SARS-CoV-2 infection can leave long-term impacts on patients’ quality of life such as smell disorders. This multicenter, randomized, double-blind, placebo-controlled study examined the effect of palmitoylethanolamide and luteolin (PEA-LUT) supplementation combined with olfactory training in 185 subjects with a prior history of COVID-19 and persistent olfactory impairment. Treatment consisted in oral supplementation with placebo or 700 mg/day of ultramicronized PEA-LUT for 90 days, both combined with olfactory training.

Results showed significantly greater improvement in olfactory threshold, discrimination and identification scores in the intervention group compared to the placebo group (p = 0.0001). In addition, 92% of participants in the intervention group improved compared to 42% in the placebo group. The magnitude of recovery was significantly higher in the intervention group than in the placebo group (12.8 ± 8.2 vs. mean 3.2 + 3), with a 10-fold higher prevalence of anosmia in the placebo group compared to the intervention group.

Thus, palmitoylethanolamide and luteolin supplementation combined with olfactory training has beneficial effects in the recovery of smell after COVID-19-olfactory dysfunction.

Di Stadio A, D’Ascanio L, Vaira LA, Cantone E, De Luca P, Cingolani C, Motta G, De Riu G, Vitelli F, Spriano G, De Vicentiis M, Camaioni A, La Mantia I, Ferreli F, Brenner MJ. Ultramicronized palmitoylethanolamide and luteolin supplement combined with olfactory training to treat post-COVID-19 olfactory impairment: a multi-center double-blinded randomized placebo-controlled clinical trial. Curr Neuropharmacol. 2022 Apr 20.