What is semaglutide?
It is an active substance, not a single product name. Medicines containing it include Wegovy, Ozempic and Rybelsus. Although the ingredient is the same, approved uses differ. Ozempic and Rybelsus treat type 2 diabetes. Wegovy is used for weight management. [15] [17] [18]
Information about one product should therefore not automatically be applied to another. The formulation, dose studied and patient group also matter.
How does it affect appetite and blood sugar?
Semaglutide mimics GLP-1, a hormone involved in the body's response to food. It helps increase fullness and reduce hunger, making it easier to eat less. [15]
In people with diabetes, it also helps control blood sugar. This does not mean it replaces every other part of treatment. The doctor considers existing medicines, conditions and test results. [17]
Who might benefit?
Treatment of excess body weight concerns obesity, or overweight with an additional weight-related health problem. The medicine is used alongside changes to nutrition and physical activity. Wanting to lose a few kilograms alone does not establish a need for such treatment. [15]
Detailed eligibility and medicine forms in the EU
For Wegovy in adults: a BMI of at least 30, or at least 27 with a weight-related condition. BMI compares weight with height. Current EMA information covers injection pens and tablets. Injections also have a defined indication in adolescents aged 12 and over; tablets are for adults. [16]
How much weight was lost in the studies?
In STEP 1, people taking semaglutide with lifestyle-change support lost an average of about 15% of body weight over 68 weeks. Participants were adults with obesity or overweight plus another health problem, without diabetes. [19]
15% of a starting weight of 100 kg equals 15 kg. This illustrates how to read the result. A group average does not tell us how much a particular person will lose.
Detailed STEP 1 data
The study enrolled 1,961 participants, who received support with lifestyle changes. After 68 weeks, people taking semaglutide had lost an average of 14.9% of their body weight. The study tested semaglutide 2.4 mg. The analysis also accounted for treatment discontinuation. Gastrointestinal problems led 4.5% of people taking semaglutide to stop treatment. The dose identifies the study group; it is not an instruction for use or a statement of the current maximum dose. [19]
Are the benefits only about weight?
No. A separate trial also examined heart attacks, strokes and cardiovascular deaths. Participants had overweight or obesity and established heart or blood-vessel disease, but no diabetes. The trial found a benefit from semaglutide in reducing these events over more than three years of follow-up. [20]
This result applies to that particular group. It is not evidence that the medicine provides the same protection to every healthy person.
Detailed SELECT results
17,604 people aged 45 and over. Mean follow-up: 39.8 months. In the semaglutide group, cardiovascular death, non-fatal heart attack or non-fatal stroke occurred in 6.5% of participants. Adverse effects led 16.6% of people taking semaglutide to discontinue treatment. [20]
What may happen after treatment ends?
In follow-up of some participants after treatment ended, an average of about two-thirds of the lost weight returned. Structured lifestyle support also ended. The whole effect therefore cannot be attributed solely to stopping the medicine. [21]
The finding is a reminder that a treatment plan should also cover weight maintenance. A short course does not guarantee a lasting result.
Who was followed after stopping treatment?
This was a selected subgroup of 327 people from STEP 1. Follow-up continued for a year after 68 weeks of treatment. Not everyone regained the same amount, and not everyone regained all the weight they had lost. [21]
Which side effects should you know about?
Nausea, vomiting, diarrhoea, constipation and abdominal pain are common. Vomiting and diarrhoea can cause dehydration. More serious problems are also possible, including pancreatitis and gallstones. Severe, persistent abdominal pain requires urgent medical contact. [16]
The EMA classified a type of optic nerve damage as a very rare adverse effect of semaglutide. Sudden loss or rapid deterioration of vision requires urgent medical help. [23]
Tell the care team about treatment before anaesthesia. Pregnancy, plans for pregnancy and other medicines also need discussion. Semaglutide is not used during pregnancy. Certain diabetes medicines increase the risk of blood glucose falling too low. [16]
Is it a prescription medicine?
Yes. Medicines containing semaglutide are authorised in the EU. A prescription, product selection and assessment of whether treatment is appropriate require a medical consultation. EU authorisation does not mean every form is currently available or reimbursed in Poland. [15] [17] [18]
What is new about semaglutide?
Hunger has returned before the next dose of Ozempic. Can you have the injection early?
Read the new eight-chapter profile of semaglutide
Semaglutide and muscle: September 2026 STEP UP analysis
Semaglutide: tablets and new safety information — a separate article about more recent findings and what they mean.
We read the publications discussed as the authors' summaries, not full articles. The semaglutide trials listed on this page were funded by Novo Nordisk.
Where does this information come from?
Show sources and how they were checked
- Wegovy
EU regulator · description updated 26.08.2026 · page read. Accessed: 02.11.2026.
- EMA: Wegovy — polska informacja o produkcie
EU regulator · updated 26 October 2026 · selected indication, safety and leaflet sections reviewed, not the whole PDF. Accessed: 2 November 2026.
- Ozempic
EU regulator · page reviewed; the historical patient summary is not used to establish current doses. Accessed: 2 November 2026.
- Rybelsus
EU regulator · description updated 21 August 2025 · page reviewed. Accessed: 2 November 2026.
- Once-Weekly Semaglutide in Adults with Overweight or Obesity
Study publication · online 10 February 2021 · PubMed abstract reviewed through the search index; full text not read · DOI: 10.1056/NEJMoa2032183. Accessed: 2 November 2026.
- Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes
Study publication · online 11 November 2023 · PubMed abstract reviewed · DOI: 10.1056/NEJMoa2307563. Accessed: 2 November 2026.
- Weight regain and cardiometabolic effects after withdrawal of semaglutide: The STEP 1 trial extension
Publication of post-trial follow-up · online 19 May 2022 · PubMed abstract reviewed · DOI: 10.1111/dom.14725. Accessed: 2 November 2026.
- PRAC concludes eye condition NAION is a very rare side effect of semaglutide medicines Ozempic, Rybelsus and Wegovy
Safety announcement · 06.06.2025, corrected 13.06.2025 · full page. Accessed: 02.11.2026.