Smelling sticks, a protocol using manufactured scents like orange, lemon, and chocolate, have been shown in a randomized crossover placebo-controlled trial to help regain the sense of smell.

“smelling sticks there's actually a protocol that is used that these Mar markers that are manufactured in Europe where they have a different different orange lemon chocolate exactly and and smelling these things uh actually over there's a randomized crossover Placebo control trial that actually showed that they were able to regain their sense of smell by training their sense of smell with these sticks”