Trichotillomania is several times more common in women and has peak onset around puberty. The role of sex hormones, however, has received little research. 11 adolescent girls with trichotillomania, post-menarche and not taking birth control, were examined on a variety of clinical measures. Participants provided saliva samples for analysis of estradiol, progesterone, and testosterone levels. Lower progesterone was associated with more severe symptoms and lower levels of all hormones were associated with worse overall functioning. Adolescents with trichotillomania exhibit a range of hormone levels but that lower levels of certain hormones may have important clinical associations.