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Olfactory Training to Boost Recovery from Post-COVID-19 Smell Disorder


Clinical Trial determines that olfactory training helps recovery from post-Covid-19 smell disorder

The COVID-19 pandemic has affected millions worldwide, causing many symptoms that can persist long after recovery. One of the most common and persistent symptoms is olfactory dysfunction, including the partial loss of smell known as hyposmia. This condition can significantly impact the quality of life, making it difficult to enjoy food and detect potential dangers, such as gas leaks and smoke.

Olfactory training can effectively treat post-viral olfactory dysfunction. However, there is still much to learn about promoting recovery from smell disorders after post-COVID-19. It has been suggested that neuroinflammatory events within the olfactory bulb and the central nervous system may be responsible for smell disorders after SARS-CoV-2 infection. Therefore, targeting neuroinflammation is one potential strategy for promoting recovery from post-COVID-19 chronic olfactory dysfunction.

Clinical Trial

Palmitoylethanolamide and luteolin (PEA-LUT) are candidate anti-inflammatory/neuroprotective agents that may effectively improve post-COVID-19 smell disorders. In a recent multicenter double-blinded randomized placebo-controlled clinical trial, researchers investigated the recovery of olfactory function in patients treated with PEA-LUT oral supplements plus olfactory training versus olfactory training plus placebo.

The study included 185 patients with prior COVID-19 and persistent smell impairment >6 months after follow-up SARS-CoV-2 negative testing without previous history of olfactory dysfunction or other sinonasal disorders. Participants were randomized to daily oral supplementation with ultra-micronized PEA-LUT 770 mg plus smell training (intervention group) or smell training with placebo (control). Sniffin' Sticks assessments were used to test the patients at baseline and 90 days.

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The intervention group showed significantly greater improvement in the olfactory threshold, discrimination, and identification scores than the controls. Overall, 92% of patients in the intervention group improved versus 42% of controls. The magnitude of recovery was significantly greater in the intervention group versus control (12.8 + 8.2 versus mean 3.2 + 3), with >10-fold higher prevalence of anosmia in control versus intervention groups at the 90-day endpoint.


Among individuals with olfactory dysfunction post-COVID-19, combining PEA-LUT with olfactory training resulted in greater recovery of smell than olfactory training alone. This suggests that PEA-LUT may be a promising treatment for olfactory dysfunction caused by neuroinflammation and could help to improve the quality of life of those affected by this condition. Further research is needed to confirm these findings and understand the mechanisms underlying olfactory dysfunction after COVID-19.

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This content is for informational and educational purposes only. It is not intended to provide medical advice or to take the place of such advice or treatment from a personal physician. All readers/viewers of this content are advised to consult their doctors or qualified health professionals regarding specific health questions. CenTrial Data Ltd. does not take responsibility for possible health consequences of any person or persons reading or following the information in this educational content. Treatments and clinical trials mentioned may not be appropriate or available for all trial participants. Outcomes from treatments and clinical trials may vary from person to person. Consult with your doctor as to whether a clinical trial is a suitable option for your condition. Assistance from generative AI tools may have been used in writing this article.