Did Michael Jackson take medicine to turn white?

Michael Jackson's skin was white because he had a rare skin condition called vitiligo.

Vitiligo is an inherited genetic disorder. It is a condition when you lose melanocytes (cells that give color to the skin). It results in smooth, white patches in the midst of normally pigmented skin. In the case of African-Americans, this discoloration is very prominent, although any age, sex and race can suffer from it.

Michael did not take medicine to turn white obviously. He took makeup to cover up the white blotches on his skin. Soon, the skin on his body had become dominantly white which forced him to start using a whiter makeup instead of darker tone. He did although do something that eventually evened out his skin tone.