Users of the popular Ortho-Evra birth control patch are exposed to 60% more hormones than birth control users, therefore they are at a higher risk for blood clots and other serious side effects. Until recently, it was believed that the patch and the pill had similar risks of side effects, however, recently it has been found that because the patch delivers the hormones via the bloodstream as opposed to the pill which is swallowed and digested first the user is subjected to higher hormone levels initially and continuously. A new warning will be on the label of the patch as of now.
Users of any hormone based contraceptive should not smoke because smoking increases the risks of dangerous side effects, especially over the age of 35.