Johnny Depp snorts cake ingredients instead of cocaine in "Blow." While watching films such as "Scarface," "Blow," "Boogie Nights," "Traffic" or "Pineapple Express," do you ever wonder what the actors on-screen are actually snorting, smoking or drinking, take after take?

Most of the time, it's not the actual substances—unless your name is Nicolas Cage—who once told reporters he snorted doctor-approved cocaine to prepare for his role in "Bad Lieutenant: Port of Call - New Orleans."

Instead, Hollywood prop masters have a few tricks up their sleeves.

Often, actors are simply snorting ingredients usually used to bake a cake and special stores have devoted their business to legal, herbal bud used on film sets.

On Showtime's "Weeds," the herbal tobacco makes the actors feel a little lightheaded, says the show's executive producer Roberto Benabib.

"According to them, it gets them higher than regular marijuana. They end up smoking so much of it they get very lightheaded and they don't like it. Sometimes they do take after take and you will see them getting woozy because it has a strange effect on them. But it's totally legal and it is what we are supposed to use."