<s>[INST] Dear Sir/MadamI would like to say you that i want to use unwanted 72 but i don't know how to use it and what is side effect of this..?, so please tell me everything about this in details....secondly can i use unwanted 72 for long time or not..?Regards:S.Alam YYYY@YYYY [/INST] Hello and welcome, Unwanted 72 is an emergency contraceptive. It is designed to be used when there is unexpected sexual episode and no other contraceptive is available. It is not to be used on a regular basis. The dose is if it is a single tablet of 150 mg then one tablet is to be taken as soon as possible within 72 hours after unprotected sex. If there are 2 tablets of 75 mg each then one tablet is taken as soon as possible within 72 hours of unprotected sex and the second tablet is taken 12 hours after the first. In one menstrual cycle this can be used only once. It prevents pregnancies in 97% cases if used early. The common side effects are nausea and vomiting and irregular periods. It is not a replacement to regular contraception and we advise regular contraception like pills, condoms, IUD or implants if the frequency of sexual contact is regular and more than once every 6 months. Hope this satisfies your query. Thanks for using HCM.     Feel free to ask any more questions that you may have. Dr Madhuri BagdeConsultant Obstetrician and Gynecologist </s>