Sebum

Sebum is a lipid-rich fluid secreted by sebaceous glands that helps lubricate and protect the scalp and hair. Made mainly of triglycerides, wax esters, squalene and free fatty acids, sebum creates a barrier that keeps the skin moisturized, prevents excessive water loss, and supports the scalp’s microbiome; its production varies with age, hormones, genetics and environmental factors.

When sebum production is excessive the scalp can become oily, hair may appear limp, and the environment may promote dandruff, seborrheic dermatitis or folliculitis; conversely, too little sebum can lead to dryness and brittleness. Management focuses on gentle scalp care and targeted medicated shampoos or topical treatments to rebalance oiliness, and persistent or severe symptoms should be evaluated by a dermatologist to address underlying causes and appropriate treatment options.