What Do Smelling Salts Do for You? A Complete Guide to Their Effects

Smelling salts are ammonia-based compounds that, when inhaled, trigger a sharp inhalation reflex and temporarily increase alertness. They work by releasing ammonia gas that irritates the mucous membranes of the nose and lungs, causing the muscles that control breathing to work faster. This reflex can reverse a faint or give a short-lived boost of wakefulness, which is why athletes and medical responders have used them for years.

How Smelling Salts Work in the Body

The active ingredient in most modern smelling salts is ammonium carbonate, a crystalline solid that partly breaks down into ammonia (NH₃), carbon dioxide, and water vapor when exposed to air Wikipedia. When you hold an opened capsule or bottle near your nose, the ammonia gas irritates the sensitive lining of your nasal passages and lungs.

The Inhalation Reflex

Your body responds to that irritation by forcing a rapid, deep breath. This inhalation reflex is controlled by the same nerve pathways that handle sudden irritants. It overrides your normal breathing rhythm and pulls in more air, which can be enough to wake someone who has fainted.

Fainting often happens when the vagus nerve slows the heart rate too much, reducing blood flow to the brain. The ammonia’s irritant effect stimulates the sympathetic nervous system, which speeds the heart back up and restores blood pressure Mayo Clinic. That is why smelling salts have been used since Roman times to revive people who have lost consciousness.

The ammonia gas does not enter the bloodstream in meaningful amounts. It works entirely through irritation of the trigeminal nerve endings in the nasal mucosa. When that nerve detects ammonia, it signals the brainstem to increase the rate and depth of breathing. This is the same reflex that makes you cough or sneeze when you inhale a strong irritant like pepper or smoke.

Duration of the Effect

The alertness you get from smelling salts lasts only a minute or two. It is not a performance enhancer that builds up over time. The effect is a brief jolt, not a sustained energy boost. Users typically feel a burning sensation in the nose, watery eyes, and a sudden urge to breathe deeply, followed by a rapid return to normal.

Common Uses of Smelling Salts

Smelling salts have two main uses in modern settings: reviving someone who has fainted and providing a short stimulant effect in sports.

Revival After Fainting

Historically, smelling salts were carried by constables in Victorian Britain and kept in first aid boxes during World War II Wikipedia. Today, they are still used in some medical and first-aid settings to help someone regain consciousness after a simple faint. The reflex inhalation increases oxygen intake and can bring a person around quickly.

The recommended distance for use is 10 to 15 centimeters (about 4 to 6 inches) from the nostril. Holding the capsule closer can burn the nasal or oral mucosa. If the person does not wake up quickly, the cause may be more serious than a simple faint, and emergency medical care is needed.

Use in Sports

Athletes in powerlifting, strongman, rugby, and ice hockey sometimes use smelling salts before a lift or a play to sharpen focus and increase alertness. The practice is common in weightlifting because the sudden deep breath and sympathetic activation can help with a heavy one-rep max attempt.

However, governing bodies in boxing and other combat sports have banned smelling salts because they can mask the symptoms of a concussion. The National Football League banned teams from providing smelling salts to players in 2025, though players could still use them on their own Wikipedia.

Risks and Safety Considerations

Smelling salts are not harmless. They carry real risks, especially when used incorrectly or too often.

Physical Harm

Ammonia gas is toxic at high concentrations. Inhaling it too close to the nose can burn the lining of the nostrils, mouth, and throat. Prolonged exposure to large amounts of ammonia can cause lung damage and can be fatal MedlinePlus. The product is meant for brief, occasional use only.

Masking Serious Injuries

The biggest concern in sports is that smelling salts can hide the signs of a concussion or other head injury. A player who is dazed from a hit might appear more alert after using smelling salts, but the underlying brain injury is still there. This can delay proper medical evaluation and increase the risk of a second injury. The American Academy of Neurology and other medical groups recommend against using smelling salts on athletes who may have a concussion NIH.

Neck Injury Risk

The irritant nature of the ammonia can cause a person to jerk their head back suddenly. If that person has an undiagnosed cervical spine injury, the reflex withdrawal can make the injury worse. Holding the salts at the correct distance (10 to 15 centimeters) reduces this risk but does not eliminate it.

Who Should Not Use Them

Smelling salts should never be used on someone who has not been breathing normally, because the reflex inhalation depends on an already functioning respiratory system. If a person is unconscious and not breathing, the priority is CPR and emergency medical care, not smelling salts. People with asthma or other chronic lung conditions may react poorly to ammonia inhalation. The irritant can trigger bronchospasm or worsen existing breathing difficulties.

Proper Administration Technique

To use smelling salts correctly, hold the opened capsule or bottle about 10 to 15 centimeters (4 to 6 inches) from the person’s nose. Wave it gently under one nostril for one to two seconds. Do not hold it directly against the nose or force the person to inhale deeply.

If the person does not respond within 15 to 30 seconds, do not administer a second dose. Lack of response may indicate a more serious condition such as a concussion, stroke, or seizure. The person should be evaluated by a medical professional.

For self-administration, the same distance applies. Take one quick sniff, then set the capsule aside. The effect is immediate, so there is no benefit to holding it longer or sniffing repeatedly. If you feel burning or pain in your nose or throat, you held it too close.

Key Takeaways

• Smelling salts release ammonia gas that irritates the nose and lungs, triggering a rapid deep breath and a temporary increase in heart rate and alertness.
• They are used to revive someone who has fainted and as a short stimulant before athletic efforts, but the effect lasts only a minute or two.
• Hold the capsule 10 to 15 centimeters from the nostril for one to two seconds to reduce the risk of burns to the nasal passages.
• Smelling salts can mask concussion symptoms and delay proper medical assessment, which is why they are banned in some sports and discouraged by medical experts.
• Do not use them on someone who is not breathing, on people with respiratory conditions, or repeatedly as a training aid.
• If the person does not respond within 30 seconds, seek emergency medical help.