When you see football players sniffing their fingers or gloves on the sideline, they’re inhaling smelling salts. Players crush small ammonia capsules and rub the residue on their gloves or fingers so they can take a quick hit of ammonia vapor right before a play, triggering a jolt of alertness and a rush of fight-or-flight energy.
What Smelling Salts Actually Are
Smelling salts are chemical compounds made of ammonium carbonate and sodium carbonate. When you crush or snap the capsule, it releases ammonia gas. That sharp, pungent vapor irritates the membranes inside your nose, which stimulates a nerve called the trigeminal nerve. This triggers a cascade of reflexes: your breathing rate spikes, your heart rate ticks up, and your body shifts into a heightened state of arousal. The whole process takes seconds.
Players don’t always hold a capsule directly to their nose on camera. Instead, many crush the capsule and wipe it across their gloves or fingertips. That way, they can casually bring their hand to their face for a quick sniff without fumbling with a tiny packet while wearing bulky gloves. It looks like they’re just smelling their fingers, but they’re getting a concentrated dose of ammonia right before they step onto the field.
Why Players Use Them
The appeal is simple: ammonia inhalants make you feel explosively awake. Players report feeling a surge of energy, sharpened focus, and a psychological readiness to hit or be hit. Research confirms that ammonia inhalation elevates heart rate, perceived alertness, and what study participants described as “psyched-up energy.”
Whether that translates to actual physical performance is more complicated. A 2022 study of physically active female athletes found that ammonia inhalation significantly increased both peak and mean power output during repeated high-intensity cycling efforts. But in studies measuring a single explosive effort, like a max-effort jump or grip strength test, ammonia didn’t improve any measurable performance markers despite making athletes feel like they performed better. The boost appears to be psychological and respiratory rather than muscular. During repeated bouts of intense exertion, that extra arousal and faster breathing may genuinely help sustain power output. For a single snap or play, it’s more of a mental ignition switch.
The NFL’s 2025 Rule Change
Smelling salts have been a sideline staple for years, but the NFL changed its policy heading into the 2025 season. The league sent a memo to all 32 teams banning club personnel from providing or supplying ammonia inhalants in any form during pregame activities, games, and halftime. That includes ammonia capsules, inhalers, ammonia in a cup, and any variation of smelling salts.
The decision was driven by two concerns. First, the FDA issued a warning in 2024 to companies producing ammonia inhalants, noting there’s no solid evidence supporting the safety or efficacy of these products for improving mental alertness or boosting energy. Second, and more critically for football, ammonia inhalants can mask neurological signs and symptoms of concussion. A player who just took a hard hit to the head might sniff ammonia, feel alert and clearheaded, and return to the field when they shouldn’t. The NFL’s Head, Neck, and Spine Committee recommended the ban specifically because of this risk.
The ban doesn’t mean players can’t use smelling salts at all. The NFL Players Association clarified that the policy restricts clubs from supplying them, not players from using them. Players can still bring their own. The 2025 NFL season is essentially “bring your own smelling salts,” which means you’ll likely still see players sniffing their gloves on the sideline.
How Common the Practice Is
Ammonia inhalant use isn’t limited to a few players. It’s widespread across the NFL and has been for years. You’ll see linemen, linebackers, and defensive backs all doing it, typically in the moments right before kickoff or before returning to the field after sitting out a series. The practice also extends well beyond football. Powerlifters, hockey players, and strongman competitors all use smelling salts before maximal efforts. In football specifically, the ritual of applying ammonia to gloves and sniffing fingers has become so routine that many fans notice it on broadcast without understanding what’s happening.
Risks of Regular Use
Ammonia is a potent irritant. At the concentrations found in commercial smelling salts, a single sniff causes a sharp burning sensation in the nasal passages, which is exactly how the product works. Repeated exposure to ammonia vapor can irritate the lining of the nose and upper airways. For people with asthma, nasal ammonia exposure can trigger reflexive tightening of the airways, potentially worsening breathing rather than improving it.
The more significant concern in football is the concussion-masking problem. Ammonia inhalants create a powerful sensation of alertness that can temporarily override the grogginess, confusion, or disorientation that would otherwise signal a brain injury. A player who uses smelling salts after a big hit may feel fine and pass a quick sideline check, only to be playing through a concussion. This was a central reason the NFL’s medical committee pushed for the 2025 supply ban, even though the league stopped short of prohibiting individual player use entirely.