Add Yahoo as a preferred source to see more of our stories on Google. Testosterone is the main sex hormone in men. It’s best known for its role in the development of male sexual characteristics and ...

While a plummeting hormone level can trigger depression and irritability, experts say a modest decline can make men more ...

This article was reviewed by Felix Gussone, MD. If you’ve been feeling a bit more couch potato than go-getter lately, dragging through the day, snapping at people for no reason, or wondering where ...