Komedogen

Komedogen, or comedogenic in English, describes the property of certain substances to clog pores and promote the formation of comedones, the whiteheads and blackheads commonly seen in acne. In cosmetic science, the term is used to categorize ingredients and products by their potential to block hair follicles.

Comedogenicity relates to how mixtures of sebum, keratin, and debris collect within follicles. When pore openings become obstructed, comedones can form and may contribute to acne, especially in individuals with oily or acne-prone skin. The degree of pore clogging depends on the ingredient, its concentration, the overall formulation, and individual skin biology, so responses vary widely among people.

Assessment of comedogenicity is not standardized across all products. Ingredients are often given a comedogenic rating on scales that range from 0 (noncomedogenic) to 5 (highly comedogenic), based on patch tests, human studies, or historical data. However, results can differ by formulation and by how long the product remains on the skin. Because there is no universal standard, manufacturers may provide varying information, and consumer guides should be interpreted with caution.

Common guidance for those with acne-prone skin is to prefer formulations labeled noncomedogenic and to be cautious with ingredients repeatedly flagged as comedogenic in guides. Examples that are frequently discussed in consumer literature include certain esters such as isopropyl myristate and isopropyl palmitate, which some individuals find pore-clogging. Individual tolerances vary, so patch testing and mindful observation of how the skin responds remain important.