For individuals with a BMI ≥30 kg/m2 or a BMI of 27 to 29.9 kg/m2 with comorbidities, who have not met weight loss goals with diet and exercise alone, various guidelines suggest adding pharmacologic therapy to lifestyle intervention

Though to be clear – Drug therapy does not cure obesity. You should know that when the maximal effect has been achieved, weight loss ceases. Meaning that you might lose 5 extra kgs or 10 lbs on the drug and once that is achieved, that is all you will get.  When drug therapy is discontinued, weight is expected to rise again. Though for some people taking medication has additional benefits because it helps them commit to the associated lifestyle changes required

However, the role of drug therapy has been questioned because of concerns about effectiveness especially long-term effectiveness after you come off them, the potential for abuse, potential side effects and often considerable cost.

So what is considered effective?  There is some minor variation in the literature but

  • Weight loss should exceed 2 kg or 4 lbs during the first month of drug therapy.  After 3-6 months you should have lost about 5% of your body weight, and remain at this level.  If you have not achieved this then it may be worthwhile changing the medication or stopping them.
  • Keep in mind though it is not just about the weight.  5% may not seem like  a lot but a weight loss of 5 to 10% can substantially reduce the development of diabetes, reduce blood pressure and risk factors for cardiovascular disease

Obviously, you would need a script for these, so you will have to discuss them with your doctor first.  So let’s cover some of the common options, how they work, possible side effects, how effective they are and at what cost.  Then it is up to you and your doctor to weigh up the pros and cons of these options and decide.

Keep in mind that you must discuss these with your health professional – side effects are not definitely going to happen, these are potential side effects. Some are less serious but more common and others are less common but more serious and the ones I am giving you generally fall into those two categories, but this not a complete summary of all the medication side effects and interactions.  You can find more information on websites like and by talking to your health professional first.