Palmitoylethanolamide and Luteolin for Postinfectious Olfactory Disorders: How Clinically Meaningful Is Its Effect?

The prevalence of post-viral olfactory dysfunction has increased significantly during the COVID-19 pandemic, posing a major challenge for patients and practitioners. While olfactory training (OT) is a common approach to therapy, there has been increasing interest in supplementing therapy with a combination of palmitoylethanolamide (PEA) and luteolin (LUT), which are known for their anti-inflammatory properties. In this study, their efficacy in the treatment of patients with olfactory loss following upper respiratory tract infections, mainly COVID-19, was investigated in an outpatient clinic.

Fifty patients with persistent olfactory dysfunction were randomized to two groups: one receiving OT and PEA-LUT, the other OT alone. Olfactory function was evaluated before and after treatment.

The study group showed significant improvements in odor discrimination and overall olfactory function (TDI score) after treatment with PEA-LUT and OT, while the control group did not. However, when clinically meaningful improvements were considered, there was no significant difference between the groups.

The present study suggests that while PEA-LUT may have the potential to improve olfactory function in post-viral dysfunction, the additional benefit over OT alone may be limited. These results contrast with some previous studies.