With all the news surrounding Caitlyn Jenner’s transition, many around the world are wondering what kind of process someone undergoes to redefine their gender. One of the tools is hormone therapy, a system for switching the body’s production of hormones to the hormones of a preferred gender.

Fortunately, the good folks over at the Reactions YouTube channel have put together this informative video breaking down the chemical changes that occur within the body during hormone therapy in gender transition.