Wegovy Pill Side Effects: What to Expect and How to Manage Them

Nausea, vomiting, constipation, diarrhoea, and stomach pain. So what are the Wegovy pill side effects, and why are they mostly gut-related? Because semaglutide is a GLP-1 receptor agonist.

It mimics a hormone your gut releases after a meal, slowing stomach emptying and reducing appetite and cravings. Your digestive system has to catch up to the changes.

Semaglutide is also used in type 2 diabetes, so we have years of data on how it behaves. Side effects of the new Wegovy pill formulations mostly reflect what we see from the injection and diabetes tablets.

Nearly three-quarters of the people taking Wegovy reported gut side effects in the OASIS 4 trial. This trial was a 64-week study of 307 adults. On placebo (empty pills), that number dropped to just over 40%. Most people reported their side effects of Wegovy as mild to moderate.

When do Wegovy pill side effects start? Usually, feeling sick on Wegovy pills is the most commonly reported side effect. It starts within the first few days of treatment or moving to a higher dose. Typical duration: around 13 days. Nausea on the Wegovy pill is often one of the first side effects to ease off.

Not all oral semaglutide side effects follow the same pattern. Vomiting is more short-term, lasting around 2 days in the trial. It tends to hit sharply, then pass.

Constipation on oral Wegovy behaves differently to nausea. It builds gradually and can persist for longer, affecting around 1 in 5 people. Some people find that the Wegovy pill and constipation become a persistent issue. If that happens, you may need medication such as a laxative to help keep you regular – only for short term use.

Heartburn on the Wegovy pill is more predictable. If you eat a large or fatty meal, semaglutide holds that food in your stomach longer than usual. The acid builds up with nowhere to go.

On Wegovy tablets, digestive problems and heartburn affect about 1 in 10 people. Less common than nausea, with the advantage that you have more control over it through what and when you eat.

The OASIS 4 trial found a link between the Wegovy pill and blood pressure. People who lost 15% or more body weight saw blood pressure come down by around 10 points. In those who lost less, the drop was closer to 4.

Headaches affected between 11% and 15% of participants, mostly early on in their treatment journey. Dizziness and fatigue have also been reported. Likely causes include eating less, dehydration, or shifts in blood sugar levels.

Some Wegovy pill weight loss side effects come from the weight loss rather than the drug. Hair loss on the Wegovy pill has been reported. This is a possible effect with all GLP-1 medicines, and a 2025 FAERS study found no clear link to semaglutide itself.

The trigger is more likely the weight loss itself. Rapid loss puts the body under stress, and hair follicles go into a resting phase. They shed a few months later but typically grow back once your weight stabilises.

Who is more likely to get side effects?

An existing gut condition makes the most difference. If you have gastroparesis, where the stomach empties too slowly, gut side effects can be more serious or more severe.¹¹ Semaglutide is not recommended where gastroparesis is severe.

Yes, for most people. The worst is over within the first 12 weeks, once the body adjusts to the 25mg maintenance dose.

The Wegovy pill dosage schedule starts at 1.5mg, gradually increasing to 25mg over 12 weeks. You move up every 30 days. Wegovy 1.5 mg pill side effects are usually milder. They tend to peak as you increase your doses.

How long do Wegovy pill side effects last? For most people, they are at their worst during the dose-escalation period and improve once they reach the maintenance dose.

When do Wegovy pill side effects ease? Typically, once you reach 25mg and your body adjusts to the medication. But not everyone follows this pattern.

Some people take longer to settle. If a dose increase is difficult, we may hold you at the current level. Faster escalation is a common reason nausea becomes harder to manage.

In the trial, 6.9% stopped due to side effects versus 5.9% on placebo. Trials involve regular monitoring, so real-world dropout may differ. Data on the long-term side effects of Wegovy pill treatment is currently limited.

Oral semaglutide has been used for diabetes at lower doses for several years. But the higher 25mg weight management dose is newer, and researchers are still studying long-term side effects.

Generally speaking, no. Semaglutide is semaglutide. Will the Wegovy pill have less side effects than the once-a-week injectable version? Not necessarily.

The Wegovy pill vs the injection side effect profile is broadly the same.

You do get slightly more vomiting with the pill (30.9% versus 24.8%). Wegovy injection side effects include redness, bruising, and swelling at injection sites. You avoid all of that with the tablet.

Sensitive skin on the Wegovy pill

The OASIS 1 trial tested a higher 50mg oral dose. Certain skin sensations, called dysaesthesia, appeared that were almost never reported with the injection. The numbers: tingling (paresthesia) at 2.7%, sensitive skin at 2.7%, skin pain at 2.4%.

Around 5% of people on Wegovy tablets experienced some form of skin sensitivity.

For many people who experience it, sensitive skin on Wegovy is mild and settles without treatment. If it persists, we can guide you on measures that may help.

Managing side effects on Wegovy starts with the dosing rules. You take the tablet on an empty stomach, first thing in the morning, with plain water only (up to 120ml).

Then, you wait. At least 30 minutes before eating, drinking anything else, or taking other tablets. Skip or rush this, and the drug will not absorb consistently.

Most side effects from the Wegovy pill treatment respond to practical adjustments.

Nausea

For nausea on the Wegovy pill, think smaller and more often. Your stomach is emptying more slowly than usual, so three large meals will hit harder. Eat slowly. Do not lie down straight after meals.

Fatty or spicy food tends to worsen symptoms during dose escalation. You may find ginger-based drinks and peppermint tea helpful, although the evidence behind them is limited.

Constipation

For constipation on oral Wegovy, hydration comes first. Drink plenty of water throughout the day, and more during dose escalation. Then build up your fibre: fruit, vegetables, wholegrains, beans. If dietary changes don’t resolve the issue in two weeks, speak to us. Contact your GP if you have not had a bowel movement in 7 days, or if you experience any of the following:

• Severe or worsening abdominal pain
• Persistent vomiting or marked bloating
• Inability to pass gas
• Blood in your stool

These symptoms require prompt medical review to rule out serious complications.

Vomiting and Diarrhoea

When it comes to vomiting and diarrhoea on Wegovy tablets, fluid intake is the priority. Dehydration is a real risk with GLP-1 medicines and can affect your kidneys. Inability to keep fluids down requires medical advice.

If side effects remain difficult, we can extend the time at your current dose to give you longer to adjust.

What if you miss a dose?

Skip the missed dose and take your normal dose the next day.¹⁰ If you have missed several days in a row, get in touch before you take the next one.

Yes. Semaglutide slows how quickly your stomach empties, which can change how other tablets you swallow are absorbed.¹¹ Tell your prescriber about everything you take, including anything you buy over the counter.

Levothyroxine for an underactive thyroid is one to flag. Your thyroid levels may need checking while you take the two together.¹¹

Can the Wegovy pill cause low blood sugar?

Yes, if you also take insulin or a sulfonylurea for type 2 diabetes. Those combinations raise the risk of low blood sugar (hypoglycaemia).¹¹ Signs include a cold sweat, cool pale skin, headache, a fast heartbeat and feeling very hungry.¹⁰

Several serious side effects of the Wegovy pill need medical attention. They are uncommon but should not be ignored.

Pancreatitis

Severe stomach pain spreading to the back, sometimes with vomiting. Reported with all GLP-1 medicines. The UK regulator (MHRA) strengthened its warnings in January 2026 after rare reports of severe or fatal cases. Stop the drug straight away and seek urgent medical advice if suspected. Dial 999 or go to A&E. Do not wait to see if it passes.

Gallbladder disease

Around 2.5% of people on the Wegovy tablet developed gallstones, versus 1% on placebo. Rapid weight loss carries an increased risk of gallstones in its own right, so the medication may not be the only cause. Contact your GP or our clinical team for assessment.

Thyroid C-cell tumours

Semaglutide caused thyroid tumours in rodent studies at higher doses. Whether this applies to humans is unknown. Do not take the Wegovy pill if you or a family member has had medullary thyroid carcinoma (MTC) or multiple endocrine neoplasia syndrome type 2 (MEN).

Kidney injury

Not from the drug directly, but from dehydration caused by vomiting or diarrhoea. This is why staying hydrated is not just comfort advice, but a safety issue.

NAION (eye damage)

In February 2026, the Medicines and Healthcare products Regulatory Agency (MHRA) issued a safety warning linking semaglutide to a very rare eye condition called non-arteritic anterior ischaemic optic neuropathy (NAION). This typically causes sudden, painless vision loss or rapidly worsening eyesight in one eye. If you notice any sudden change in your vision while taking the Wegovy pill, go to eye casualty or A&E urgently.

Surgery and anaesthesia

Tell your healthcare team, including the anaesthetist, before any procedure under general anaesthetic or deep sedation.¹² These medicines slow stomach emptying, so food and drink can still be there despite fasting beforehand.¹² Keep taking your prescribed medicine as usual unless your doctor tells you otherwise.¹²

Suicidal thoughts.

If you or someone close to you notices changes in mood or thinking, contact your GP straight away. The Samaritans are available on 116 123 at any time. You can also ask for the CRISIS team at A&E.

Individual risk depends on your medical history. In OASIS 4, 3.9% of participants on semaglutide experienced serious side effects, compared with 8.8% on placebo. The lower number likely reflects the health benefits of losing weight, not that the drug itself is risk-free. That is why knowing who should not take the Wegovy pill matters.

You should not wait to see if certain symptoms pass. Some need urgent attention.

Dial 999 or go to A&E if:

• You develop severe stomach pain that spreads to your back
• You notice swelling in your face, lips, tongue or throat, or you are struggling to breathe

Ring NHS 111 if:

• You cannot stop vomiting and cannot keep fluids down

See your GP urgently if:

• You notice yellowing of your skin or the whites of your eyes
• You experience sudden vision loss or rapid blurring in one or both eyes
• You are experiencing an increase in anxiety or a worsening of your mood
• You feel dizzy, shaky, or confused, especially if you are also taking medication for diabetes. This could indicate low blood sugar levels.

You do not need a doctor for most Wegovy pill side effects. Nausea, mild constipation and bloating are adjustment symptoms. But the ones listed above are different.

Does the Wegovy pill have side effects?

Yes. In clinical trials, nearly three in four participants reported side effects. Most were gut-related.

You are likely to notice them most during the first 12 weeks, while your body is still adjusting. After that, most people find things settle.

Do Wegovy side effects get better over time?

Mostly. You will probably find that symptoms peak when starting Wegovy and around dose increases, then ease as your body adjusts. Some side effects, like constipation, can take longer to settle.

Does the Wegovy pill have more side effects than the injection?

Overall, Wegovy weight loss pill side effects are similar. The Wegovy pill form side effects that differ are mainly skin-related.

How do you manage side effects on Wegovy?

The dosing rules come first. Take the tablet on an empty stomach with water, then wait 30 minutes before eating.

For nausea, smaller and more frequent meals make a real difference.

For constipation, increase fibre and drink plenty of water. If things are not improving, our clinical team can adjust the schedule.

Can you drive on the Wegovy pill?

Yes. Dizziness shows up mainly while your dose is going up.¹¹ Do not drive or use machines until you feel better.¹⁰

Can you take the Wegovy pill if you are pregnant or breastfeeding?

No. The leaflet says not to use it while breast-feeding, because the medicine passes into breast milk and its effect on a baby is not known.¹⁰ If you could become pregnant, use contraception, and stop at least two months before trying for a baby.

• How you take the Wegovy pill matters. Dosing rules, meal choices, and staying at each dose level for the full 30 days all influence tolerability.
• What the trials call “mild to moderate” does not always feel that way when you are living through it. Your experience may be very different from someone else’s.
• Serious side effects are rare. They still need urgent attention. Data on long-term side effects is limited, as the 25mg dose is relatively new. The “when to see a doctor” section above lists what to watch for.