Ozempic vs Wegovy vs Mounjaro: what is the difference?

Ozempic, Wegovy, Mounjaro and Saxenda side by side

The table collects the basic facts from the EU summaries of product characteristics. Doses are the label text, not advice: the prescriber decides the dose [4, 5, 6, 13]. Milligram amounts of different substances cannot be compared with each other, because the substances are different molecules.

Read more: Semaglutide (Ozempic, Wegovy, Rybelsus) | Tirzepatide (Mounjaro) | Liraglutide (Saxenda, Victoza)

What is the difference between Ozempic and Wegovy?

Ozempic and Wegovy are semaglutide products from the same maker, and the substance is the same [1, 2]. The difference is what they are authorised for: Ozempic for type 2 diabetes in adults alongside diet and exercise, Wegovy for weight management, meaning weight loss and keeping it off, alongside a reduced-calorie diet and more physical activity [4, 5].

The other difference is strength. According to the Ozempic label, weekly doses above 2 mg are not recommended [4]. The Wegovy maintenance dose is 2.4 mg once a week, and in adults whose BMI was at least 30 at the start of treatment it can be raised to 7.2 mg if needed, after at least four weeks on 2.4 mg [5]. Wegovy also comes as a once-daily tablet [5].

Semaglutide has other names in the EU too. Rybelsus is a tablet for type 2 diabetes [15]. In the EMA database, semaglutide is also in Kayshild, authorised on 26 Mar 2026 for a liver disease (MASH), and in Kyinsu, where semaglutide is combined with insulin [16].

Read more: Ozempic and Wegovy cost and reimbursement in Finland

How does Mounjaro differ from Ozempic and Wegovy?

The active substance in Mounjaro is tirzepatide, not semaglutide [3]. Semaglutide acts like one gut hormone, GLP-1 [4]. Tirzepatide acts on the receptors of two gut hormones, GIP and GLP-1 [6].

Mounjaro has one marketing authorisation for two uses: type 2 diabetes and weight management in adults [6]. For semaglutide these uses are split between brand names, Ozempic and Wegovy [4, 5]. All three are injected under the skin once a week [4, 5, 6].

Read more: Tirzepatide trials and side effects

Which lowers weight more: Wegovy or Mounjaro?

Head to head: in SURMOUNT-5, 751 adults with obesity but without diabetes received the maximum tolerated dose of tirzepatide or semaglutide for 72 weeks. Weight fell by a mean of 20.2% with tirzepatide and 13.7% with semaglutide. The trial was open-label and funded by the maker of tirzepatide [7]A.

In diabetes: in SURPASS-2, 1,879 people with type 2 diabetes received tirzepatide or semaglutide 1 mg a week for 40 weeks. HbA1c fell by 2.01 to 2.30 percentage points with tirzepatide and 1.86 with semaglutide, and weight loss was 1.9 to 5.5 kg greater with tirzepatide [8]A.

Placebo trials separately: in STEP 1, semaglutide 2.4 mg lowered weight over 68 weeks by a mean of 14.9% and placebo by 2.4% [9]A. In SURMOUNT-1, tirzepatide lowered weight over 72 weeks by 15.0% to 20.9% depending on the dose and placebo by 3.1% [10]A. Figures from different trials cannot be compared directly, because participants and duration differed.

A higher semaglutide dose: in STEP UP, 1,407 adults without diabetes received semaglutide 7.2 mg, 2.4 mg or placebo for 72 weeks. Weight fell by a mean of 18.7%, 15.6% and 3.9%. According to the trial publication, altered skin sensation (dysaesthesia) was reported by 22.9% of the 7.2 mg group, 6.0% of the 2.4 mg group and 0.5% of the placebo group [11]A; the Wegovy label gives 21.6% for 7.2 mg in the STEP UP trials [5].

Group averages do not tell which medicine suits an individual. The prescriber weighs, among other things, other conditions, other medicines and side effects.

Read more: What happens to weight when the medicine is stopped

Side effects side by side: Wegovy vs Mounjaro

For both, the most common side effects are gastrointestinal, and they cluster in the dose-escalation period [5, 6].

Wegovy: according to the label, in the 68-week trials nausea occurred in 43.9% of those on semaglutide (placebo 16.1%), diarrhoea in 29.7% (15.9%), vomiting in 24.5% (6.3%) and constipation in 24.2% (11.1%). In the pooled label trials (STEP 1-4), gastrointestinal events led to permanent discontinuation in 4.3% [5]; in STEP 1 alone the share was 4.5% [9]A.

Mounjaro: in the weight management trial without diabetes, nausea occurred in 24.6% to 33.3% depending on the dose (placebo 9.5%) and diarrhoea in 18.7% to 23.0% (7.3%). Gastrointestinal events led 1.9% to 4.4% to stop treatment (placebo 0.5%) [6].

The figures cannot be compared directly, because they come from different trials. Rarer side effects such as gallstones and pancreatitis are covered in their own guide.

Read more: Weight-loss drug side effects and how they are managed

What about Saxenda and Rybelsus?

The substance in Saxenda is liraglutide, an older GLP-1 medicine injected once a day [13]. In SCALE, weight in 3,731 adults fell over 56 weeks by a mean of 8.4 kg with liraglutide 3.0 mg and 2.8 kg with placebo [14]A. According to the label, treatment is stopped if weight has not fallen by at least 5% after 12 weeks on the 3.0 mg dose [13].

In July 2026 the EU also authorised Ablymico for weight management, a liraglutide product whose reference medicine is Saxenda [21]. It was not in the medicines search of Kela (the Social Insurance Institution of Finland, which pays medicine reimbursements) on 13 Oct 2026 [22].

Rybelsus is semaglutide as a tablet, but its indication is type 2 diabetes [15]. The semaglutide tablet authorised for weight management is the Wegovy tablet [5]. In OASIS 4, a 25 mg semaglutide tablet lowered weight over 64 weeks by a mean of 13.6% and placebo by 2.2% [12]A.

Read more: Liraglutide (Saxenda) | Upcoming weight-loss drugs and tablets

Availability in Finland: prescription and reimbursement

Kela does not reimburse Wegovy or Mounjaro for obesity: Hila (the Pharmaceuticals Pricing Board, which decides whether a medicine is reimbursed) rejected their reimbursement applications on 14 Apr 2026 and 8 Oct 2026 [19, 20]. Ozempic, Wegovy and Mounjaro are prescription medicines in the EU [1, 2, 3]. Kela's special reimbursement for semaglutide and liraglutide covers type 2 diabetes (reimbursement right 285) [17]. For obesity, liraglutide is reimbursed only under strict conditions (reimbursement right 3051, Kela's code for liraglutide reimbursement in obesity) [18].

Prices, Kela's conditions and the routes to a prescription are in the cost guide. Products sold without a prescription and their risks have their own guide.

Read more: What a weight-loss drug costs and how to get one | Weight-loss drugs without a prescription: risks and the law