Acne occurs when oil glands become plugged. Normally, sebum (oil) flows out of the gland and out a pore to the skin's surface. Acne occurs when this path gets blocked and sebum cannot reach the skin's surface. The main contributors to blockages are skin cells and thickened sebum. A common bacterium called P. acnes grows excessively in clogged gland, contributing to pimple formation. The most acne-prone and are located on the face, back and chest.

The major influences of acne during puberty are hereditary and hormones. Foods and cleanliness play little if any role. Stress can make acne worse, while sunlight, though damaging to the skin overall, may temporarily improve acne. Adult onset acne can be caused by many things, including hereditary, stress and hormonal factors. Adult women are much more likely to develop adult onset acne. Pregnancy, hormonal irregularities in the menstrual cycle, and ovarian cysts may all contribute to a woman developing acne.

Salicylic acid is particularly helpful for basic acne (acne vulgaris) because it prevents bacteria from clogging the pores. It also inhibits blackheads and whiteheads. See Salicylic acid treatments >>

Benzoyl peroxide is a chemical found in spot treatments that effectively dries or peels congested areas such as cystic acne or inflamed pustules. See Benzoyl peroxide treatments >>

Glycolic acid is a common alpha hydroxy acid that penetrates the skin, purging clogged pores. Glycolic acid works well for mild to moderate acne. See Glycolic acid treatments >>

Retinol is a form of vitamin A often recommended for adult acne. Adult skin cannot typically tolerate more powerful ingredients like Benzoyl Peroxide and Glycolic acid. Retinol also has anti-aging properties, making it great for mature skin. See Retinol treatments >>