What is the mode of action of Intrauterine system (levonorgestrel)?

• Primary: Prevents endometrial proliferation
• Also: Thickens cervical mucus

How quickly does the Intrauterine system taken to be effective contraceptive?

after 7 days

How long does a Intrauterine system last?

5 years (Mirena)

What are the common side effects of Intrauterine system?

• initial frequent uterine bleeding and spotting - which resolves
• infection/expultion/perforation