The oral contraceptive, which is known as the pill, contains oestrogen or progesterone. These hormones prevent the production of FSH, so eggs cannot mature.
Benefits and risks of hormonal contraception
Oral contraceptives are more than 99% effective if taken correctly and can reduce the risk of certain cancers.
However, there are possible side effects, such as changes in weight, mood and blood pressure due to high levels of oestrogen. Modern pills contain much less oestrogen.
Contraceptive injections, implants or skin patches contain slow release progesterone to prevent the maturation and release of eggs.
Fertility can be controlled without hormones.
These methods include:
physical barrier methods such as condoms and diaphragms, which prevent the sperm reaching an egg
intrauterine devices (IUD) also known as a coil, prevent the implantation of an embryo or release of a hormone
spermicidal agents which kill or disable sperm
abstaining from intercourse when an egg may be in the oviduct
surgical methods of male and female sterilisation, eg a vasectomy, where the sperm ducts are cut and tied
Benefits and risks of non-hormonal contraception
Condoms are easy and quick to use, but sometimes they can tear or rip.
Diaphragms need to be put in just before sex and left in several hours afterwards.
IUDs need to be fitted by a health professional. IUDs can remain in position for up to 10 years. However, there is a small risk of causing an ectopic pregnancy, which leads to complications for both the mother and the foetus.
Spermicidal agents can be added to other physical barriers such as condoms, but some people can have allergic reactions to these.
Abstaining can be used successfully, but if the timings are not accurate, the chance of pregnancy is high.
Surgical methods cannot be reversed, and is considered permanent.