Smell training is the best way to recover lost sense after COVID, researchers say

NORWICH, United Kingdom — Losing the sense of smell is a common symptom among COVID-19 patients. While most will recover fairly quickly, a significant portion of people report long-term issues. Some have turned to steroids (inflammation lowering corticosteroids) for relief, but a new study finds the best way to help recover is by simply “training” yourself to smell again.

Researchers from the University of East Anglia explain this involves sniffing at least four different odors twice per day for several months.

“The huge rise in smell loss caused by COVID-19 has created an unprecedented worldwide demand for treatment. Around one in five people who experience smell loss as a result of Covid-19 report that their sense of smell has not returned to normal eight weeks after falling ill,” says smell loss expert Professor Carl Philpott from UEA’s Norwich Medical School in a university release. “Corticosteroids are a class of drug that lowers inflammation in the body. Doctors often prescribe them to help treat conditions such as asthma, and they have been considered as a therapeutic option for smell loss caused by Covid-19. But they have well-known potential side effects including fluid retention, high blood pressure, and problems with mood swings and behavior.”

How long does it take for COVID patients to smell again?

Study authors carried out a systematic, evidence-based review to see if corticosteroids could help people regain their sense of smell.

“What we found that there is very little evidence that corticosteroids will help with smell loss. And because they have well known potential adverse side effects, our advice is that they should not be prescribed as a treatment for post-viral smell loss,” Prof. Philpott explains. “There might be a case for using oral corticosteroids to eliminate the possibility of another cause for smell loss actually being a confounding factor, for example chronic sinusitis – this is obviously more of a diagnostic role than as a treatment for viral smell loss.”

The majority of people (90%) who lose their sense of smell due to COVID-19 will eventually regain full nasal abilities after six months. Still, smell training can help speed up the recovery process.

“It has emerged as a cheap, simple and side-effect free treatment option for various causes of smell loss, including COVID-19,” Philpott concludes. “It aims to help recovery based on neuroplasticity – the brain’s ability to reorganize itself to compensate for a change or injury.”

The study appears in the journal International Forum of Allergy & Rhinology.