Hi, Microgynon contains both ethinyl estradiol and levonorgesterol which is used in the treatment of heavy, painful or irregular menstrual periods. It is also used to prevent unwanted pregnancies from unprotected sexual activities. Microgynon may cause premenstrual syndrome (PMS) like symptoms such as hot flashes, flushed skin, night sweats, stomach cramps or pain, mood swings, depression, breast tenderness and enlargement, changes in appetite, irritability, fatigue, acnes, changes in sleep pattern, restlessness etc. Other side effects of Microgynon are irregular uterine bleeding, vaginal discharge, vaginal bleeding, nausea, vomiting, abdominal bloating, GIT upset, indigestion, delayed wound healing, vaginal dryness, dry mouth, unusual tiredness and weakness, headache, easily bruising or bleeding, allergic reactions etc. If these side effects persist for long or bother you, then you should inform your doctor first for medical help. No interactions were found between Microgynon as well as Vitamin B-100 complex. Usually, Vitamin B-100 has no effect on menstrual cycles. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Zubayer Alam, General And Family Physician