Evidence check: Cortisol in the context of fertility

Cortisol, the primary stress hormone, is regulated by the HPA axis. Chronically elevated cortisol can impair fertility by suppressing gonadotropin release (LH, FSH) and disrupting menstrual cycles. Observational studies link high cortisol with longer time-to-pregnancy, but evidence is associative, not causal. A single cortisol blood test is insufficient for fertility assessment; it should be interpreted alongside cycle phase, other hormones (e.g., progesterone, estradiol), and validated stress questionnaires. MyBody-X offers hormone panels, but their predictive value for fertility is limited. For individuals trying to conceive, a comprehensive workup by a gynecologist or endocrinologist is recommended. Salivary cortisol day profiles may indicate HPA axis dysregulation but are not standalone diagnostic tools. Evidence is moderate: human observational data support the link, but interventional trials are lacking.