Women Of childbearing age (this period), without desire for fertility, without treatment for endometriosis in the past three months, with ultrasound diagnosis of endometrioma (unilateral or bilateral) minor diameter to 4 centimeters. Those who do not go to surgical procedure and who choose or who are instructed to follow a medical management. No contraindications to oral contraceptive use, rating and eligibility criteria of WHO 1 (no restriction can be used in all circumstances) or 2 (the advantages of using the method generally outweigh the risks, usually can be used) . And who they entered the University Hospital Fundación Santa Fe de Bogota.