“It works in a very select area of the brain called the hypothalamus, which regulates among other things sleep and wakefulness,” Wyatt said. “And because it doesn’t work in widespread areas of the brain, it seems to have a much cleaner side-effect profile, not producing nervousness or tremulousness or shakiness that other stimulants can.”

There are some side effects, including headaches, nausea, infection, possible nervousness, anxiety and insomnia. But patients would see a limited number of those effects at one time, and they are actually less than the effects of caffeine.

Dodds thought that the pill would have effects similar to caffeine, but she was surprised.

“I thought, OK, it’s going to be like 10 cups of coffee,” Dodds said. “It wasn’t at all. I was really surprised. I wasn’t tired. I mean, I felt tired like I had been working, but not like OK, it’s halfway through, I’m almost there, I can almost sleep. It wasn’t a radical improvement, but I just felt good, like you had slept all night and were up during the day.”

Johnson said that there are legitimate uses of the drug, for people who are chronically on late shifts, and for patients with multiple sclerosis, who suffer from fatigue as a result.

“But I do think a broad use would be unethical for social reasons,” Johnson said. “I personally would feel uncomfortable prescribing the drug to just anyone. We just don’t know completely how it works, and we have limited experience with knowing what happens after long-term use.”