The most common Wegovy pill side effects are digestive: nausea, vomiting, diarrhoea, constipation, indigestion and stomach pain, plus headache and tiredness. In the 64-week OASIS 4 trial, nausea affected 46.6% of people on the tablet (18.6% on placebo) and vomiting 30.9% (5.9% on placebo). Most were mild to moderate, short-lived and commonest while the dose was being stepped up; serious problems such as acute pancreatitis are uncommon but need urgent help.
Unless noted, figures come from the UK leaflet and Summary of Product Characteristics (SmPC) for the tablet the MHRA approved on 11 June 2026, both revised June 2026 and current as of September 2026. This is information only, not medical advice: the Wegovy pill (oral semaglutide) is prescription-only, and a prescriber decides whether it suits you.
What are the most common Wegovy pill side effects?
The UK patient leaflet lists as very common (more than 1 in 10): headache, nausea, vomiting, diarrhoea, constipation, stomach pain, feeling weak or tired, and an upset stomach or indigestion. Its common list (up to 1 in 10) adds dizziness, burping, wind, bloating, an inflamed stomach (gastritis), reflux or heartburn, gallstones, hair loss, taste changes, a change in skin sensation and, in people with diabetes, low blood sugar.
| Side effect | Wegovy tablet | Placebo |
|---|---|---|
| Nausea | 46.6% | 18.6% |
| Vomiting | 30.9% | 5.9% |
| Constipation | 20.1% | 9.8% |
| Indigestion | 18.1% | 8.8% |
| Diarrhoea | 17.6% | 8.8% |
The SmPC says OASIS 4 frequencies were similar to the injection's STEP trials except for indigestion (dyspepsia), which fell into a higher frequency category (see pill vs injection).
Why are side effects worst in the first few months?
Because the dose is climbing: the SmPC flags gut effects, headache, dizziness and fatigue as mainly seen during dose escalation. Treatment starts at 1.5 mg once daily, rising through 4 mg and 9 mg to the 25 mg maintenance dose, with at least a month at each step; the US label says to follow it to reduce the risk of gut side effects. If needed, the dose can stay at the previous level (see our dosage guide).
The SmPC also lists slower stomach emptying as a side effect (see how the Wegovy pill works). The leaflet says some people feel dizzy, mainly in the first three months; if so, do not drive or use machines until you feel better.
How long do Wegovy pill side effects last?
Usually not long. In OASIS 4, nausea, vomiting and diarrhoea were mostly mild to moderate and short-lived; constipation was similar in severity but lasted longer.
Gut side effects led 3.4% of people on the tablet to stop permanently; the US label (revised June 2026) puts stopping for any adverse reaction at about 7%, against 5.9% on placebo. Across the 71-week study, ClinicalTrials.gov records serious adverse events in 8 of 204 people on the tablet and 9 of 102 on placebo.
Can the Wegovy pill cause hair loss or skin tingling?
Yes. In OASIS 4, hair loss affected 6.4% on the tablet and 2.0% on placebo; all cases were mild or moderate and half had recovered by the end of the trial. The UK and EU product information add that hair loss was reported more often with greater weight loss (20% or more).
Altered skin sensation — sensitive skin, pins and needles, a burning feeling or pain from light touch — affected 4.9% on the tablet and nobody on placebo. It was mild to moderate, and most people recovered while continuing treatment.
Which serious side effects need urgent help?
The leaflet flags these as urgent:
- Severe stomach pain that does not go away, sometimes felt in the back: possible acute pancreatitis, rated uncommon (up to 1 in 100). Stop the medicine and seek urgent medical help.
- Breathing problems or swelling of the face, lips, tongue or throat: a possible severe allergic reaction, rated rare (up to 1 in 1,000). The NHS says to call 999 for suspected anaphylaxis.
- Sudden loss of vision or rapidly worsening eyesight: possibly NAION, an eye condition rated very rare (up to 1 in 10,000). Contact a doctor urgently.
OASIS 4 recorded no acute pancreatitis on the tablet (1.0% on placebo), but the SmPC warns of post-marketing reports of necrotising and fatal cases with GLP-1 medicines. For other possible serious side effects, the NHS advises calling 111.
Also worth raising with your prescriber
- Gallstones: 2.5% on the tablet versus 1% on placebo in OASIS 4.
- Kidney or bladder stones: uncommon; watch for back or lower abdominal pain, difficulty passing urine or changed urine colour.
- Dehydration: vomiting and diarrhoea can, in rare cases, worsen kidney function, so drink enough fluids.
- Diabetes: low blood sugar is more likely with a sulfonylurea or insulin, and diabetic eye disease can temporarily worsen, so report any change in vision.
- Bowel obstruction: a severe form of constipation with stomach ache, bloating or vomiting; frequency not known.
- Surgery or sedation: tell the team: food stays in the stomach longer, and inhaling stomach contents under general anaesthesia or deep sedation has been reported with GLP-1 medicines.
What about the thyroid warning?
The US label carries a boxed warning about thyroid C-cell tumours, based on rodent studies; it says it is unknown whether semaglutide causes them in humans and rules out use with a personal or family history of medullary thyroid carcinoma or MEN 2. The UK SmPC considers the rodent finding's relevance to humans low but not completely excluded, and lists allergy to the ingredients as its only contraindication. If thyroid cancer runs in your family, tell your prescriber.
What about pregnancy and other medicines?
Do not use the Wegovy pill in pregnancy or while breastfeeding; the leaflet says to use contraception and stop at least 2 months before trying for a baby. The MHRA's advice to add a barrier method alongside the contraceptive pill is given for Mounjaro (tirzepatide), not semaglutide. Mention levothyroxine or warfarin to your prescriber, as both may need monitoring.
How can you make side effects easier to live with?
- Stick to the schedule and the empty-stomach rule. Never take two tablets for a higher dose; skip a missed dose and take your usual one the next day.
- Avoid alcohol: the NHS says it is best not to drink, as it can increase nausea and vomiting.
- Ask a pharmacist or doctor about side effects that bother you or do not go away, and do not stop without talking to your prescriber.
How do I report a Wegovy pill side effect?
The tablet carries a black triangle (▼): it is under additional monitoring. Report any suspected side effect, even one not in the leaflet, through the MHRA Yellow Card scheme website or app. The MHRA also wants reports of suspected fakes and warns against buying GLP-1 medicines from unregulated sellers such as beauty salons or social media. See also our side effects overview and FAQ.
Frequently asked questions
Do Wegovy pill side effects go away?
Usually. The UK leaflet says the very common ones usually go away over time, and in OASIS 4 most nausea, vomiting and diarrhoea was mild to moderate and short-lived. Constipation tended to last longer.
Is the Wegovy pill harder to tolerate than the injection?
Not clearly. The UK SmPC describes the tablet's OASIS 4 safety profile as consistent with the injection's STEP trials, with similar frequencies except for indigestion. They were separate trials, so differences between them should not be over-read.
Can the Wegovy pill cause hair loss?
Yes. In OASIS 4, 6.4% of people on the tablet reported hair loss versus 2.0% on placebo. All cases were mild or moderate, and half had recovered by the end of the trial.
What stomach pain should I worry about on the Wegovy pill?
Severe, persistent stomach pain, sometimes felt in the back, can be a sign of acute pancreatitis: stop the medicine and seek urgent medical help. Stomach pain in general is very common while the dose is rising; if you are unsure, call NHS 111.
How do I report a side effect of the Wegovy pill?
Use the MHRA Yellow Card scheme website or app, and tell your doctor, pharmacist or nurse. You can report any suspected side effect, even one not in the leaflet.