Retinoids are drugs with structural similarity to naturally-occurring vitamin A. They interact with retinoid receptors in cell nuclei with a wide range of effects including reducing the production of sebum by sebaceous glands. A number of retinoids are available topically including tretinoin, isotretinoin and adapalene. Retinol, whilst not technically a retinoid, has similar actions and is available without prescription in over the counter products.

Topical retinoids can be effective treatments for mild acne being particularly effective for comedomal acne which is dominated by whiteheads and blackheads. They are less likely to be effective treatments for moderate acne although can be used in combination with other treatments such as oral antibiotics.Topical retinoids (and retinol) can also improve hyperpigmentation (dark marks) and fine lines.

Topical retinoids are generally safe. It is important that they are not used by women who are pregnant or who are at risk of becoming pregnant since they are absorbed to a small extent through the skin and carry a risk of fetal malformation. They can cause skin dryness, peeling and irritation. This can be minimized by using a lower concentration preparations on alternate days.