Intensive Olfactory Training in Post-COVID-19 Patients: A Multicenter Randomized Clinical Trial.

Background: Olfactory dysfunction (OD)-including anosmia and hyposmia-is a common symptom of COVID-19. Previous studies have identified olfactory training (OT) as an important treatment for postinfectious OD; however, little is known about its benefits and optimizations after SARS-CoV-2 infection.

Objective: This study aimed to assess whether olfactory training performance can be optimized using more fragrances over a shorter period of time in patients with persistent OD after COVID-19.