In Canada, there are 2 prescription medications that are available for weight loss: orlistat (Xenical®) and liraglutide (Saxenda®). These medications are used along with a reduced-calorie diet by people with a BMI of 30 or higher and by people with a BMI of 27 or higher who also have other risk factors (e.g., high blood pressure, type 2 diabetes, abnormal cholesterol). For this latter group, liraglutide should be used only if the person has tried a previous weight loss intervention (i.e., exercise program) that was not effective. Orlistat is also used to maintain weight loss and reduce the risk of regaining weight for people who have lost weight.

Previous medications for weight loss, including diethylpropion (Tenuate®, Tenuate® Dospan) and sibutramine (Meridia®), are no longer available in Canada.

Orlistat (Xenical®)
Orlistat prevents enzymes (called lipases) that break down fat from working. This keeps fat in the intestine, and it passes through the body without being absorbed. Orlistat reduces fat absorption by about 30%. The body takes in fewer calories, resulting in weight loss.

The most frequent side effects of orlistat are:

  • oily spotting/discharge
  • inability to hold or sudden urge to have a bowel movement
  • gas with leaky bowel movements
  • oily bowel movements
  • increased number of bowel movements

The risk for these side effects is higher if more than 30% of your daily calories are obtained from fat, or if any single meal has a very high fat content.

Do not use orlistat if you have problems absorbing nutrients from foods. It should also not be used if you have problems with bile flow in your liver.

Orlistat may decrease the absorption of vitamins A, D, E, K, and beta-carotene. You may be advised to take a multivitamin containing these particular vitamins on a daily basis, at a separate time from when you take orlistat. For more information about orlistat, see our drug information article.

Liraglutide (Saxenda®)
Liraglutide activates receptors (called GLP-1 receptors) located in the brain. It delays the movement of food into the intestines and it affects areas in the brain involved in appetite control. This triggers a greater feeling of fullness after eating meals and a reduced appetite. It contributes to weight loss by reducing the amount of calories you take in.

Liraglutide (Saxenda®) is injected under the skin using a pre-filled, multi-dose pen.

The most frequent side effects are:

  • nausea, vomiting, and diarrhea
  • lower appetite
  • abdominal pain
  • indigestion
  • constipation
  • heartburn
  • flatulence
  • pain, redness, or irritation at the injection site on the skin

Liraglutide should not be used if you have a personal history or family history of medullary thyroid cancer or multiple endocrine neoplasia syndrome type 2 (MEN 2). For more information about liraglutide (Saxenda®), see our drug information article.

Speak to your doctor, pharmacist, or dietitian about weight management plans and resources available in your area.