Do painkillers such as tylenol or advil require kosher certification?
What about vitamins?
In general, it is always preferable to have a hechsher for medicines and drugs, because one cannot know what is added to vitamins.
However, for vitamins/minerals that are certified as purely of plant origin, one can be lenient where no hechsher/kashrus list is available.
Tylenol and Advil are fine.