Ozempic vs Wegovy: the same medicine at different doses
Ozempic (semaglutide) and Wegovy (semaglutide) contain the same molecule, injected once a week. Its half-life is about a week, which is why weekly dosing works. What separates the two brands is the dose and the registered use.
In Malaysia, Ozempic was approved by the Drug Control Authority on 13 February 2020 for type 2 diabetes, and its package insert also lists a cardiovascular-risk use in adults with type 2 diabetes, the evidence for which is outside this article. The dose starts at 0.25 mg for 4 weeks, moves to 0.5 mg, and goes up to 1 mg weekly. The Malaysian package insert does not recommend going above 1 mg.
Wegovy was approved on 8 June 2023 for weight management in adults with a BMI of 30 or more, or 27 to under 30 with at least one weight-related condition. Its dose climbs over 16 weeks (0.25, 0.5, 1, 1.7, then 2.4 mg weekly), and the package insert advises delaying a step or going back one if stomach symptoms are significant. Use under 18 has not been established.
Rybelsus (semaglutide) is the tablet. It is taken daily, starting at 3 mg for a month, then 7 mg, up to 14 mg, on an empty stomach with up to half a glass (120 ml) of water, then nothing else by mouth for at least 30 minutes. It was approved on 12 May 2022, and its Malaysian package insert covers type 2 diabetes only.
Saxenda: liraglutide, the daily injection
Saxenda (liraglutide) is injected daily. The dose starts at 0.6 mg and rises by 0.6 mg at least a week apart, to 3.0 mg. In Malaysia it is registered for weight management in adults, with the same BMI rule as Wegovy, and for adolescents from 12 years with obesity and a body weight above 60 kg. For adults the package insert says to stop after 12 weeks on 3.0 mg if less than 5% of body weight has been lost.
In the 56-week SCALE trial of 3,731 adults without diabetes, liraglutide 3.0 mg produced an average loss of 8.4 kg against 2.8 kg on placebo. The Malaysian obesity guideline notes stomach side effects with liraglutide 3 mg, and a rise in resting heart rate.
Mounjaro: tirzepatide, the dual agonist
Mounjaro (tirzepatide) is one molecule that acts on two receptors, GIP and GLP-1. Both receptor types sit in the pancreas, gut, kidney and the appetite areas of the brain, and GIP receptors are also found on fat cells. Its GIP activity is similar to the body's own GIP, while its GLP-1 activity is lower than the body's own GLP-1. A fatty acid chain lets it bind albumin in the blood, giving a half-life of about 5 days, so it is also a weekly injection.
The dose starts at 2.5 mg weekly for 4 weeks, then 5 mg, with 2.5 mg steps after at least 4 weeks each and a maintenance dose of 5, 10 or 15 mg. In Malaysia one brand covers two uses: type 2 diabetes, and weight management in adults with a BMI of 30 or more, or 27 to under 30 with at least one weight-related condition. In the United States the weight use is sold under a second name, Zepbound (tirzepatide), which is not registered in Malaysia.
How much weight did people lose on each medicine, in its own trial?
Each result below comes from a different trial, with different people and a different length. They are averages, with a placebo group beside them, and they are not a league table. In STEP 1, 1,961 adults without diabetes lost an average of 14.9% of body weight on semaglutide 2.4 mg over 68 weeks, against 2.4% on placebo. In SURMOUNT-1, 2,539 adults without diabetes lost an average of 15.0%, 19.5% and 20.9% on tirzepatide 5, 10 and 15 mg over 72 weeks, against 3.1% on placebo, with diet and activity counselling in both groups. Liraglutide's SCALE result is in the section above, given in kilograms.
A 25 mg semaglutide tablet was tested in the OASIS 4 trial: 307 adults over 64 weeks lost 13.6% on average against 2.2% on placebo. That tablet is not registered in Malaysia. Only a trial that puts two medicines against each other can compare them directly. One such weight trial exists for semaglutide and tirzepatide, SURMOUNT-5, and a separate article covers it.
The medicines also differ in the trials done in heart and kidney conditions. That evidence is separate for each medicine, and it is outside this article.
Which side effects are shared, and which differ?
The shared ones are stomach effects: nausea, vomiting, diarrhoea and constipation, more marked while the dose steps up. Stomach emptying slows with all of these medicines, which is part of how they work. It is also why the Malaysian regulator advises telling every doctor before a procedure that needs general anaesthesia or deep sedation. Vomiting and diarrhoea can dehydrate, which can worsen kidney function. Gallbladder problems are more frequent with weight loss on these medicines. In July 2026 NPRA warned about severe pancreatitis in these classes: severe, persistent abdominal pain that may reach the back needs urgent care, and the medicine is stopped at once if pancreatitis is suspected and not restarted if it is confirmed.
Some effects are specific. Semaglutide carries a caution for diabetic retinopathy: the Malaysian Wegovy package insert does not recommend use in uncontrolled or unstable diabetic retinopathy. In June 2025 the European Medicines Agency's safety committee concluded that NAION, an eye condition that can cause sudden loss of vision, is a side effect of semaglutide in the lowest frequency band, which may affect up to 1 in 10,000 people taking it. That review covered semaglutide only. Sudden loss of vision needs same-day assessment by an ophthalmologist. Liraglutide 3 mg raises the resting heart rate. Tirzepatide has a note on the contraceptive pill. The US label advises a non-oral method, or a barrier method added, for 4 weeks after starting and after each dose step. The Malaysian insert reports that after one 5 mg dose, peak ethinyl estradiol fell 59%, which it does not consider clinically relevant, and it advises no change in pill dose. That is a question for the assessment.
Pregnancy planning differs by medicine. Semaglutide is stopped at least 2 months before a planned pregnancy and is not used while breastfeeding. Tirzepatide is stopped at least 1 month before, and contraception is advised for women who could become pregnant. Liraglutide is not used in pregnancy and is stopped if one is planned. What is checked before a first prescription is set out in what a doctor checks before prescribing GLP-1 medication, and the side effects with trial figures are in weight-loss injection side effects: what to expect.
What is registered in Malaysia, and what is not?
The National Pharmaceutical Regulatory Agency (NPRA) said on 22 July 2026 that 40 products in these classes are registered in Malaysia, mainly for type 2 diabetes, with selected products also approved for weight management. On its register, searched on 30 September 2026, semaglutide appears as Ozempic and Rybelsus (type 2 diabetes) and Wegovy (weight management), liraglutide as Saxenda (weight management), tirzepatide as Mounjaro (both uses) and dulaglutide as Trulicity (type 2 diabetes, from age 10). A stand-alone liraglutide product for diabetes did not appear in that search.
Not on the register on that date: Zepbound (tirzepatide), the 25 mg oral semaglutide tablet sold in the United States as a Wegovy tablet, orforglipron, a tablet approved in the US in 2026 for weight management in adults, and retatrutide. The Health Ministry, as reported in August 2026, has said that no regulator anywhere has approved retatrutide and that no product was registered as of 17 August 2026, so pens sold online as "Reta" are unregistered.
These medicines are Group B poisons, supplied only by registered doctors or pharmacists against a valid prescription. A registered product carries a MAL number and a hologram. The number can be checked on NPRA's Quest3+ search, and the hologram with a pharmacy's Meditag decoder. The Malaysian Obesity Society warned in January 2026 that products sold online may be unregistered, made without good manufacturing practice, kept out of the cold chain, of uncertain purity, or a different substance from the label.
The Malaysian obesity guideline was published in May 2023, before Mounjaro was registered here for weight management. Its list of medicines includes high-dose liraglutide and semaglutide, and tirzepatide is not in it.
How is the choice between them made?
The guideline says to choose a medicine on its efficacy, side effects and cost. Its Recommendation 5 (Grade A) says to use medicine only alongside diet, exercise and behaviour change, and sets the threshold used in this article: a BMI of 30 or more, or 27 or more with a weight-related condition. A summary box in the guideline gives 27.5 for that second figure, so the two differ slightly. This article quotes the graded recommendation.
Beyond that, the choice turns on the person. Whether type 2 diabetes is present matters, because the brands are registered for different uses. Plans for a pregnancy change the timing. A daily or weekly rhythm, and a tablet or an injection, suit different lives. Decisions about heart, kidney and diabetes treatment sit with the person's own physician.
Once a medicine is started, the guideline sets face-to-face review monthly for 3 months, then at least every 3 months, and says to stop if a loss of more than 5% has not been reached by 3 months, or if significant safety or tolerability problems appear. What a follow-up checks covers that. Obesity is chronic, courses of 6 months or less do not sustain the loss, and weight returns after stopping. Rebound weight after stopping GLP-1 sets out the evidence.
Which medicine is prescribed, if any, is settled at the evaluation and can be revisited at every review.
