Yohtek, also known as levonorgestrel tablets, can be taken by a healthy woman of 40 years of age, but is prohibited for women over 40 years of age to avoid adverse effects such as thrombophilia. Levonorgestrel tablets are an emergency contraceptive. Usually taken within 72 hours can play a good contraceptive effect. Due to the large hormone content, it should not be used when you are over 40 years old to prevent causing problems with coagulation, leading to the formation of blood clots. It is worth noting that taking levonorgestrel tablets can cause dizziness, vomiting, breast swelling and pain and other adverse symptoms, while high blood pressure, diabetes, mental depression is prohibited, so be sure to use it reasonably under the guidance of a doctor. If you take Yutin appeared more serious adverse reactions, be sure to go to the hospital in time to check the consultation, under the guidance of the doctor for treatment.