Wegovy side effects: what’s common, what’s serious, and how long they last.
Your week, cooked
7 meals · 28g protein on average · food, not medicine
Delivered chilled across Sydney, Melbourne and Brisbane metro.
First box $79.65 with PLAN20 (new customers, added for you at checkout). Then $99.65 a week for 7 meals with delivery — skip, pause or cancel before any weekly cutoff. Make it 8 meals and delivery is free ($103.60 all in).
4.6 · 438 verified ratings · Skip or cancel anytime · SYD · MEL · BNE
Wegovy (semaglutide) is a weekly injection registered in Australia for weight management. Most people who take it get at least one stomach-related side effect, usually mild and short-lived. This page sets out what the official Australian documents list, how often each effect happened in trials, how long they tend to last, and the warning signs that need a doctor straight away.
The most common Wegovy side effects are nausea, diarrhoea, vomiting, constipation and stomach pain. In the trials behind the Australian Product Information, nausea affected 38.3% of people on Wegovy compared with 14.0% on placebo. Most stomach side effects were short: the median episode of nausea lasted 8 days. Serious effects such as pancreatitis, gallbladder problems and bowel obstruction are uncommon or rare but need urgent care.
- Stomach and bowel effects are the most common: nausea, diarrhoea, vomiting, constipation and stomach pain.
- Most episodes were brief in trials. Median length: nausea 8 days, diarrhoea 3 days, vomiting 2 days, constipation 47 days.
- About 1 in 23 people in the STEP 1 to 3 trials stopped Wegovy because of stomach side effects (4.3%).
- Severe ongoing stomach pain, sudden vision loss or signs of an allergic reaction need a doctor or emergency department straight away.
- Drinking enough fluid matters: the CMI warns that vomiting and diarrhoea can cause dehydration.
- Registered: Wegovy is TGA-registered for weight management in adults (BMI 30 or more, or 27 or more with a weight-related condition) and adolescents aged 12 and over, plus other uses. Wegovy CMI.
- Documents checked: Wegovy FlexTouch CMI (prepared July 2026) and the Australian Product Information (revised 3 November 2026).
- PBS: Wegovy is not PBS-listed. The PBAC considered a revised submission at its 4 to 6 November 2026 meeting; outcomes are scheduled to be published around 18 December 2026. PBS medicine status; PBS timetable.
- Tablets: Wegovy tablets were added to the ARTG on 3 November 2026 and had not been released to pharmacies when we checked. This page covers the weekly injection. ARTG entry.
- Higher dose: a 7.2 mg weekly dose is now in the Australian documents for some adults. Hair loss and skin-sensation changes were more common at that dose.
What are the most common side effects of Wegovy?
The most common side effects of Wegovy are nausea, diarrhoea, vomiting, constipation and stomach pain, followed by headache and tiredness. The Consumer Medicine Information (CMI) lists these as “very common”, meaning they may affect more than 1 in 10 people. The table shows how often each happened in the weight-management trials summarised in the Australian Product Information (PI).
| Side effect | Wegovy 2.4 mg | Placebo (dummy injection) |
|---|---|---|
| Nausea | 38.3% | 14.0% |
| Diarrhoea | 26.8% | 14.3% |
| Constipation | 21.8% | 10.2% |
| Vomiting | 21.8% | 5.7% |
| Stomach (abdominal) pain | 18.1% | 9.0% |
| Headache | 12.8% | 8.7% |
| Tiredness (fatigue) | 9.6% | 4.7% |
| Hair loss | 2.5% | 1.0% |
| Gallstones | 1.6% | 1.1% |
Source: Wegovy Australian PI, Table 3 (placebo-controlled weight-management trials, 2,650 people on Wegovy and 1,529 on placebo). Placebo rates show how often these symptoms happen anyway.
The CMI also lists “common” effects (up to 1 in 10 people): dizziness, indigestion, burping, wind, bloating, reflux or heartburn, an inflamed stomach, dry mouth, gallstones, hair loss, injection-site reactions, altered taste and changes in skin sensation. People with diabetes can also get low blood sugar. Wegovy CMI.
Do the side effects of Wegovy go away?
For most people, yes. In the STEP 1 to 3 trials, the median episode lasted 8 days for nausea, 3 days for diarrhoea and 2 days for vomiting. Constipation lasted longer, with a median of 47 days. The CMI says most side effects are “minor and temporary”.
Wegovy starts at a low dose and goes up every four weeks over about 16 weeks before reaching the usual 2.4 mg dose. Your doctor decides the pace. If side effects worry you or do not settle, the CMI says to speak to your doctor.
Some people do stop. In STEP 1, 7.0% of people on semaglutide stopped because of side effects, compared with 3.1% on placebo, and 4.5% stopped because of stomach side effects specifically. STEP 1, NEJM 2021; Wharton et al. 2021.
Which Wegovy side effects are serious?
Serious Wegovy side effects are uncommon to very rare, but they need prompt medical care. The CMI lists five, each with its own frequency. For any of them, it says to call your doctor straight away or go to the emergency department at your nearest hospital.
| Serious side effect | What it can feel like | How often (CMI) |
|---|---|---|
| Inflamed pancreas (acute pancreatitis) | Severe, long-lasting stomach pain, with or without vomiting, that may spread to the back | Uncommon (up to 1 in 100) |
| Diabetic eye disease getting worse | Changes in vision, in people with diabetes | Common in people with diabetes |
| Severe allergic reaction | Trouble breathing, swelling of the face or throat, wheezing, fast heartbeat, pale cold skin, dizziness | Rare |
| Bowel obstruction | A severe form of constipation with stomach ache, bloating and vomiting | Not known |
| Sudden vision loss (NAION) | Painless loss of vision in one eye | Very rare (up to 1 in 10,000) |
Source: Wegovy CMI. NAION is non-arteritic anterior ischaemic optic neuropathy, a problem with blood flow to the optic nerve.
In the trials, gallstones affected 1.6% of people on Wegovy compared with 1.1% on placebo, and confirmed acute pancreatitis affected 0.2%. Heart rate rose by an average of 3 beats per minute. Wegovy Australian PI.
When should you get urgent help?
Get medical help straight away for severe stomach pain that does not go away, signs of an allergic reaction, sudden loss of vision or rapidly worsening eyesight, or severe constipation with bloating and vomiting. These are the warning signs the CMI singles out.
- Call 000 for trouble breathing, swelling of the face or throat, or collapse.
- Go to your doctor or emergency department for severe, ongoing stomach pain, with or without vomiting.
- Contact your doctor immediately for any sudden change in vision.
- Too much medicine: call the Poisons Information Centre on 13 11 26, even if you feel fine.
- Before surgery or sedation: tell the team you take Wegovy. Food or liquid has entered the lungs during anaesthesia in some people taking medicines like it.
Does Wegovy cause hair loss?
Hair loss is listed as a common side effect. In the weight-management trials it affected 2.5% of people on Wegovy 2.4 mg compared with 1.0% on placebo. The PI says cases were mainly mild, most people recovered while staying on treatment, and it was reported more often in people who lost 20% or more of their weight.
At the higher 7.2 mg dose, hair loss was reported in 5.3% of people compared with 1.0% on placebo. A change in skin sensation, such as tingling or sensitivity, was much more common at 7.2 mg: 21.6% compared with 0.3% on placebo. At 2.4 mg it was 2.1% compared with 1.2%.
The CMI says the skin-sensation change “usually goes away over time”. Wegovy Australian PI; STEP UP, Lancet Diabetes & Endocrinology 2025.
Is the weight loss just from feeling sick?
No. An analysis of the STEP 1 to 3 trials found that less than 1 percentage point of the extra weight lost on semaglutide was explained by stomach side effects. People who had no nausea or vomiting lost weight too.
That matters because feeling sick is not a sign the medicine is “working”. If side effects are making it hard to eat or drink, that is a reason to talk to your doctor, not to push through. Wharton et al. 2021.
Who needs to take extra care with Wegovy?
The CMI asks you to tell your doctor before starting if you have stomach-emptying problems (gastroparesis) or a history of depression or suicidal thoughts. It also says not to use Wegovy during pregnancy and to stop at least two months before a planned pregnancy.
- Gastroparesis (slow stomach emptying): people with it may have serious stomach side effects.
- Mental health: talk to your doctor about any history of depression, suicidal thoughts or major mental illness.
- Other GLP-1 medicines: Wegovy is not combined with other medicines of the same type.
- Diabetes medicines: low blood sugar is more likely if you also take insulin or a sulfonylurea.
Your doctor and pharmacist can go through your own history. Wegovy CMI.
What helps with eating on queasy days?
The CMI’s main practical advice is to drink enough fluid, because vomiting and diarrhoea can cause dehydration. Beyond that, general food habits for a smaller appetite can make meals easier to manage; they do not change how the medicine works.
- Smaller meals, eaten slowly, stopping when comfortably full.
- Sips of water through the day rather than large amounts with meals.
- Plain, low-fat foods on days when rich or fried food feels too much.
- Some protein at each meal, so smaller portions still count.
More detail: foods for queasy days, the GLP-1 portion guide and the free 7-day Wegovy food plan. A doctor or Accredited Practising Dietitian can tailor this to you.
How do you report a Wegovy side effect?
Tell your doctor or pharmacist first. You can also report a suspected side effect directly to the Therapeutic Goods Administration (TGA), which uses these reports to spot safety problems. Report to the TGA.
Wegovy and Ozempic contain the same medicine at different doses, so their side effects overlap. Compare them in Ozempic vs Wegovy, or read Ozempic side effects.
What are the most common side effects of Wegovy?
Nausea, diarrhoea, vomiting, constipation and stomach pain. In the trials summarised in the Australian Product Information, nausea affected 38.3% of people on Wegovy compared with 14.0% on placebo, and diarrhoea affected 26.8% compared with 14.3%.
Do the side effects of Wegovy go away?
For most people, yes. In the STEP 1 to 3 trials the median episode lasted 8 days for nausea, 3 days for diarrhoea and 2 days for vomiting; constipation lasted longer, with a median of 47 days. Talk to your doctor if side effects do not settle.
How many people stop Wegovy because of side effects?
In STEP 1, 7.0% of people on semaglutide stopped because of side effects, compared with 3.1% on placebo. Across the STEP 1 to 3 trials, 4.3% stopped because of stomach side effects.
Does Wegovy cause hair loss?
Hair loss is listed as a common side effect. It affected 2.5% of people on the 2.4 mg dose compared with 1.0% on placebo, was mainly mild, and most people recovered while staying on treatment. It was more common at the 7.2 mg dose.
What Wegovy side effects need urgent care?
Severe stomach pain that does not go away, signs of an allergic reaction such as trouble breathing or a swollen face or throat, sudden vision loss, and severe constipation with bloating and vomiting. Call your doctor straight away or go to the emergency department.
Is weight loss on Wegovy caused by feeling sick?
No. An analysis of the STEP 1 to 3 trials found less than 1 percentage point of the extra weight loss was explained by stomach side effects.
Related explainers: Wegovy in Australia · Wegovy doses · Is Wegovy on the PBS? · Ozempic vs Wegovy · Mounjaro side effects
Primary sources checked for this page.
- Wegovy FlexTouch Consumer Medicine Information (Australia), prepared July 2026.
- Wegovy Australian Product Information, revised 3 November 2026.
- Wilding et al., STEP 1, New England Journal of Medicine, 2021.
- Wharton et al., gastrointestinal tolerability in STEP 1 to 3, Diabetes, Obesity and Metabolism, 2021.
- Wharton et al., STEP UP (semaglutide 7.2 mg), Lancet Diabetes & Endocrinology, September 2025.
- PBS medicine status: semaglutide (Wegovy), established cardiovascular disease with obesity, retrieved 9 November 2026.
- PBS: PBAC cycle timeframe 2026–2027, retrieved 9 November 2026.
- TGA ARTG entry 522753: Wegovy semaglutide 1.5 mg tablets, ARTG date 3 November 2026.
- TGA: report a side effect or problem (consumers).
Editorial method: Australian regulatory documents (the TGA-approved Product Information and Consumer Medicine Information, the TGA and the PBS) were checked first, then peer-reviewed trial publications. Trial numbers are group averages and say which analysis they come from. Status statements are dated and may change. A named clinical review is pending; until then this is editorial research, not clinical opinion. See the Preptide editorial policy.
Important: General information only, not medical advice. Brand names are registered trademarks of their respective owners; Preptide is independent and is not affiliated with, endorsed by or sponsored by any medicine manufacturer. Preptide is food, not medication, and does not prescribe, sell, recommend or promote prescription medicines. Talk to your doctor or pharmacist about any medicine. In an emergency call 000. Read our editorial policy and Health Acknowledgement.