AHFS/Drugs.com Monograph ATC code D01AE13 (WHO) | Routes ofadministration Topical Legal status US: OTC | |
Pregnancycategory US: C (Risk not ruled out) | ||
Selenium disulfide is a medication used to treat pityriasis versicolor and seborrhoeic dermatitis (dandruff). It is applied to the affected area as a lotion or shampoo. Dandruff frequently returns if treatment is stopped.
Contents
Side effects include hair loss, irritation of the skin, weakness, and feeling tired. Use in not recommended in children less than 2–5 years old. Use in pregnancy or breastfeeding has not been studied. Selenium disulfide is an inorganic compound with the chemical formula SeS2.
Selenium disulfide was approved for medical use in the United States at least as early as 1951. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. Selenium disulfide is avaliable as a generic medication and over the counter. In the United States a month of treatment costs less than 25 USD. In the United Kingdom 100 ml of 2.5% shampoo costs the NHS about 1.96 pounds.
Medical uses
Selenium disulfide is sold as an antifungal agent in shampoos for the treatment of dandruff and seborrheic dermatitis associated in the scalp with Malassezia genus fungi. In the United States, a 1% strength is available over-the-counter, and a 2.5% strength is also available with a prescription. At the 2.5% strength, selenium disulfide is also used on the body to treat tinea versicolor, a type of fungal skin infection caused by a different species of Malassezia.
Side effects
Selenium disulfide can cause discoloration of the hair and alter the color of hair dyes. It may also discolor metallic jewellery. Selenium monosulfide (SeS) is the only selenium compound so far identified as a carcinogen in animals.
Chemical composition
Selenium disulfide has a composition that approximates to SeS2 and is sometimes called selenium sulfide. However, as used in proprietary formulations, it is not a pure chemical compound but a mixture where the overall Se:S ratio is 1:2. The compounds are Se–S rings containing a variable number of S and Se atoms, SenS8−n.
Many selenium sulfides are known as indicated by 77Se-NMR spectroscopy.
History
Selenium monosulfide, along with elemental selenium and sulfur, has been used in medicinal preparations in the past, causing confusion and contradiction as to exactly what form selenium is in any given topical preparation.