Most authorities do not require kosher certification, for Pesach or year-round use, on non-chewable pills so long as they do not have a flavored coating. In this case, they are halachically inedible and not a concern.
Some chewable or coated pills contain chametz, and cannot be used on Pesach. This issue is discussed at length on the OU site:
http://www.oukosher.org/passover/articles/medication-guidelines-for-passover. An extensive list of medications (and contraceptives) which are kosher for Pesach is available at:
http://www.clalit.co.il/he/medical/pharmacy/pages/medicaments_kosher_for_passover.aspx. The list uses the accepted names for these medications in Israel.
Should one's medication be found not to be Kosher for Pesach, one should consult with one's physician in advance as to how to handle the situation. One cannot simply stop taking contraceptive pills as this will lead to withdrawal bleeding and potentially make pregnancy possible. However, it may be possible to find a Kosher for Pesach alternative. If not, then a rav should be consulted as to how to handle the situation.
