What Is Selenium Sulfide?
Selenium sulfide is an active ingredient in over-the-counter dandruff products. Under 21 CFR 358.710, the FDA lists it for controlling dandruff at 1 percent, or 0.6 percent in micronized form, which the rules define as selenium sulfide finely ground to a median particle size of about 5 micrometers. The FDA's over-the-counter monograph for dandruff, seborrheic dermatitis and psoriasis, a final order effective March 27, 2020, also lists selenium sulfide at 1 percent for seborrheic dermatitis.
FDA rules require these products to carry the warnings "For external use only," to avoid contact with the eyes and rinse thoroughly with water if contact occurs, and to consult a doctor if the condition worsens or does not improve after regular use.
ATSDR says the EPA has determined that selenium sulfide is a probable human carcinogen, and notes that selenium sulfide is not present in foods and is a very different chemical from the organic and inorganic selenium compounds found in foods and the environment.
Sources checked September 15, 2026. Every point below links the page it came from.
The sources behind this answer
- Regulatory filingUnder 21 CFR 358.710, active ingredients for controlling dandruff include selenium sulfide at 1 percent and micronized selenium sulfide at 0.6 percent. US FDA, 21 CFR part 358 (eCFR) ↗
- Regulatory filingThe FDA's OTC Monograph M032, a final order effective March 27, 2020, lists selenium sulfide at 1 percent as an active ingredient for controlling seborrheic dermatitis. US FDA, OTC Monograph M032 ↗
- Regulatory filingThe FDA requires dandruff products with these ingredients to warn for external use only, to avoid eye contact and rinse if it occurs, and to consult a doctor if the condition worsens or does not improve. US FDA, 21 CFR part 358 (eCFR) ↗
- Regulatory filingFDA rules define micronized selenium sulfide as selenium sulfide finely ground to a median particle size of approximately 5 micrometers. US FDA, 21 CFR part 358 (eCFR) ↗
- Government sourceATSDR says the EPA has determined selenium sulfide is a probable human carcinogen, and that it is not present in foods and differs greatly from selenium compounds found in foods. ATSDR, CDC ↗
Sources checked September 15, 2026. A brand statement is the company’s own claim, which we report but have not verified. Our grades are model-based estimates, not lab tests.