Provexum However, for the effect to be, it is necessary to take Positron correctly. "Positron" is a drug containing levonorgestrel in a large dose (0.75 mg). During the reception, he carries out a massive hormonal attack on the body. Levonorgestrel is a synthetic analogue of progesterone, which directly affects conception and the course of pregnancy. "Positron" is able to change the contraction of the fallopian tubes and change the state of the endometrial so that the fertilized egg does not have the ability to attach to it. "Positron" is a fairly reliable contraceptive for emergency cases. Therefore, taking it according to the instructions or recommendations of the doctor, getting pregnant is extremely unlikely. However, we must remember that this drug is quite toxic, and you cannot use it regularly with each sexual intercourse. As a constant hormonal contraception it is better to take other drugs, after consulting with your gynecologist. Moreover, with frequent sexual intercourse, the effectiveness of “Positron” is significantly reduced. As an emergency way to protect you should drink only two tablets "Positron". The first is drunk within two days (48 hours) after sexual contact. The second must be taken 12 hours after the first dose. Sometimes gynecologists advise taking two tablets at the same time, but it is better if you strictly follow the instructions for the preparation. The advice to drink two pills at once is due to the fact that many women, after drinking the first pill of “Positron”, forget about taking the second one or lose it. In some cases, the reception of "Positron" will not only be ineffective, but also cause complications. You cannot take the drug if - there is a suspicion of pregnancy; - more than two days passed after coitus; - if the last menstrual cycles were unusual or irregular; - if there is a risk of allergy to the drug. It is undesirable to use "Positron" in diseases of the liver, blood, blood vessels and heart, breast oncology (in history). Among the side effects can be distinguished bloody discharge from the vagina, dizziness and headache, abdominal cramps and fatigue.