The subject of the present invention for the treatment of endometriosis is the provision of a parenteral pharmaceutical form (release system) for the controlled release of an aromatase inhibitor (AI) with a daily release rate which does not induce any stimulation of the ovaries by negative feedback of the hypophyseal-ovarian axis (which would induce the secretion of gonadotropins and the stimulation of the ovarian follicular growth), and of a gestagen with a daily release rate of below the ovulation-inhibitory dose, which provides a contraceptive effect based on local effects (for example the reduction and thickening of the cervical mucus to prevent the ascent of sperm, effects on the endometrium and on tubal motility in order to hinder the implantation and the transport of ovules).
