June 10, 2011 -- What could be easier than putting a red stamp-sized gel strip on your tongue, letting it dissolve and getting a quick energy jolt? No waiting in line at Starbucks, no alcohol-laden Four Loko, just a straight shot of caffeine; the equivalent of about one cup of coffee.
For most adults, who are used to caffeine, nothing could be simpler, experts say.
Sheets, made by Purebrands, is promoted as "0 calories. 0 sugar. B vitamins. Fast acting. The new way to do energy." And "zero crash," as one strip contains about 50 milligrams of caffeine.
But when this latest energy kick gets in the hands of children or already-wired teens, it has the potential for abuse.
Teens already consume too many daily doses of caffeine, from the morning Joe to cokes and energy drinks that can cause palpitations, anxiety and sleep disturbances, just at the age when they need their sleep for growth, experts say.
"It's a really bad idea," said Rosalind Cartwright, professor emeriti in neurological sciences in the Graduate College at Rush University Medical Center. "One hundred milligrams is not that much. But if used repeatedly, it can cause all kinds of trouble.
"It will give them a jolt and somewhat better focus and attention for a short while, but it has a pretty steep dropoff, and if you keep taking it, you get enormously sleepy afterwards."
The Florida-based company launched a $10 million promotional campaign in May with TV ads featuring star athletes and posted a billboard in Times Square.
Purebrands CEO Warren Struhl was unavailable for an interview but told ABCNews.com in an email that, "Sheets has been very clear on their packaging in terms of discouraging usage by kids under 12."
But caffeine can be hazardous for any age in teens who are sensitive or those with heart conditions or attention-deficit disorder.
The American Academy of Pediatrics issued a report this month recommending that teens and children avoid energy and sports drinks, which carry no benefit and some risk. That includes all caffeinated drinks, including colas and coffee.
Caffeine in High Doses Can Be Hazardous
"Caffeine is very safe; it's used in newborns to increase arousal," said John Herman, professor in sleep medicine at University of Texas Southwestern Medical Center in Dallas.
"But nothing should be packaged that could appeal to children," Herman said. "It should specify dosage and instructions on how to use it and what is the maximum. A high dose of anything -- sugar or salt -- becomes harmful.
"If it's red-colored and it's sweet, kids might take three, four or five of them and go into an anxiety attack and palpitations," he said. "Kids get anxious when they take caffeine and it could put them over the top."
Even one cup of coffee in the morning can affect sleep, which can be more fragmented and lead to early morning awakening, Herman said.
Caffeine intake is growing among children at younger ages, but there are no long-term studies on its effect on child development, according to James W. Wyatt, a clinical psychologist at the Clinic for Sleep Disorders at Rush University.
Teenagers need eight to nine hours of sleep a night so they can "learn optimally," he said. "Everything from attention, concentration, memory and social skills ... they all rely on an alert brain."
Repeated sleep loss can compromise the immune system.
Rush University sleep expert Cartwright said high doses of caffeine can even cause dangerous sleep aberrations.
"When you get over their threshold of response, you get rebound sleep that is like a narcolepsy attack and it's very scary for them and for anyone trying to wake them out of it," she said.
In some severe cases, Cartwright said such fatigue can result in a dangerous half-awake, half-asleep state where the brain plays a tug-of-war with itself. A 2011 study published in the journal Nature described a similar state in rats.
"You get up and walk, but the brain is not fully awake," she said. "There are enough cases of sleep walkers in the literature who took an enormous amount of caffeine during the day and into the night."
Cartwright defended a court case in 2008 where a man walked into the bedroom of a neighbor's sleeping teenager and boyfriend while the accused was asleep.
"He was caffeine loaded," Cartwright said. "But we don't know who's vulnerable and who's not."
Caffeine Sends Airman to Hospital
Cary Houghton Anderson, a 33-year-old mother of two from Oak Harbor, Wash., rushed her husband, Cody, to an urgent-care clinic after he took a caffeine-based energy powder that delivered 100 milligrams of caffeine. The Navy air crewman mixed it with water before going to the gym to improve his endurance.
But hours later, he was flushed, lost his equilibrium and became nauseated. "He lay down on the couch, not asleep, but acting comatose and that night it really kicked in and he needed a bucket by the side of his bed," his wife said.
The next day at the clinic, doctors found his blood pressure was elevated. "They said it was too much caffeine," Anderson said.
She worries that caffeine in a fun, red-colored strip might be a danger to her two mischievous children, ages 3 and 5.
"Oh, my goodness," Anderson said. "Those boys would think it was candy. We had a package of Dum Dums [candy] and I have caught them climbing on top of the counter trying to reach them in the cabinet.
"I can just imagine if they thought it was gum," she said. "They rip off my purse for their little sugar friends and hide under the bed and chew it. I am certain if I was taking something like [Sheets] they would definitely think it was candy. It would be nasty."
And as for her husband's caffeine incident and the ever growing selection of energy products, Anderson said, "Scary stuff. When did the morning coffee not give you a jolt?"