In response, some researchers are revisiting the concept of physical therapy for the nose in order to help restore what Covid-19 and other ailments have taken away. The only problem: nasal physiology is incredibly difficult to study, and the experimental therapy — while helpful to some — doesn’t provide the kind of evidence doctors normally need to adopt a new treatment widely.

— Read more in Post-Covid, Many Patients Try Smell Therapy. But Does it Work? at Undark.