oestrogen can be used to prevent the release of an egg so can be used as contraception
if oestrogen is taken every day to keep the level of it permanently high, it inhibits the production of FSH and after a while egg development and production stops and stay stopped
Progesterone reduces fertility by stimulating the production of thick mucus which prevents sperm getting through and reaching an egg
combined oral contraceptive pill
contains oestrogen and progesterone
over 99% but can cause side effects like headaches and nausea no protection against STDs
progesterone only pill
fewer side effects and just as effective
contraceptive patch
oestrogen and progesterone
patch stuck to skin lasting a week
contraceptive implant
inserted under skin of the arm
releases continuing amount of progesterone which stops ovaries releasing eggs
lasts 3 years
contraceptive injection
contains progesterone
dose lasts 2-3 months
IUD
t shaped device inserted to uterus kill sperm and prevent implantation of a fertilised egg
