The non-hormonal IUD is effective immediately after it’s inserted. The hormonal IUD is effective immediately if you get it inserted within 7 days of the start of your period. Otherwise it takes a little longer to become effective, so you should use a back-up method, such as condoms or internal condoms, for 7 days after insertion.
How soon does an IUD become effective after you get it?
updated about 4 years ago