Facial hair growth is regulated by androgens, primarily testosterone and its more potent derivative dihydrotestosterone (DHT). Hair follicles on the upper lip, chin, and jawline are highly sensitive to these hormones. When androgen levels rise, or when follicles become more responsive to normal levels, fine vellus hairs convert into thicker, pigmented terminal hairs. The National Institute of Diabetes and Digestive and Kidney Diseases identifies hirsutism, or excess coarse facial and body hair, as one of the most common signs of androgen excess.
Genetics also play a major role. Ethnic background influences both follicle density and androgen sensitivity, which is why patients of Mediterranean, South Asian, Middle Eastern, and Latin American heritage often notice more facial hair regardless of hormone levels. Targeting the follicle directly with laser hair removal for facial hair interrupts this growth at the source.
Hormonal shifts during puberty, pregnancy, perimenopause, and menopause can trigger or worsen the pattern. Conditions such as polycystic ovary syndrome (PCOS), thyroid imbalance, and adrenal disorders raise circulating androgens and frequently present with new or accelerating facial hair as one of the first visible signs.
