In "oceans 13" Matt Damon's character uses a chemical aphrodisiac to bed the cougar, does something like this actually exist?
Hey- this is an interesting question, by the way.
Well, chemical aphrodisiac's do exist. Bremelanotide (PT-141) was the first one that worked- on rats. I'm not sure how effective it, or the other ones, for that matter, are- hey, don't ask me, I don't use it, lol. But I do know that they can affect the central nervous system, by altering neurotransmitters/passages/etc., so that the brain "turns on" the more erotic portions of yourself.
I doubt anything exists that's as strong as the Gilroy, though. At best, these things are superficial and very temporary. There are also aphrodisiacs in nature, supposedly- i.e. Ginseng, the best known one. You could google that, if you're really interested. But again, they're not that strong.
So, in conclusion, yes, they exist, but not like Hollywood presented it. I suppose if someone covered him/herself in the stuff and had his/her partner eat a bunch of herbs or something, then the change might be noticeable. But otherwise, well, getting laid will have to be done traditionally.