Selsun Suspension is an antifungal preparation used to treat and control dandruff and tinea versicolor (a common fungal infection causing small, discoloured patches of skin). It contains selenium as an active ingredient which acts by slowing down the cell growth of the scalp layer that cause dandruff.

Selenium sulfide exerts a cytostatic (inhibits the cell growth) effect on follicular epithelium and epidermis cells, which decreases the production of corneocytes (cells which produce outer layer of the skin). As a result, it relieves itching and flaking of the scalp and removes the dry, scaly particles.