Cycle basics · 7 minute read
Your cycle hormones: FSH, LH, estrogen, and progesterone
A plain-language map of the four hormones most often discussed in cycle tracking.
Evidence-informed · Editorial review August 2026 · Links to trusted sources are available in the interactive app
FSH supports follicle development
Follicle-stimulating hormone is released by the pituitary gland. Early in a cycle, it helps ovarian follicles grow and supports selection of a dominant follicle.
Estrogen and LH help coordinate ovulation
A growing follicle makes estrogen. When estrogen remains high enough, feedback to the brain contributes to an LH surge. That surge is the signal closely associated with impending egg release.
Progesterone characterizes the luteal phase
After ovulation, the corpus luteum produces progesterone. It supports the uterine lining and is associated with the post-ovulation temperature shift. Hormones work as a connected system, so one symptom cannot identify an exact level.