What is this "Tiger Blood" Charlie Sheen is going on about?

Normally I don’t usually care what celebrities do….But a friend sent me Charlie’s “winning” song and in it “he has Tiger Blood”, so I looked at a few other wants he did, he mentions it in a lot of them and in some he has a bottle marked with red liquid….

Is Tiger Blood a real thing? Brand name of some sort of protein drink

Or is it just something he made up….?