[4] Side effects may include hair discoloration, skin irritation, and risk of systemic absorption and toxicity, among others.

[3] Selenium disulfide is sold as an antifungal agent in shampoos (such as Selsun Blue) for the treatment of dandruff and seborrheic dermatitis associated in the scalp with fungi of genus Malassezia.

[2][14] A 2015 systematic review of topical treatments for seborrheic dermatitis of the scalp identified only a single randomized controlled trial evaluating selenium disulfide for the condition.

[17] However, the review did suggest use of over-the-counter selenium disulfide shampoos as an inexpensive option for managing mild symptoms of seborrheic dermatitis.

Several scattered case reports of orange to red–brown scalp discoloration with selenium sulfide shampoo exist.

[7][21] The discoloration resolved shortly following discontinuation of selenium disulfide shampoo and its removal could be facilitated by lightly swabbing with isopropyl alcohol.

Case reports of temporary diffuse hair loss with selenium disulfide shampoo exist as well.

[1] Systemic symptoms may include tremors, weakness, lethargy, lower abdominal pain, and occasional vomiting.

[1] Selenium disulfide acts as an antifungal and keratolytic agent to treat seborrheic dermatitis and dandruff.

[25][26][27][28][29] However, application of selenium disulfide to damaged skin can result in systemic absorption and has been associated with cases of toxicity.

[34] Selenium disulfide has been suggested to be effective as a treatment for hyperkeratosis based on a small case series of three treated patients.