The 2025 Canadian guideline update on medicines for obesity in adults

Why this study matters

A clinical practice guideline is a document written by an expert panel to help clinicians decide how to treat a condition. This one updates the medicine (pharmacotherapy) section of the 2020 Canadian adult obesity guideline and a 2022 revision. Since then, new trials and new medicines have changed the field. For Canadian readers, this is the document clinicians are most likely to follow when discussing medicines for obesity, so it helps to know what it covers and how it was built.

Who was in the study

A guideline is not a study with participants. This one is aimed at clinicians caring for adults aged 18 years and older living with obesity and weight-related health conditions. The panel engaged primary care physicians, obesity medicine specialists, and people with lived experience of obesity to give feedback on the recommendations.

What the researchers did

The panel followed the same methods as the 2020 Canadian guideline. It used the AGREE instrument (a standard checklist for guideline quality) and the Shekelle framework to grade evidence and write recommendations. Building on the search done for the 2022 revision, the panel ran a systematic literature review covering January 2022 to July 2024, supplemented with relevant trials published through May 2025. It also ran 13 targeted searches on managing weight-related complications in 13 specific groups of people with important adiposity-related health issues.

What they found

The update contains 13 recommendations: 6 new and 7 revised since the 2022 revision. All of the 2020 recommendations on medicines were updated (R32-C114). The main points, as stated in the published summary, are:

• Measures of central adiposity (fat around the middle), together with ethnicity-specific body mass index (BMI, a number that compares weight with height) and adiposity-related complications, should guide the decision to start a medicine.
• Medicines for obesity should be used together with health behaviour changes.
• Treatment should be individualized to a person's specific health needs and in keeping with their values and preferences.
• The recommendations support long-term use of obesity medicines for sustained weight loss and for maintaining weight loss.
• The guideline gives recommendations on specific medicines with proven benefit in specific groups: people with atherosclerotic cardiovascular disease, heart failure with preserved ejection fraction, metabolic dysfunction-associated steatohepatitis (a liver disease), prediabetes, type 2 diabetes, obstructive sleep apnea, and osteoarthritis, and people with certain single-gene causes of obesity.
• The guideline recommends against compounded medicines and against medicines other than those approved for weight loss in people with excess adiposity.

The summary concludes that pharmacotherapy in obesity leads to clinically meaningful weight loss and important improvements in obesity-related health complications, and that clinicians should use it as an integral part of treatment for people living with obesity, with or without complications.

Side effects and people who stopped

Not applicable. The guideline reviews safety evidence, but no specific side-effect figures were extracted for this page. Individual trial pages on this site report those numbers.

What this study does not tell you

• A guideline is expert interpretation of evidence. It does not itself test any treatment, and it does not tell you what is right for one person.
• The summary does not name the medicines behind each recommendation. Names, doses and trial numbers live in the full guideline and the individual trial pages.
• The extracted data note that some recommendations cover uses beyond a medicine's specific authorized indication. This guideline is not a regulatory document, and it was not audited against Canadian approval status as of September 2026.
• The literature search ended in July 2024, with supplements to May 2025. Newer trials are not included.
• Panel members made quarterly conflict-of-interest disclosures and recused themselves where needed. One panel member was employed by Obesity Canada. Individual industry relationships were not extracted.

What it means in Canada

This is the most current national guidance on medicines for obesity in adults and is the document your clinician or pharmacist is most likely to reference. It replaces the medicine content of the 2020 guideline. To learn how individual medicines are used in Canada, see semaglutide in Canada and tirzepatide in Canada. For questions about what provincial plans pay for, see public drug coverage by province.

Related reading

Other studies in this library that bear on the same question.

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