁵“Wegovy. Package Leaflet: Information for the Patient.” Electronic Medicines Compendium, www.medicines.org.uk/emc/files/pil.13800.pdf. Accessed 11 Dec. 2024.
¹⁶Wharton, Sean, et al. “Gastrointestinal Tolerability of Once-Weekly Semaglutide 2.4 mg in Adults with Overweight and Obesity, and the Relationship Between Gastrointestinal Adverse Events and Weight Loss.” Diabetes, Obesity and Metabolism, vol. 24, no. 1, 2021, pp. 94–105. pmc.ncbi.nlm.nih.gov/articles/PMC9293236/.
¹⁷Wharton, Sean, et al. “Two-Year Effect of Semaglutide 2.4 mg on Control of Eating in Adults with Overweight/Obesity: STEP 5.” Obesity, vol. 31, no. 3, 2023, pp. 703–715. doi:10.1002/oby.23673.
¹⁸Wilding, John P.H., et al. “Once-Weekly Semaglutide in Adults with Overweight or Obesity.” The New England Journal of Medicine, vol. 384, no. 11, 2021, pp. 989–1002. www.nejm.org/doi/full/10.1056/NEJMoa2032183.
