Yasmin contains Drospirenone (a synthetic hormone progestin)and Ethinyl Estradiol and is used as a preventive drug to avoid pregnancy. It interferes with woman menstrual cycle and tricks the body as if ovulation has taken place even if it has not. So a ripened egg is not released by the ovaries. The drug changes condition of cervical mucus and uterine lining and hampers movement of sperm cells to the uterus and attachment of a fertilized egg to the uterus.
Start treatment on the very first day of your menstrual cycle and then take one pill daily. If you missed a daily dose take taking two pills as a single dose. Risk of your pregnancy increases if you miss more than one dose. Do not take another contraceptive pill concomitantly with Yasmin to avoid serious hormonal imbalance. Each pill contains 3.0 mg of drospirenone and 0.030 mg of Ethinyl estradiol, while 7 'inactive' pills do not contain the hormones.
You should not use this medication in patients with hypersensitivity to the medication, undiagnosed abnormal genital bleeding, breast cancer (known, suspected, or in history), known or suspected estrogen-dependent neoplasia, blood clots, myocardial infarction, pregnancy, breastfeeding, problems with liver, plague. The medication cannot be used in the girls who have not yet had their first menstrual period. 
Yasmin may increase potassium levels in some individuals, thus, women with kidney disease, liver bug, or adrenal disease should not be treated by it. Also, some women may develop nausea, vomiting, weight gain, headaches, palpitations, fainting or dizziness, breast tenderness and enlargement, changes in the menstrual cycle, vaginal thrush, water retention in the body. More serious but rare adverse reactions include an increase in blood pressure, depression, liver disorders and blood clots in vessels. 
If you missed a pill risk of becoming pregnant increases. If you forgot to take one 'active' pill, take two pills as soon as you remember then return to your schedule. If you miss two 'active' pills in a row in the first or second week of treatment, take two pills a day for two days in a row. Then return to your schedule. Use birth control test during seven days if such a 'mistake' occurred. If you miss two 'active' pills in a row during the third week, or if you miss three pills in a row during any of the first three weeks, you need to start a new pack of pills as if you are a First Day starter. 
If you did not take three 'active' pills in a row during any of the first three weeks, start a new pack on the same day as if you are a First Day starter. 
If you skipped intake of two or more pills, you may not have monthlies during this month. If you miss a period for two months in a row you might be pregnant. 
If you miss any reminder pills, throw the missed pills away and return to your schedule.
Signs of overdose include nausea and vomiting, vaginal bleeding, increased level of blood potassium. If you suspect overdose contact your health care provider the soonest or seek immediate medical attention.
Store at room temperature, below 25 C (77 F) and out of reach and children and pets.