What you need to know about the updated Canadian guidelines on pharmacotherapy for obesity

In this updated version of the Canadian Clinical Practice Guidelines on Adult Obesity (last revised in 2022) published in CMAJ, Obesity Canada makes 13 recommendations—six new and seven updated—for clinicians regarding pharmacotherapy in the management of obesity in adults.These new 2025 guidelines build on the principles established in the 2020 guidelines, which emphasized the importance of patient-centered care, shared decision-making, and recognizing and reducing weight-related stigma and bias in clinical practice.Building on the research conducted for the 2022 Pharmacotherapy Review, the authors conducted a systematic literature review between January 2022 and July 2024, supplemented by relevant trials published up to May 2025, to identify studies evaluating the efficacy and safety of obesity medications currently approved by Health Canada. They also conducted 13 targeted studies on the management of weight-related complications in several subpopulations with significant weight-related health problems.These new guidelines are also based on input from primary care physicians, obesity specialists, and patient partners.The authors therefore recommend that clinicians use central adiposity measures such as waist circumference, waist-to-hip ratio, or waist-to-height ratio, in addition to ethnicity-specific body mass index (BMI) thresholds or adiposity-related complications to guide the decision to initiate pharmacotherapy.Furthermore, they emphasize that pharmacotherapy for obesity should be combined with health behaviour changes and individualized based on each person's specific health needs to address individual values, preferences, and goals, thus ensuring better long-term adherence.According to the 2025 guidelines, pharmacotherapy should be used long-term, when effective, to:prevent weight regain and reversal of health benefits achieved with pharmacotherapy: semaglutide 2.4 mg weekly; tirzepatide 10 mg or 15 mg weekly; orlistat 120 mg 3 times dailymaintain weight loss and prevent weight regain through simple health behaviour changes: liraglutide 3 mg daily; orlistat 120 mg 3 times daily; Tirzepatide 10 mg or 15 mgObesity Canada also makes several specific recommendations for particularly at-risk subpopulations, while advocating "shared decision-making, informed by clinical priorities and patient preferences."Obesity-related complicationsIn individuals with a BMI ≥ 30* or a BMI ≥ 27* with obesity-related complications:Semaglutide 2.4 mg weekly (BMI ≥ 27*)Tirzepatide 5 mg, 10 mg, or 15 mg weekly (BMI ≥ 27*)Liraglutide 3 mg daily (BMI ≥ 27*)Naltrexone-bupropion 16 mg/180 mg twice daily (BMI 27–45*)Orlistat 120 mg 3 times daily (BMI 28–47*)Cardiovascular diseasesTo reduce the occurrence of major adverse cardiovascular events in individuals with established ASCVD and a BMI ≥ 27*, in addition to standard care for MCVA: Semaglutide 2.4 mg weekly.Heart failure with preserved ejection fractionIn people living with heart failure with preserved ejection fraction and a BMI ≥ 30*, in addition to standard care, pharmacotherapy should be used for weight loss and:A combination of reducing cardiovascular mortality or worsening of a heart failure event: tirzepatide 15 mg weeklyImproving heart failure symptoms: semaglutide 2.4 mg weekly; tirzepatide 15 mg weeklyDiabetesIn people living with prediabetes, pharmacotherapy should be used for weight loss and:Reducing the risk of progression to type 2 diabetes: liraglutide 3 mg daily (BMI ≥ 27*); orlistat 120 mg 3 times a day (BMI ≥ 30*); Tirzepatide 5 mg, 10 mg, or 15 mg weekly (BMI ≥ 27*)To achieve normoglycemia: Semaglutide 2.4 mg weekly (BMI ≥ 30*)In people living with type 2 diabetes, the following pharmacotherapy should be used to lose weight and improve glycemic control:Semaglutide 2.4 mg weekly (BMI ≥ 27*)Tirzepatide 10 mg or 15 mg weekly (BMI ≥ 27*)Liraglutide 3 mg daily (BMI ≥ 27*)Naltrexone-bupropion 16 mg/180 mg twice daily (BMI 27–45*)Orlistat 120 mg 3 times daily (BMI 27–43*)MASHFor people with For those living with metabolic steatohepatitis (MASH), pharmacotherapy may be offered for weight loss and:Resolution of MASH without worsening of fibrosis: semaglutide 2.4 mg weekly; liraglutide 1.8 mg daily (BMI ≥ 25*); tirzepatide 5 mg, 10 mg, or 15 mg weekly (BMI 27–50*)Improvement of fibrosis without worsening of MASH: semaglutide 2.4 mg weekly; Tirzepatide 5 mg, 10 mg, or 15 mg weekly (BMI 27–50*)Obstructive sleep apneaPharmacotherapy should be used for weight loss and to improve the apnea-hypopnea index in people with moderate to severe obstructive sleep apnea and a BMI ≥ 30*, and who are:Unwilling or unable to use positive airway pressure therapy: tirzepatide 10 mg or 15 mg; Liraglutide 3 mg dailyUnder positive airway pressure therapy: tirzepatide 10 mg or 15 mgOsteoarthritisIn people living with knee osteoarthritis and a BMI ≥ 30*, pharmacotherapy should be offered for weight loss and knee pain reduction (semaglutide 2.4 mg weekly).Other conditionsSetmelanotide up to 3 mg daily may be offered for weight management in people with a BMI ≥ 30* and:Bardet-Biedl syndromeBiallelic proopiomelanocortin, proprotein convertase subtilisin/kexin type 1, or leptin receptor deficiency genetically confirmed due to variants interpreted as pathogenic, probably pathogenic, or of uncertain significance.*See Recommendation 1: Use central adiposity measures such as waist circumference, waist-to-hip ratio, or waist-to-height ratio, in addition to ethnicity-specific body mass index (BMI) thresholds or adiposity-related complications to guide the decision to initiate pharmacotherapy.Finally, the authors advise against the use of compounded, prescription, or over-the-counter medications other than those approved in Canada for weight loss in individuals with excessive adiposity.The authors emphasize that pharmacotherapy recommendations for the management of obesity should always emphasize the need for a comprehensive patient assessment and to address, where possible, factors contributing to obesity. Anti-obesity medications are recommended in conjunction with health-related behaviour changes, including medical nutrition therapy and physical activity.In addition to these guidelines, Obesity Canada has developed key messages for health professionals, for people living with obesity as well as a clinical decision tool.This article has been translated from its original French and first appeared on our sister site Profession Santé.

What you need to know about the updated Canadian guidelines on pharmacotherapy for obesity

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