Semaglutide
A weekly injection (or daily tablet) that copies a gut hormone controlling blood sugar and appetite. Used for type 2 diabetes and weight management. Effective, and pricey off the PBS.
Quick answer: The most common side effects of semaglutide are nausea, vomiting, diarrhoea or constipation, tummy pain, headache and tiredness, mainly early on and after each dose increase. The daily tablets cause much the same side effects as the weekly injections. It’s used for type 2 diabetes and weight management. Get urgent help for severe tummy pain that won’t settle.
At a glance
- For
- Type 2 diabetes; weight management; lowering heart attack and stroke risk in some people with heart disease
- Works
- Weight: about 15% of body weight lost on average over 68 weeks at the top dose (about 2% on a dummy treatment). Diabetes: HbA1c falls by about 1.5%. Heart disease with excess weight: about 20% fewer heart attacks, strokes or heart deaths
- Cost
- Ozempic: $25 a script on the PBS for type 2 diabetes only ($7.70 concession). Wegovy for weight: private, about $250–460 a month (not on the PBS as of October 2026)
- Kicks in
- Appetite drops in the first weeks; dose stepped up every 4 weeks; weight loss builds over about a year
- Taken for
- Long term: weight usually returns after stopping
- Watch for
- Nausea, vomiting, diarrhoea or constipation, tummy pain, tiredness, gallstones
Start low, go slow, stop eating when full. A big greasy meal is how the nausea wins.
Brand names
- Ozempic (weekly injection, for type 2 diabetes)
- Wegovy (weekly injection, for weight management)
- Rybelsus (daily tablet, for type 2 diabetes)
- Wegovy tablet (daily tablet, for weight management; TGA-approved November 2026)
Semaglutide tablets
- Rybelsus is a daily semaglutide tablet for type 2 diabetes. A daily Wegovy tablet (up to 25 mg) for weight management was approved by the TGA in November 2026. It isn’t on the PBS, and its price and launch date hadn’t been announced at the time of writing.
- In a 64-week trial, people taking the 25 mg tablet lost about 14% of body weight on average, versus about 2% on a dummy tablet.
- Tablets are taken first thing on an empty stomach with a sip of water (up to about half a glass), then nothing to eat, drink or swallow for at least 30 minutes. Food stops it being absorbed.
- Side effects are much the same as the injection: mostly nausea, diarrhoea, vomiting and constipation, especially when the dose goes up.
How it works
Semaglutide mimics GLP-1, a hormone released after eating. It boosts insulin when blood sugar is high, slows stomach emptying and tells the brain you’re full.
Used for
- Type 2 diabetes, alongside diet and exercise
- Weight management in people with obesity, or overweight with a weight-related condition, alongside diet and activity
- Lowering the risk of heart attack and stroke in some people with heart disease
Side effects
Most common: nausea, vomiting, diarrhoea or constipation, tummy pain, headache and tiredness, mainly in the first weeks and after each dose step. They usually ease with time. Smaller meals, stopping when full and going easy on fatty food help.
Full side-effect list (from the product information)
How often, from the official product information. Bold = serious.
Very common more than 1 in 10
- Nausea, vomiting, diarrhoea or constipation
- Tummy pain
- Headache
- Tiredness
- Low blood sugar, if also on insulin or a sulfonylurea
Common 1 in 10 to 1 in 100
- Dizziness
- Indigestion, reflux, burping, wind or bloating
- Gastritis
- Gallstones
- Hair thinning
- Injection-site reactions
- Low blood pressure
- Low blood sugar with other diabetes medicines
- Worsening of diabetic eye disease, if already present
Uncommon 1 in 100 to 1 in 1,000
- Pancreatitis (inflamed pancreas)
- Faster heart rate
- Dizziness on standing
- Altered taste
- Raised pancreatic enzymes on blood tests
Rare 1 in 1,000 to 1 in 10,000
- Anaphylaxis (severe allergic reaction)
- Angioedema (swelling of the face, lips or throat)
Very rare fewer than 1 in 10,000
- Sudden vision loss in one eye (NAION)
Frequency not known reported, rate unclear
- Bowel obstruction
Get help urgently if
- Severe tummy pain that won’t settle, sometimes going through to the back (possible pancreatitis)
- Pain under the right ribs, fever or yellow skin (possible gallstones)
- Vomiting or diarrhoea so bad you can’t keep fluids down (risk of dehydration and kidney problems)
- Swelling of the face or throat, or trouble breathing
- Shakiness, sweating or confusion if you also take insulin or a sulfonylurea (low blood sugar)
Good to know
- Not for use in pregnancy. Stop at least 2 months before trying to get pregnant.
- Not suitable with a personal or family history of medullary thyroid cancer or MEN2.
- Tell your doctor before any surgery or anaesthetic.
- Use only TGA-approved products from a pharmacy. Compounded or online “copies” aren’t approved in Australia.
Common questions
What is the difference between Ozempic and Wegovy?
Both are weekly semaglutide injections. Ozempic is for type 2 diabetes and Wegovy is for weight management. Rybelsus is a daily semaglutide tablet for type 2 diabetes.
Is Wegovy on the PBS?
Not as of October 2026. Ozempic is PBS-subsidised for type 2 diabetes only. The PBAC has recommended Wegovy for some people with obesity who have already had a heart attack, stroke or circulation problems in the legs, but it isn’t listed yet. Until then, weight-loss use is private, roughly $250 to $460 a month.
What are the common side effects of semaglutide?
Nausea, vomiting, diarrhoea or constipation, tummy pain, headache and tiredness are very common. Severe tummy pain that won’t settle needs urgent help.
Does weight come back after stopping semaglutide?
Weight often returns after stopping. Eating enough protein and strength exercise help protect muscle.
What is semaglutide?
A GLP-1 receptor agonist medicine that copies a gut hormone, lowering blood sugar and appetite. It comes as weekly injections (Ozempic, Wegovy) and daily tablets (Rybelsus, Wegovy tablet), and is used for type 2 diabetes and weight management.
What are the side effects of semaglutide tablets?
Much the same as the injections: nausea, diarrhoea, vomiting, constipation and tummy pain are the most common, mostly early on and after dose increases. In the 25 mg weight trial, about 3 in 4 people had a gut side effect, versus about 2 in 5 on a dummy tablet.
Information only. Not a recommendation or endorsement of any product. Whether a medicine suits you depends on your health and other medicines, so talk to your doctor or pharmacist. In an emergency, call 000 (Australia) or your local emergency number. From a mobile, 112 works in most countries.
More information
- Ozempic product information
- Healthdirect: Medicines information
- STEP 1 trial: Semaglutide for weight management (NEJM)
- SELECT trial: Semaglutide and heart outcomes (NEJM)
- PBS: Semaglutide (Ozempic)
- newsGP: Wegovy recommended for PBS listing
- PBS: Wegovy listing status
- OASIS 4 trial: Oral semaglutide 25 mg for weight management (NEJM)
maladywise.com/medicines/semaglutide/