Millions of Americans take millions of sleeping pills every year, a sign, experts say, that human beings weren’t designed to live in a wired world of constant stimulation.

All those highly addictive pills, meanwhile, have potentially serious side effects. So the Food and Drug Administration stepped up with a warning.

“Rare but serious injuries have happened with certain common prescription insomnia medicines,” the agency said, including while people are “sleepwalking, sleep driving, and engaging in other activities while not fully awake.”

The FDA is now requiring that the most commonly prescribed sleeping pills carry a notice that these meds may be more dangerous than people realize. It singled out Ambien, Lunesta and Sonata as being particularly worrisome.

How serious is the problem? Government researchers found 66 cases of “complex sleep behaviors occurring with these medicines over the past 26 years that resulted in serious injuries, including death,” the agency said.

“These cases included accidental overdoses, falls, burns, near drowning, exposure to extreme cold temperatures leading to loss of limb, carbon monoxide poisoning, drowning, hypothermia, motor vehicle collisions with the patient driving, and self-injuries such as gunshot wounds and apparent suicide attempts,” it said.

“Patients usually did not remember these events.”

All because we can’t get enough shut-eye.

Jerome Siegel, a sleep researcher at UCLA, said there’s no question we’re overdoing it with use of powerful chemicals to knock ourselves into a stupor. “There are situations where short-term use of sleeping pills might be helpful,” he said. “But even that’s debatable. If you ask me, no one should be taking sleeping pills.”

Every sleep expert I spoke with said pretty much the same.

“There is evidence that sleep medications are over-prescribed, and that not enough attention is paid to the side effects in many cases or alternative approaches,” said Bryce Mander, assistant professor of psychiatry and human behavior at UC Irvine.

According to the Centers for Disease Control and Prevention, as many as 70 million Americans “suffer from sleep disorders or deprivation.”

An estimated 4% of U.S. adults are taking prescription meds to help them sleep at any given time, the CDC says. That’s 10 million people.

They’re spending roughly $2 billion a year, with millions of dollars more going toward over-the-counter drugs and dietary supplements such as melatonin.

Needless to say, this is a golden opportunity for drug companies, which have built multimillion-dollar marketing campaigns around the notion that everyone deserves a decent night’s rest.

“Sleep is big business in the United States,” said Raj Dasgupta, a USC sleep researcher. TV ads for sleeping pills are effective, he said, because “people are always looking for a shortcut.”

UCLA’s Siegel advised taking control of your sleep pattern by getting up at the same time every day, even on weekends.

Yes, that can leave you a little groggy if you went to bed late, or had trouble falling asleep, the night before. Over the long haul, however, your body will adjust to the regular schedule and will develop a cycle that delivers seven or eight hours of downtime.

As for sleeping pills, the FDA says you should contact your doctor right away “if you do not remember activities you have done while taking the medicine.”