using l-dopa from fava to extend l-dopa from sinemet? c'mon, think about it. are you chewing willow bark to get acetylsalicylic acid, aspirin?
http://inventors.about.com/library/i.../blaspirin.htm

just had to say something, sorry if rude. but "natural" imho is no different than synthetic with l-dopa, both are made by chemical processes from smaller components.
even fava can in rare occasion be dangerous
http://www.associatedcontent.com/art...se.html?cat=25
http://www.ansci.cornell.edu/plants/...ts/vicine.html

Yes, you are right on all counts....but lots of folk blend in a little mucuna or fava with the chemical-type of levodopa (sinemet) and if it makes it work better, longer, faster....whether placebo or not, it's still an improvement in my way of thinking. Like Dumbledore said in the last Harry Potter book, when Harry asked if what he was seeing was all in his head, Dumbledore said "Of course it is...but that doesn't make it any less real..." If one thinks he/she feels better doing this or that, then that works for me. Now if only they could bottle placebo, that would be the ultimate, yes?

Love your cynicism, I'll let you know if/how fava bean juice helps.