For years, Jonathan Reilly, a 41-year-old biomedical engineer based in Los Angeles, would start his workday in a fog. "I'd come into my office feeling like I had woken up at four to take someone to the airport," he says. "It took me twice as long to accomplish anything important." But now he walks into his regular 8 a.m. meetings with crystal-clear focus and enough energy to drive through an intense 12-hour day at the office. Plus, he's always in a good mood.

Reilly isn't high or wired on caffeine—he's taking a pill called Nuvigil. "It's made me feel awake for the first time," he says. "I don't mean 'awake' like going to Burning Man and taking acid, or being on speed, where you just think you're smarter. I'm much more creative and much more productive. If I'm project- managing, it's like seeing the matrix. It makes it easier to put the pieces together to come up with a complete picture."

In lieu of Adderall and eight-balls, hard-charging professionals are turning to a new class of nootropics (a type of smart drug) to score an edge at work. It's a category of substances that includes prescription analeptics like Nuvigil and Provigil, as well as less-potent supplements like New Mood and Alpha Brain (both are sold on for around $30 a jar) that are made of vitamins, amino acids, and antioxidants, which purportedly stimulate your brain receptors. Devotees say nootropics are a wholly different experience from energy drinks, as they give you a mental edge, increasing memory, intelligence, motivation, and concentration—without the jitters or crashes that can come with stimulants.

"These drugs are being used in industries where there's less room for failure and immediate results are expected," says Roy Cohen, a career coach in New York City and the author of The Wall Street Professional's Survival Guide. "These people thrive on accomplishment—it's in their DNA. It's incredibly seductive to have this potential for guaranteed peak performance."

Joe (not his real name), 26, a banking consultant in Chicago, started taking Alpha Brain while getting his M.B.A. and continued to use it as a study aid before his CPA exam. "I'd retain more information than I would if I hadn't taken it," he says. Alpha Brain's still his go-to before presentations, which used to make him nervous. "It gives me confidence," he says. "I feel like I'm working on my optimal levels while I'm on it." (His brother, a lawyer, agrees. "My brain feels a little cleaner," he says.)

That clarity is key, say users, who feel like they're actually doing something good for their mind, as opposed to simply getting hopped-up so they can push through another all-nighter. And while most of these guys would rather not skip a dose, they say they can miss a day with no ill effects.

Many users have found that their physicians will prescribe Provigil or Nuvigil if they contrive complaints of frequent jet lag or excessive fatigue. But those with less-flexible doctors have better luck online—although it's illegal, you can order a month's supply of these drugs for about $90 (usually imported from India).

So have these guys actually found a magic pill? Emily Deans, a psychiatrist in private practice outside Boston, cautions that, in high enough doses, smart drugs may affect your temperature, heart rate, and blood pressure and advises seeking a prescription. Supplements, unlike prescription- or pharmaceutical-grade drugs, can be prepared with varying amounts of active ingredients—meaning two pills from one jar may be three times the strength of two of the same pills from a different jar. Deans says to be especially careful of the plant-derived supplements that contain Huperzine A (as Alpha Brain does). "This ingredient can make you more alert or sharpen thinking," she says, "but if you take too much at once, you can make yourself psychotic."

Even Deans admits, though, that some guys could benefit from brain drugs. "I don't know if it's ethical to recommend, but for students using it to study or surgeons trying to stay up all night long, a [prescription nootropic] might be useful," she says. "If they were willing to not burn the candle at both ends for too long, it might help people do a better job."

For four months, when he couldn't get a prescription, Reilly missed Nuvigil's effects. "I was getting up later in the day and getting less done," he says. He recently started taking it again. "I enjoyed the person I was more when I was taking it, so I decided this is something that should be part of my life."

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Smart Drugs Available in the Vitamin Aisle

These common vitamin-store supplements are nootropics, too, according to nutritionist Rania Batayneh, author of The 1:1:1 Diet.

The supplement: DHA, an omega-3 fatty acid found in fish and seaweed.
The payoff: Improves memory by strengthening communication between brain cells.

The supplement: Passionflower, a flowering vine.
The payoff: Promotes relaxation by reducing blood pressure.

The supplement: Turmeric, a spice used in mustards and curries.
The payoff: Reduces performance anxiety by curbing the stress hormone cortisol.

The supplement: Theanine, an amino acid found in green tea.
The payoff: Helps with focus by upping dopamine levels.

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5 Ways to Train Your Brain

Drug-averse? You can keep your mind agile with games instead. Science long held that the brain couldn't grow new cells, but that's been proved wrong. You can continue to create them and connect them until the day you die, upping memory, clarity, and perhaps intelligence. "But you have to force the brain to grow," says Cheryl Deep of the Brain Neurobics program at Detroit's Wayne State University. Try these simple mental exercises.

1. Use your computer mouse with your nondominant hand.
2. Turn the analog clock you use the most upside down.
3. Wear your watch on the opposite wrist (up the cognitive boost by turning it upside down, too).
4. Avoid the word the in a conversation.
5. Chew gum (FYI: The brain stimulation lasts only while you're chewing).

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