What smelling salts do in your body

Smelling salts are capsules or vials containing ammonia compounds that release a pungent vapor when crushed or opened. When you inhale that vapor, it irritates the mucous membranes in your nose and throat, triggering an involuntary gasp reflex and a sharp inhalation. This reflex happens because ammonia activates pain receptors (called nociceptors) in your nasal passages, not because the compound enters your bloodstream or changes your brain chemistry.

The gasp reflex causes a sudden increase in breathing rate and heart rate, and briefly raises blood pressure. Your body also releases a small amount of adrenaline in response to the irritation. This is why smelling salts produce an when ready jolt—but the effect is entirely local to your respiratory system and lasts only seconds to a minute.

Smelling salts do not restore consciousness in someone who has fainted or lost awareness. That is a myth from boxing and football sidelines. If someone is unconscious, the ammonia vapor will not wake them because they are not breathing it in deeply enough to trigger the reflex. The only reason to use smelling salts on an unconscious person is if you are trying to stimulate them to breathe more forcefully, which is not the same as waking them up.

Key Takeaways

  • Smelling salts work by irritating nasal membranes and triggering a gasp reflex, not by entering the bloodstream or altering brain function.
  • The effect lasts seconds to a minute and produces a temporary increase in heart rate, breathing, and blood pressure.
  • Smelling salts cannot wake an unconscious person; they only work if someone is already breathing and conscious enough to inhale the vapor.
  • Research on athletic performance shows mixed results, with some studies finding a small boost in strength or power output and others finding no effect.
  • Repeated use or high exposure to ammonia vapor can irritate airways and may trigger asthma symptoms in people with reactive airways.

Why athletes use smelling salts

Smelling salts became popular in contact sports—football, rugby, weightlifting—because the sudden jolt and increased alertness seemed to help athletes perform better in the moments after using them. The theory is that the spike in heart rate, breathing, and adrenaline could enhance strength, power, or reaction time during competition.

Some athletes also report a psychological effect: the ritual of using smelling salts before a play or lift creates a mental trigger that helps them focus or feel more aggressive. This placebo-like effect is real in the sense that it changes how the athlete feels, even if the ammonia itself is not changing their muscle function.

The National Football League (NFL) banned smelling salts in 2013, citing safety concerns. The National Collegiate Athletic Association (NCAA) followed with restrictions in 2014. These bans reflect concern about repeated exposure and the lack of clear evidence that smelling salts improve performance in ways that justify the risks.

What research shows about performance

Human studies on smelling salts and athletic performance are small and produce inconsistent results. A 2013 study published in the Journal of Strength and Conditioning Research found that college football players who used smelling salts before a vertical jump test showed a small increase in jump height compared to a control group. However, other studies have found no difference in strength, power, or sprint performance after smelling salt use.

The quality of evidence is limited because most studies involve only a handful of participants, and it is difficult to control for the placebo effect—athletes who expect smelling salts to help them often do perform better, regardless of whether the ammonia itself is responsible. Animal studies show that ammonia exposure can increase adrenaline and heart rate, but this does not directly translate to improved muscle performance in humans.

The most honest summary is that smelling salts may produce a small, short-lived boost in alertness or aggression, but there is no strong evidence they improve strength, power, or endurance. Any performance gain is likely small and may be driven partly by expectation rather than the chemical effect of ammonia.

Safety concerns with repeated use

Smelling salts are generally safe in single, brief exposures—the irritation resolves quickly once you stop inhaling the vapor. However, repeated or prolonged exposure to ammonia can damage the lining of your airways and lungs. People with asthma, chronic obstructive pulmonary disease (COPD), or other reactive airway conditions are at higher risk for irritation, coughing, and bronchospasm (airway tightening).

Frequent use over weeks or months may lead to chronic irritation of the nasal and throat tissues, and some athletes report persistent coughing or throat sensitivity after heavy smelling salt use. There is also a theoretical risk that repeated ammonia exposure could increase inflammation in the airways, though long-term studies in humans are lacking.

People with heart conditions or high blood pressure should be cautious because smelling salts raise heart rate and blood pressure acutely. If you have a cardiac history, check with your doctor before using them.

How smelling salts differ from other stimulants

Smelling salts are not a drug and do not enter your bloodstream, so they are not subject to the same regulations as stimulants like caffeine or ephedrine. However, they produce a similar effect—a sudden spike in alertness and heart rate—through a different mechanism. Caffeine works by blocking adenosine receptors in the brain; smelling salts work by triggering a reflex in your nose.

Because smelling salts are so short-acting (seconds to a minute), they cannot sustain performance the way caffeine can over an hour or more. They are also less predictable—the strength of the effect depends on how deeply you inhale and how sensitive your nasal membranes are that day.

Other legal performance aids like creatine, beta-alanine, or beetroot juice have stronger evidence for improving strength or endurance, though they work over longer timescales and require consistent use over days or weeks.

Why the NFL and NCAA restricted them

The NFL banned smelling salts in 2013 after several high-profile incidents in which players used them repeatedly during games. The league cited two main concerns: the lack of proven benefit and the potential for misuse or overexposure. Coaches and trainers were using smelling salts on players who were dazed or showing signs of concussion, which raised questions about whether the salts were masking symptoms that should have led to medical evaluation.

The NCAA imposed restrictions in 2014 that allow smelling salts only under specific conditions: a physician or athletic trainer must supervise their use, and they cannot be used on athletes with respiratory conditions or cardiac history. The restrictions also prohibit use on athletes who are confused, disoriented, or showing signs of head injury.

These rules reflect the principle that even a legal substance should not be used in ways that could delay medical care or mask injury. Smelling salts are still legal to own and use in many contexts, but organized sports have decided the risks outweigh the unproven benefits.

Smelling salts and fainting: the myth

One of the most persistent beliefs about smelling salts is that they can revive someone who has fainted or lost consciousness. This is not accurate. Fainting happens when blood flow to the brain drops suddenly, usually because of a drop in blood pressure, a heart rhythm problem, or a neurological event. Smelling salts cannot restore blood flow to the brain.

If someone is unconscious, they are not breathing in the ammonia vapor deeply enough for the gasp reflex to work. Even if they were, the reflex would only increase their breathing rate—it would not address the underlying cause of the fainting. The correct response to fainting is to lay the person flat, elevate their legs, and call for medical help if they do not regain consciousness within a minute or two.

The myth likely persists because smelling salts were used in the early 20th century in medical settings, and people assumed they must have been effective. In reality, they were abandoned by medicine because they do not work for this purpose.

Frequently Asked Questions

Can smelling salts improve my workout performance?

The evidence is weak and mixed. A few small studies show a possible small boost in strength or power, but many others show no effect. Any benefit is likely short-lived (seconds to a minute) and may be driven by expectation rather than the ammonia itself. Stronger evidence supports other approaches like adequate sleep, proper nutrition, and proven supplements like creatine.

Are smelling salts safe to use regularly?

Single, brief exposures are generally safe for people without respiratory or heart conditions. However, repeated use over weeks or months can irritate your airways and may trigger coughing or asthma symptoms. If you have asthma, COPD, or heart disease, talk to your doctor before using them.

Will smelling salts wake someone who has fainted?

No. Fainting is caused by a drop in blood flow to the brain, and smelling salts cannot restore that blood flow. If someone is unconscious, lay them flat, elevate their legs, and call for medical help if they do not wake within a minute or two.

Why did the NFL ban smelling salts?

The NFL banned them in 2013 because there was no clear evidence they improved performance and because coaches were using them on dazed or injured players, potentially masking symptoms that needed medical attention. The NCAA followed with restrictions in 2014.

How long does the effect of smelling salts last?

The effect lasts only seconds to about a minute. Your heart rate and breathing return to normal quickly once you stop inhaling the vapor. This short duration is one reason the evidence for performance benefit is weak—any effect is too brief to influence most athletic movements.