What should you know about shampoos for dandruff and oily hair?

Oil on the scalp can make flakes cling to the roots and may leave hair looking greasy soon after washing. Dandruff often produces loose flakes, while seborrheic dermatitis may add itch, redness and greasy scale. The appearance alone cannot identify the cause.

Frequent washing is not automatically harmful when the scalp is oily, but strong scrubbing, very hot water and fragranced products can aggravate sensitive skin. The goal is a clean scalp with a comfortable skin barrier, not a stripped or tight feeling.

Wet the scalp fully, apply shampoo to the roots, and massage with fingertips rather than nails. Rinse well. If using a medicated shampoo, follow its label or clinician’s instructions about contact time and frequency; do not compensate for missed applications by using extra product. Keep conditioner mainly on the lengths, and wash after heavy styling-product use.

See a dermatologist if flaking and oiliness continue after a consistent routine, or if symptoms affect the hairline, ears or face. Prompt assessment is needed for painful swelling, crusting, pus, bleeding, severe itch, or patchy hair loss. A clinician may recommend medicated shampoo treatment or topical antifungal treatment when appropriate.

Ask whether the scale suggests dandruff or seborrheic dermatitis, how often to wash, which active ingredient suits your scalp, and when to change or stop treatment.