MIAMI (CBSMiami) — A narcolepsy drug, dubbed the “Viagra for the brain”, is being used by some people to increase their brain function.

Although the primary function of FDA-approved Provigil and its newer version Nuvigil, is to treat sleeping disorders and improve wakefulness, some people take the pill because they’re simply tired and want more energy.

Dave Asprey, the VP of a billion dollar internet security firm and the CEO of The Bulletproof Executive, said he was given a prescription for the pill nine years ago and it’s changed his life.

“This is the sort of thing that lets you perform at levels you didn’t know you were capable of,” he said. “You have a laser-like focus you didn’t have before.”

“Their primary function is to wake you up, Make you more awake and functional throughout the daytime,” according to sleep specialist Dr. Ron Popper. Dr. Popper  said users of the medication need to be careful because it hasn’t been approved by the FDA for brain boosting or fatigue alone.

“Until the studies are done to show the long-term effectiveness and long-term potential side effects, it should be used according to the FDA guidelines,” he said.

Dr. Popper said the drug should only be prescribed for adults with conditions such as narcolepsy, obstructive sleep apnea, and shift worker sleep disorder.

Asprey said he was prescribed the drug for shift worker sleep disorder and it even helped him lose weight.

“When I started this I weighed 300 pounds, more than 10-years ago. This was huge boost in my mental performance.  It was like wow I’m awake!”

He thinks people will benefit from “smart drugs” because he has.

“I’m really convinced that when people take it for a while, they get used to operating at a higher level performance. Even without the drug, they maintain the ability to focus,” Asprey said. “This is the sort of thing that lets you perform at levels that maybe you didn’t know you were capable of.”

Off label use of these drugs, to make you smarter, more focused, and possibly lose weight, has sent sales skyrocketing and nicknames proliferating.

“I’ve heard Viagra for the Brain. Is it? Yeah and Viagra was terribly abused as well,” said Dr. Popper.

Even though the drug doesn’t stimulate the entire central nervous system like “speed” or Ritalin, there are no studies into how the use of this drug affects the brain over time.

Known side effects include headaches, back pain, mouth sores, anxiety, serious rashes, dizziness, vomiting, irregular heartbeat and thoughts of suicide.

“If we could find a magic pill with no side effects that did only what it was intended to do, I would say great, sign me up and give it to me too. But this is not a magic pill. It has potential side effects, it has potential abuse and addictive potential and we’re seeing that. Too much of anything isn’t good,” said Dr. Popper.

Even Asprey, who downs dozens of vitamins with every meal, insists a good nights sleep, exercise and a good cup of coffee can yield the same productive results.

“This stuff is pretty amazing. That said if I had to give up high quality coffee versus Provigil, I think I’d stick with my high quality coffee. But the combination is one that gives me the perfect edge in order to get things done,” said Asprey.

A lot of people use this drug in secret, including many college and high school students. But the drug is absolutely not for use for any condition in children under 18.  It is also extremely dangerous to take along with sleep aides.

Provigil is now available as a generic.

Nuvigil costs around $350 a month and you will need a doctor’s prescription.