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One whiff and Ezekiel Elliott's eyelids begin to flutter, his mouth falls oddly agape and his pupils roll back in his head. It's Week 4 of the NFL season, and kickoff is just moments away inside AT&T Stadium, where Elliott and a handful of his Cowboys teammates are breathlessly engaged in the latest, strangest sports ritual: huffing the stomach-turning noxious fumes found in smelling salts.

The ammonia-based inhalant is manufactured for the express purpose of treating or preventing fainting, but at some point, NFL players and other athletes discovered they could repurpose the decongestant properties and adrenaline-pumping side effects into a perfectly legal, low-tech pick-me-up ... even though there's zero proof of any performance benefit. In fact, this will be the first of at least eight capsules for Elliott today. Using hand movements reminiscent of his trademark "feed me" gesture, Elliott inhales a capsule before donning his helmet for each Dallas drive in a 35-30 loss to the Rams. He's far from alone, on either team. Directly behind Elliott, two members of the Cowboys' game-day staff, dressed in matching blue slacks and white polos, are busy sniffing away on their own ammonia capsules. Just a few minutes into the game, the Cowboys have discarded so many capsules that the area in front of their bench looks like the floor of a kid's bedroom after trick-or-treating. (Don't change the Cowboys' moniker to Ammonia's Team just yet. There are dozens of discarded smelling salts capsules on the Rams' sideline too.)

Near the end of the first half, six members of the Dallas defense can be seen simultaneously hitting the salts before taking the field. The group includes veteran cornerback Orlando Scandrick, who jogs onto the field while using his right hand to make the sign of the cross and his left hand to sniff salts, and defensive end Demarcus Lawrence, the NFL's sack leader through four games.

Lawrence says he can't drink coffee for a quick jolt during the game because it might affect his stomach, so he has turned to smelling salts. "The ammonia wakes you up, opens your eyes," Lawrence explains. "You'll be on the bench, you start to get a little tired and you got to wake your body up, and that's what that little ammonia does for you."

But that simple explanation, like the entire smelling salts fad itself, doesn't quite pass the sniff test.

ONCE PRESCRIBED to Victorian-era women plagued by fainting spells, ammonia inhalants are now manufactured in single-use capsules the size of a small stick of gum. Each sealed white plastic wrapper contains a .3-milliliter mix of alcohol (35 percent), ammonia (15 percent), water, oils and red dye that, when crushed between two fingers, stains the wrapper a telltale pink. Aerated by the alcohol, the ammonia fumes pack such a rancid punch -- imagine military-grade concentrations of Windex, wasabi and Vicks VapoRub that get T-shirt-cannoned up both nostrils -- that most users instinctively snap their heads back to escape the stench.

The initial discomfort is quickly followed by a sensation that your breathing pathways have not just opened up but expanded exponentially while ramping up your alertness to an almost euphoric level. This phase is short-lived, however: Lawrence says that for him, it lasts about one set of downs. Also, the initial wave can sometimes be followed by prolonged bouts of nausea that serve as a vivid reminder of why household ammonia products come with the warning: Avoid inhalation of vapors.

"The claim is that smelling salts arouse your consciousness and focus, but how many of us in our daily lives think it's appropriate during a tough day at work to open a bottle of ammonia and start sniffing the fumes?" says Dr. Joseph Estwanik, a fellow with the American College of Sports Medicine. "Ammonia's intended use is for cleaning. Giving a highly trained elite athlete ammonia to help them perform at their peak is like throwing a drowning man a cup of coffee."

The company that manufactures the NFL's capsules, the New Jersey-based James Alexander Corp., has repeatedly stated that the product is designed to treat or prevent fainting. A company spokeswoman had no response when asked about the widespread misuse of smelling salts in the NFL. Ignoring the topic seems to be the common response when it comes to the league's secret little helper. Even though the capsules are typically distributed by athletic trainers, the National Athletic Trainers' Association wouldn't discuss the topic and doesn't have official guidelines on the use of ammonia capsules.

There is one clear, though indirect, danger to using smelling salts: In the past, they've been routinely used to mask and combat concussion symptoms in sports such as boxing and football. In 2011, after quarterback Terry Bradshaw began experiencing the effects of brain damage suffered during his Hall of Fame career in Pittsburgh, he wrote: "When I played for the Steelers and I got my bell rung, I'd take smelling salts and go right back out there. All of us did that."

For that reason, the practice of using salts has been banned for decades by major boxing organizations, and in the NFL, league spokesman Brian McCarthy says "team medical staffs do not use [smelling salts] in any way for the treatment of any concussion or other injury.

"We have seen no proven performance enhancement and minimal risk," he says. "Team medical staffs monitor all aspects of their players' care."

In college football, salts are already common. And Estwanik wants the NFL to outlaw ammonia before the league's huffing habit becomes just as widespread on the high school level, where there isn't enough medical supervision to prevent the use of ammonia to mask conditions such as asthma, dehydration and head injuries.