<unk> s (alternative spellings:<unk> s or<unk> s) are a group of steroid compounds, named for their importance in the<unk> rous cycle, and functioning as the primary female sex hormone.<unk> s are used as part of some oral contraceptives, in<unk>  replacement therapy of postmenopausal women, and in hormone replacement therapy for transwomen.
Like all steroid hormones,<unk> s readily diffuse across the cell membrane; inside the cell, they interact with<unk>  receptors.
Estrogen
Estradiol 
Androgen
Progesterone 
Inhibin
Methyltestosterone
Thyroid hormone
Steroid hormone