This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Contraceptives, Subject name: Gynaecology & Obstetrics
Mirena (LNG IUCD) has to be replaced after : 
Select and explain. 
A. 1 year, B. 5 years, C. 3 years, D. 6 months
B: 5 years
Answer: B: 5 years 
Explanation: Mirena (LNG IUD) contains a total of 52 mg levonorgestrel (LNG) LNG is released into the uterine cavity at a rate of approximately 20 microgram/day. Act mainly by local progestogenic effects Effective for up to 5 years.