While erectile dysfunction drugs affect nitric oxide levels, they do have some side effects. "There are issues with some of the heart drugs folks may be on," Dr. Oz says. "And [men] ought not to use it for recreational purposes—because if everything's working down there, it's only going to be a placebo effect. And you're not going to get a bigger or a harder erection by taking it."
But is there any way to prevent problems like that before they start?
One thing that can help keep your body working is garlic, due to a chemical called allicin, which works only when it's raw. "You need something that's an antidote to [the garlic]. So parsley, for those of you who are going to try this, will actually block some of that taste," Dr. Oz says. "Because otherwise you're not going to be close enough to anybody to figure out if it makes a difference."