Medication is not a shortcut or a failure of effort. It is one evidence-based treatment option for a real, brain-centred, chronic condition.
Earlier modules describe excess weight as a real, genetically influenced, brain-centred, progressive, chronic condition. Behavioural treatment remains foundational. Obesity medications are now an important second treatment pillar, and bariatric surgery remains an important third pillar.
Obesity medications diminish wanting, making "on-track" food decisions easier. They also help reduce the biological pressure that defends against weight loss. They are used alongside health-behaviour change, not as a replacement for it.
Medication is not proof that effort failed. It is one way to treat the biology that effort has been working against.
Safe and effective obesity medications now play a central role in obesity care. In Canada, long-term medication options include liraglutide, naltrexone/bupropion, orlistat, semaglutide, tirzepatide, and setmelanotide for specific rare genetic obesities.
Some medications work mainly in the gut. Others act more directly on appetite biology: hunger, fullness, food reward, cravings, and the drive to eat. GLP-1-based medications such as liraglutide and semaglutide increase fullness and reduce hunger. Tirzepatide works through both GIP and GLP-1 pathways. Naltrexone/bupropion acts on appetite and reward pathways.
Outcomes have changed meaningfully. In STEP 1, semaglutide 2.4 mg with lifestyle intervention produced average weight loss of about 14.9% at 68 weeks. In SURMOUNT-1, tirzepatide produced average weight loss of about 15.0% to 20.9% at 72 weeks, depending on dose.
Medication choice should be individualized. Benefits, risks, side effects, contraindications, route of administration, cost, access, coverage, co-existing conditions, and patient preference all matter. Use authorized, prescribed medications only, and avoid counterfeit or misleadingly marketed GLP-1 products sold online or through unofficial channels.
Earlier modules have described overweight and obesity as a real, genetically influenced, brain-centred, progressive, chronic disease. They have also shown that effective treatment is not limited to willpower or lifestyle advice alone.
Behavioural treatment remains a foundational treatment pillar. Obesity medications are now an important second pillar, and bariatric surgery remains an important third pillar. The focus of this page is obesity medication.
Medical therapy has advanced substantially. Newer incretin-based therapies have produced greater average weight loss and broader health benefits than earlier medications. Semaglutide has also shown cardiovascular benefit in selected populations. At the same time, bariatric surgery remains a highly effective treatment option, especially for severe obesity.
Modern obesity care should present medication and surgery as complementary tools within chronic disease treatment, not as competing ideologies.
Obesity medications work in different ways. Some, such as orlistat, work mainly in the gut. Others act more directly on the biology of appetite, hunger, fullness, and food reward. This includes naltrexone/bupropion, liraglutide 3.0 mg, semaglutide 2.4 mg, and tirzepatide.
Liraglutide, naltrexone/bupropion, orlistat, semaglutide, tirzepatide, and setmelanotide for specific rare genetic obesities.
Liraglutide 3.0 mg and semaglutide 2.4 mg are GLP-1-based medications that increase fullness and reduce hunger. Tirzepatide works through both GIP and GLP-1 pathways and also increases fullness while decreasing hunger and calorie intake. In practical terms, these medications help quiet the biological pressures that defend against weight loss and push appetite upward.
The central role of WANTING has been established in the Wanting module. Wanting drives overeating and can make weight management much harder. Naltrexone/bupropion acts on appetite and food reward pathways, and newer incretin-based medications such as semaglutide and tirzepatide also appear to reduce hunger, food preoccupation, and cravings in many people.
The key message is that obesity medications can influence the brain systems involved in fullness, hunger, and food reward. This is why medication can be a powerful addition to behavioural treatment: it can help reduce the biological and psychological pull toward overeating while you continue to build skills, routines, and restraint.
Clinical trials are conducted to determine the safety, tolerability, and effectiveness of obesity medications. Since this module was first written, expected outcomes with medication have changed meaningfully. Earlier medications helped many people achieve modest-to-moderate weight loss. Newer incretin-based medications have moved average outcomes into a new range and have reshaped expectations for what medical obesity treatment can achieve.
Semaglutide 2.4 mg combined with lifestyle intervention produced an average weight loss of about 14.9% at 68 weeks.
Tirzepatide produced average weight loss ranging from about 15.0% to 20.9% at 72 weeks, depending on dose.
Not every person responds to every medication in the same way. Some people notice an early and powerful reduction in appetite, cravings, and food noise, while others have a smaller response or find a given medication difficult to tolerate. A limited response to one medication does not mean that another medication will not work well for the same person.
Treatment with obesity medications is also associated with improvements in weight-related health conditions such as blood pressure, blood sugar, cholesterol, physical function, and quality of life.
Many people living with overweight or obesity have internalized shame, blame, and the false idea that this condition is simply a matter of willpower. A more accurate and medically grounded view is that obesity is a complex, chronic, biologically regulated disease that is influenced by genetics, physiology, environment, and life experience.
In that framework, medication is not a shortcut or a failure. It is one evidence-based treatment option for a real chronic disease. The decision to use medication remains yours, and the role of the clinician is to explain the potential benefits, risks, alternatives, and appropriateness of treatment for your situation.
Obesity medications work best when they are part of comprehensive long-term care. That care may include behavioural treatment, nutrition support, physical activity, sleep optimization, and psychological support where appropriate.
In Canadian obesity care, pharmacotherapy should generally be considered for adults with a BMI of 30 kg/m² or above, or a BMI of 27 kg/m² or above in the presence of at least one adiposity-related complication.
Examples include hypertension, type 2 diabetes, dyslipidemia, obstructive sleep apnea, osteoarthritis, or other clinically important weight-related health problems.
Each medication has its own contraindications, cautions, and monitoring requirements. These must be reviewed carefully with the prescribing clinician.
The safest and most appropriate choice depends on the medication, medical history, concurrent medications, treatment goals, preferences, affordability, and access.
Behavioural treatment remains a foundational pillar of obesity care, but modern obesity management is best approached as chronic disease care rather than a step-by-step test of willpower. Medication can be considered at different points depending on health status, treatment goals, response to behavioural care, and preference.
Begin with behavioural treatment alone and do not use obesity medication at this time. This may be reasonable if health goals are being met, complications are limited, or the person prefers to begin without medication.
Start medication at the same time as behavioural treatment begins. This can be reasonable when earlier improvement in health, appetite control, weight-related complications, or quality of life is important.
Add medication after behavioural treatment has begun if progress is limited, weight-related complications remain active, or appetite biology continues to make change very difficult.
Add medication when behavioural treatment alone has brought someone to their BEST WEIGHT, but health, function, or quality of life are still not where they need to be.
The timing of medication initiation should be discussed with a qualified clinician and decided through shared decision-making. Once started, medication is generally titrated as needed and tolerated, continued long term if helpful, and reassessed over time.
Initiating obesity medication begins with a careful discussion of how the medication works, what benefits are being targeted, what side effects or contraindications need to be reviewed, and whether treatment fits the patient’s goals, preferences, and circumstances.
For many modern medications, treatment starts at a lower dose and is increased gradually to improve tolerability. For example, semaglutide is typically escalated stepwise to a maintenance dose, and tirzepatide is also started at a low weekly dose and increased gradually as needed and tolerated.
Because obesity is a chronic disease, medication should usually be framed as part of long-term treatment rather than a short-term fix. When effective and tolerated, pharmacotherapy is generally continued long term to help maintain benefits and reduce the risk of weight regain or regression of health improvements.
Follow-up should focus on more than the number on the scale. Assessment should include appetite response, hunger and craving control, tolerability, adherence, weight or waist-related progress if the patient wishes to track it, and improvement in obesity-related health complications, physical function, and quality of life.
Obesity medication should no longer be viewed as care available only through a narrow group of specialists. Obesity treatment can and should increasingly be delivered within routine evidence-based medical care, including primary care.
Some people may still benefit from referral to clinicians or programs with additional obesity expertise, especially when treatment is complex, when multiple health conditions are involved, or when access and coverage are difficult to navigate.
Weight bias and outdated eat-less, move-more thinking still create barriers, so some people may still need to advocate for evidence-based care.
Use only authorized, prescribed medications. Avoid unauthorized, counterfeit, or misleadingly marketed GLP-1 products sold online or through unofficial channels.