generic cialis online pharmacy The high expression of aromatase enzyme in the adipose tissue enhances the conversion of androgens into estrogens E which in turn exerts a negative feedback on hypothalamus and pituitary, inhibiting the production of gonadotropin releasing hormone GnRH, luteinizing hormone LH and follicle stimulating hormone FSH and, as a consequence, of T by the testis resulting in hypogonadotropic hypogonadism HH