Farnesol is best approached with caution on seborrheic-dermatitis-prone skin because it is used for fragrance and deodorant effects and is subject to fragrance-allergen labelling rules. Fragranced leave-on products can be uncomfortable when the skin barrier is already inflamed.

A laboratory study found activity against biofilms from canine Malassezia isolates, but that does not make Farnesol a proven human seb derm treatment or cancel its irritation and allergy potential. During an active flare, a fragrance-free alternative is usually easier to assess; stop if redness, burning or itching increases.