Smelling Salt – Uses, Benefits, and Side Effects

People have used smelling salts for hundreds of years to revive someone who has fainted or passed out. Today, some professional athletes believe smelling salts can improve performance.

Smelling salts are inhaled stimulants that increase breathing and blood flow to the brain. Despite their history of use, there is limited research into the effects of smelling salts.

What are smelling salts?

Smelling salts are restorative stimulants.

  • They are a mixture of ammonium carbonate and perfume.
  • However, diluted ammonia mixed with water and alcohol is more likely to be found in today’s smelling salts.
  • The base is ammonium carbonate, a salt with a white crystalline structure. When ammonium carbonate is mixed with water, it releases “aromatic spirits of ammonia,” and the reaction creates fumes that rise from the salts.

How do smelling salts work?

Smelling salts are used to arouse consciousness because the release of ammonia (NH3) gas that accompanies their use irritates the membranes of the nose and lungs, and thereby triggers an inhalation reflex. This reflex alters the pattern of breathing, resulting in improved respiratory flow rates and possibly alertness.


Are smelling salts likely to work for a sport‐related mild head injury?

 It is unlikely that the induced inhalational reflex has a significant therapeutic effect over and above the natural history of the condition. Increasing the respiratory rate alone certainly has no beneficial pathophysiological effect on the nature or underlying cause of concussive injury. Whether the salts increase alertness or improve reaction times or have other positive cognitive benefits remains to be proven scientifically.

Physicians have explained the action of smelling salts as a form of a chain reaction that starts with deeper breathing.

  • The faster breathing rate elevates the heart rate so that the oxygen and carbon dioxide levels can be maintained correctly.
  • This activates the sympathetic nervous system that controls the fight-or-flight response that takes over during emergency situations.
  • The entire chain of events can increase the overall strength of a person or an athlete, although it reduces fine motor skills to some extent.
  • If players feel more confident after inhaling smelling salts, it will positively impact their performance.

Ammonia in smelling salts irritates a person’s nasal and lung membranes when they sniff it. The result is that the person inhales involuntarily and begins to breathe more quickly, which sends more oxygen to the brain.

Do smelling salts cause injury?

While there are numerous case reports of the toxicity of ammoniacal agents when ingested in large doses or inhaled in high concentrations for prolonged periods there are, in fact, no reports of adverse health problems related to the use of smelling salts in sport.

The product information for commercially available smelling salts clearly recommends that the capsule or solution be held 10–15 cm away from the patient’s nose. This is designed to limit any direct burning effect on the nasal or oral mucosa from high concentrations of inhaled ammonia. 

Commercial ammonia inhalation products typically contain 50–100 parts per million (ppm) ammonia.

Most people can tolerate exposure to around 250 ppm of ammonia for under 1 hour. However, even exposure to 50 ppm of ammonia for more than 2 hours can cause irritation to the eyes, nose, and throat.

Ammonia concentration and duration of exposure increase a person’s risk of adverse health outcomes. Exposure to 2,500–4,500 ppm of ammonia for 30 minutes or more can be fatal.

Side effects

The effects of long- or short-term use of smelling salts are unknown. However, a person should avoid overusing smelling salts or holding the smelling salt too close to the nose. Concentrated exposure can damage the upper airways and lungs and cause allergic reactions.

To use smelling salts, a person should keep them 10–15 centimeters (cm) from the nose when inhaling.

For people without underlying health issues, there is no evidence to indicate that using smelling salts as directed is dangerous. However, people with asthma and respiratory problems should be aware that they can result in difficulty breathing or increased airway irritation.


Surajit Jana.

Leave a Reply

Your email address will not be published. Required fields are marked *