There are classes of prescription drugs recognized as consistently causing weight gain as a main side effect of the medication use. We refer to these drugs as “obesogenic”; because they promote weight gain and obesity. The question here is do you know what these drugs are and we’re you ever told that these drugs could cause you to gain weight?

In the Journal of International Obesity it was believed that approximately 9% of patients attributed the weight that they had gained due to the drugs that they were prescribed.1

The weight gain from these drugs is due to different reasons based on the mechanism of the drugs themselves.

Examples include increased appetite with corticosteroids, reduction in metabolic rate with beta-blockers, and the treatment of a disease state whereby weight was being lost as a result of the disease and now weight gain is occurring because the medication is counteracting the disease process.

The drugs that are known to promote weight gain include insulin, sulphonylureas, thiazolinidiones used for the management of diabetes; beta-blockers used for management of blood pressure and cardiac conditions; corticosteroids used in inflammatory and autoimmune diseases; cyproheptadine used for allergies; antipsychotics used for depression, anxiety, and psychiatric disorders; sodium valproate used for epilepsy; tricyclic antidepressants used for depression; and lithium used for bipolar disorder.

In 2007 researchers looked at 43 studies with a total of 25,663 subjects to determine the effect on prescription medications on weight gain.2 The study found that there was evidence of weight gain for all the drugs evaluated. The amount of weight gained during a span of 52 weeks was as high as 22 lbs.

This information is generally not readily accessible because body weight is often not recorded in published clinic trials. Additionally, physicians often do not take the time to go over every side effect of every medication that they prescribe partly because there are too many to discuss.

The Metabolism Clinic is established as the destination for weight loss and reversal of diabetes. Based in Charlotte, North Carolina.


  1. Vossenaar M, Anderson A, Lean, M, Ocke M. Perceived reasons for weight gain in adulthood. Int J Obes 28S1S67.
  2. Leslie WS, Hankey CR, Lean MJ. Weight gain as an adverse effect of some commonly prescribed drugs: a systemic review. Int J of Medicine. 395-404.