Most people who take the Wegovy pill get side effects at some point — usually gut symptoms, usually during dose increases, and usually manageable. A smaller number run into something that needs to be reviewed. This is the pharmacist's guide to what to expect, what helps, and when to stop and seek advice.

The common ones (gut symptoms)

  • Nausea
  • Diarrhoea
  • Constipation
  • Vomiting
  • Decreased appetite (which is partly the point, but can feel like a side effect)

These are mostly seen when you first start and each time you step up a dose. For most people they ease within a week or two as the body adjusts. They're the reason the dose is titrated slowly rather than jumping straight to 25mg.

How to manage them

  • Take the tablet correctly — on an empty stomach with a sip of plain water, then wait at least 30 minutes.
  • Eat smaller, more frequent meals instead of large ones.
  • Avoid fatty, fried and very sweet foods; they're the usual triggers for nausea and reflux.
  • Stay well hydrated — sip fluids through the day rather than drinking large amounts at once.
  • Bland foods (toast, crackers, plain rice) and ginger (tea, biscuits) genuinely help nausea for many people.
  • Don't rush the titration. If a step is hard, staying at the current dose a little longer is usually better than pushing up.

Less common but important

These are rarer but worth knowing about because they change what you should do:

  • Acute pancreatitis — severe, persistent abdominal pain that often radiates to the back, usually with vomiting. Stop the medicine and seek urgent medical review.
  • Gallbladder disease — sudden pain in the right upper abdomen, sometimes with nausea. Seek assessment.
  • Dehydration and kidney injury — from prolonged vomiting or diarrhoea. Keep fluids up; if you can't, get reviewed.
  • Hypoglycaemia — mainly a risk if you're also taking insulin or a sulfonylurea for diabetes. If that's you, your prescriber will discuss recognising and treating low blood sugar.
  • NAION (a rare eye condition) — sudden or partial loss of vision needs urgent eye assessment.
  • Thyroid — report any new lump in the neck, hoarseness or trouble swallowing.

When oral semaglutide isn't suitable

  • Personal or family history of medullary thyroid cancer, or multiple endocrine neoplasia type 2 (MEN2).
  • Previous pancreatitis.
  • Pregnancy, breastfeeding, or planning pregnancy.
  • Known allergy to semaglutide or any of the excipients.

Frequently asked questions

How long does the nausea last? Usually a few days to a couple of weeks after starting or stepping up. If it's not settling, tell your pharmacist before the next increase.

How do I reduce side effects? Take the tablet correctly, eat smaller and blander meals, hydrate, and don't rush the titration.

Is oral semaglutide safe? For eligible adults it has a well-characterised safety profile from OASIS-1 and OASIS-4. Like any GLP-1 medicine it needs pharmacist-led monitoring.

When should I stop and seek help? Severe or persistent vomiting, severe abdominal pain, sudden vision changes, or a new neck lump — stop the medicine and get reviewed the same day.

When to see your pharmacist or doctor

  • Severe or persistent vomiting, or signs of dehydration
  • Severe abdominal pain, especially if it radiates to the back (possible pancreatitis)
  • Sudden or partial vision changes
  • A new lump in the neck, persistent hoarseness or trouble swallowing
  • Before stepping up to the next dose if side effects aren't settling

References

  1. Wharton S, et al. Oral semaglutide 25 mg in adults with overweight or obesity (OASIS-4). N Engl J Med 2025.
  2. Knop FK, et al. Oral semaglutide 50 mg for weight loss (OASIS-1). Lancet 2023.
  3. MHRA. Product information for oral semaglutide (Wegovy tablets), 2026.

Reviewed by Jimah Alsaai MPharm, GPhC 2232652, Superintendent Pharmacist, Solira.