Abstract
Hair concentrations of cortisol, cortisone, and testosterone are non-invasive measures of cumulative steroid hormone levels. Use of contraceptives co-varies with levels of cortisol and cortisone in women's hair. It is unclear, however, how different contraceptive methods (i.e., that differ in their steroid hormone composition) affect corticosteroid and testosterone hair levels. The current study examines associations of contraceptives with hair steroid hormone concentrations in females from the community (N = 464, M = 20.6 years old, age range = 19-22). Self-reported contraceptives were first categorized as combined estrogen-progestin or progestin-only, and then analyzed individually in follow-up analyses. Multiple regressions adjusting for body mass index (BMI) and hair characteristics revealed that levels of hair cortisol, cortisone, and testosterone were significantly lower in women who used combined estrogen-progestin methods than in women who did not use hormonal contraception (β(cortisol(log)) = -0.29; β(cortisone(log)) = -0.28; β(testosterone(log)) = -0.36), showing moderate to large effect sizes (d = 0.64, d = 0.71, and d = 0.81, respectively). Concentrations of hair cortisol were lower in women who used progestin-only contraceptives (β = -0.49) compared to no contraceptive use, with a large effect size (d = 1.67). Follow-up analyses revealed that the association of the three steroid hormones with estrogen-progestin methods was strongest for the combined oral "micro-pill." Future studies of hair steroid hormones should take into account the specific type of contraceptive used, as this may affect study results.