It's probably in there because the benefits are supported by plenty of research.
Market research which says that those ingredients will more easily allow them to jam more buzzwords onto the packaging, and get more people to buy it.
Or simply, "ooOOOOoohhh, this one has menthol and caffeine! The other ones don't have those things, so this one's got to be better!"
(Sorry, I'm allergic to marketing.)
"Homeopathy is what happened when snake oil salesmen discovered that water is cheaper than snake oil."
's is not the universal way of making anything plural.