The Abrasive Aroma Behind Smelling Salts

  • Published2 Jul 2020
  • Source BrainFacts/SfN

Smelling salts can revive someone who fainted, and some athletes have been spotted taking a whiff during games. How does this centuries-old treatment work?

Storyboard and animation produced by Midnight Snacks for

Scripting by Michael W. Richardson and Juliet M. Beverly.

Editorial Production by Hannah Zuckerman and Juliet M. Beverly.



A ghastly sight crosses the gaze of an anxious fan and suddenly it’s lights out. They fainted.

Quick! Someone get the smelling salts!

A doctor quickly places a vial under their nose and they wake back up.

It looks like the boxer could use some attention, too.

The contender is knocked out cold in the boxing ring.

A cornerman rushes to stick an open packet of smelling salts under the fighter’s nose.

For centuries smelling salts have been used to wake an unconscious person.

But why?

Fainting is typically caused by a lack of oxygen to the brain. Without enough oxygen delivered, the brain starts to shut down.

When a packet of smelling salts is placed under the nose, the fumes start to burn the membranes in the nasal passage of the unconscious person.

This crystallized concoction is made with ammonia — the fumes of which are caustic. Think of getting a whiff of old-school oven or grill cleaners.

Even without conscious input from your brain, your lungs react to this irritant to rid your airways of the painful fumes by breathing in and out deeply.

These big bursts of air bring more oxygen into your body, which is carried to the brain through your bloodstream.

Once your brain gets that much needed oxygen, it comes back online.

That’s good news for our fan in the ring-side seats, but what about the boxer?

Here’s the thing: getting knocked out is an impact-related brain injury, not a blood-oxygen issue, like fainting.

A whiff of smelling salts isn’t going to help get the boxer up for the count.

Football, basketball, and hockey players have all been seen using smelling salts while conscious, claiming it helps keep them alert for long games or after a big hit.

Use of smelling salts in this manner may give athletes a jolt because that strong irritant causes them to take deeper breaths, taking in more oxygen, and thus making them feel more awake.

But the science doesn’t really back this.

So, unless you’ve had a spell like our ‘fainting fan,’ smelling salts won’t do much.

Sorry, champ. There’s no quick cure for this.

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