At different stages of folliculogenesis, follicles are affected by different hormones. The growth of the dominant follicle at the initial stage is determined by gonadotropins (FSH and LH), and later by a combination of these hormones with the hormones of the hypothalamus, pituitary gland and ovaries, gonadotropin-releasing hormones (Gn-RH) and sex hormones (estradiol, progesterone, testosterone).