No, it's actually a home remedy, and it is time-tested. For centuries, that's what people used to break up a cold. The lemon juice helps with the sore throat and breaks up congestion, the honey helps to coat the throat and ease the cogh response, and the hot water is to make it all fit together.
It's the only thing I've ever taken that has ever really busted up my colds. Of course, I don't get colds any more (or the flu) so drinking one is for pleasure only. NOT!!!
Think of it as hot, sweet lemonade.