What hormones are in the Mirena IUD?
Mirena is a type of hormonal IUD that is over 99% effective at preventing pregnancy. This device contains a hormone medication called Levonorgestrel that is used in lots of other types of birth control methods as well (such as the pill). Levonorgestrel mimics a hormone that naturally occurs in your body called progesterone. The effect of this hormone is to stop ovulation from occurring (when the ovaries release an egg) and to thicken the cervical mucus (making it harder for sperm to pass through).
I have the Mirena IUD. Can my boyfriend ejaculate inside me or do we still need to use a condom?
As long as both of you have been tested for STI can can confirm neither of you have any (and you're in a monogamous relationship) then yes, your partner can ejaculate in your vagina and you'll still be over 99% protected from pregnancy. If there's any risk of STI transmission, however, then we strongly encourage using a condom.