Evaluate the Effect of Omega-3 vs Soy Isoflavones in Postmenopausal Women With Moderate to Severe Vasomotor Symptoms

Inclusion Criteria: * Ambulatory and can complete all study procedures, which are able to read, understand and sign an informed consent and willing to come to the center for study visits. * Postmenopausal (≥ 1 year of amenorrhea) or 6 months or more of amenorrhea with follicle stimulating hormone (FSH) ≥ 40 IU / L. * BMI ≥ 18 kg/m2 and ≤ 30 kg/m2 * Flushing of moderate to severe intensity. Exclusion Criteria: * Women with surgical menopause. * Treatment with hormone replacement therapy (HRT) in the 3 months prior to inclusion * Uterine bleeding after menopause with undetermined cause in the 12 months prior to screening. * Presence or history of malignancy in the past 5 years. * Malabsorption syndrome. * Hype or uncontrolled hypothyroidism. * Dyslipidemia (LDL-cholesterol\> 189 mg / dl or medical criteria) requiring an specific treatment of proven effectiveness. * Chronic renal disease. * Uncontrolled or untreated hypertension. * Treatment with isoflavones, tibolone, Selective Estrogen Receptors Moderators (SERM´s) in the past 3 months prior to the testing selection period. * Hormonal treatment with androgens, estrogens, progestins, alone or combined oral, transdermal, vaginal (including promestriene) or implant, in the last 3 months prior to testing selection period. * Patients who receive or require treatment with antidepressants or anticonvulsants * Patients with mental illness. * History of noncompliance with taking medication. * Suspected or abuse of alcohol or other drugs during the 12 months preceding the selection. * Use of any experimental drug or device within 30 days prior to the selection. * Any other condition or finding that a judgment of the investigator may jeopardise the tral conduct according to the protocol.