Which statement about using ketoconazole 2% shampoo is correct?

• A. It should be applied once daily for up to 5 days, leaving on for 3-5 minutes
• B. It should be taken orally
• C. It should be applied to the scalp and left on for 3-5 minutes
• D. It has no systemic absorption

Answer: (C)

Ketoconazole 2% shampoo works mainly as a topical antifungal, so the key is applying it directly to the scalp and giving it enough time to act. When you massage it onto a wet scalp and leave it in place for about 3–5 minutes, the active ingredient stays in contact with the scalp's surface long enough to penetrate the outer skin layers where Malassezia yeast and other fungi reside. This contact time maximizes the antifungal effect before you rinse it out, improving efficacy for conditions like dandruff, seborrheic dermatitis, or fungal scalp infections.

It isn’t taken by mouth; this product is used topically. There is some systemic absorption from topical use, but it is minimal, so saying there is no systemic absorption isn’t accurate. Remember to rinse thoroughly after the contact time to avoid irritation and residue.