Hormonal and Non-Hormonal Contraception

Preventing pregnancy at different stages

Contraception means preventing pregnancy. It allows people to choose whether and when to have children. Methods work at different stages of reproduction: they may prevent an egg being released, stop sperm reaching an egg, or make fertilisation or implantation less likely.

Hormonal methods use hormones to alter reproductive processes. Non-hormonal methods work without administering hormones, for example by creating a physical barrier between sperm and an egg. Both groups contain several methods, with different benefits and limitations.

How hormones prevent pregnancy

Normally, FSH from the pituitary gland stimulates an ovarian follicle, containing an egg, to mature. LH then triggers ovulation, the release of an egg from the ovary. Hormonal contraception can interfere with these signals.

The combined contraceptive pill contains synthetic versions of oestrogen and progesterone. Oestrogen inhibits FSH release, reducing the stimulation of follicles so that an egg does not mature. Suppression of the hormonal signals needed for ovulation prevents an egg being released and available for fertilisation.

Progesterone also helps prevent pregnancy by making the mucus at the cervix, the entrance to the uterus, thicker. Sperm find it difficult to pass through this mucus, making fertilisation less likely. Progesterone can inhibit FSH and LH and therefore prevent ovulation, although some progesterone-only pills do not consistently stop ovulation. Some hormonal methods also thin the uterus lining, making implantation less likely.

The synthetic progesterone-like hormones used in contraception are called progestogens. This explains the name progestogen-only pill; at GCSE, their effects are often described as the effects of progesterone.

Different ways to deliver contraceptive hormones

The combined pill is taken daily. A progestogen-only pill contains no oestrogen and is also taken daily, according to its timing instructions. Avoiding oestrogen can make it suitable for some people who cannot use the combined pill for medical reasons.

Other methods deliver hormones without a daily pill:

• A patch releases oestrogen and progestogen through the skin and is usually replaced weekly during its prescribed cycle.
• An implant, fitted under the skin of the upper arm, releases progestogen continuously over several years.
• An injection supplies progestogen for several months, but repeat injections are needed.
• An intrauterine system (IUS) is fitted inside the uterus and releases progestogen over several years.

Long-acting methods reduce the chance of forgetting a daily dose. However, fitting or removing an implant or IUS requires a healthcare professional. An injection still depends on attending for the next dose on time.

Hormonal methods can cause side effects such as headaches, nausea, mood changes or irregular bleeding. Methods containing oestrogen carry a small increased risk of blood clots and are not suitable for everyone. None of these methods protects against sexually transmitted infections (STIs).

Non-hormonal methods: barriers and copper

A condom is a barrier worn over the penis that collects semen, preventing sperm entering the vagina. Condoms also reduce the transmission of STIs. They contain no contraceptive hormones, but must be used correctly each time and can split or slip off.

A diaphragm or cap fits over the cervix, blocking sperm from entering the uterus. It is used with spermicide, a chemical that kills or immobilises sperm. Correct placement matters, and spermicide used on its own is less reliable than many other methods. Unlike condoms, diaphragms should not be relied on for STI protection.

A copper intrauterine device (IUD) is fitted inside the uterus. It releases copper ions that impair sperm survival and function, making fertilisation less likely; it can also prevent implantation. It provides long-lasting contraception without hormones and does not require action each day. However, fitting requires a healthcare professional, and it does not protect against STIs.

The distinction between the two types of coil is important: an IUS releases hormones, whereas a copper IUD does not.

Permanent and behaviour-based methods

Sterilisation prevents sperm and eggs meeting. In males, the sperm ducts are cut or blocked so that sperm do not enter the semen. In females, the oviducts are cut or blocked so that sperm cannot reach an egg. It is highly effective and avoids the need for repeated contraceptive use, but it is intended to be permanent. Reversal is difficult and may fail, so it is unsuitable for someone who may want children later.

Natural family planning involves identifying fertile days around ovulation and avoiding intercourse during that time. It avoids contraceptive hormones and procedures, but requires careful monitoring. Ovulation can be difficult to predict, particularly when cycles vary, so everyday effectiveness is relatively low.

Abstinence from sexual intercourse prevents pregnancy resulting from intercourse, but depends on maintaining that choice. Natural family planning and sterilisation do not protect against STIs.

Effectiveness: correct use is not the same as everyday use

Contraceptive effectiveness is usually compared over one year. Perfect use means following the instructions correctly every time. Typical use includes everyday mistakes, such as missing a pill or using a condom incorrectly.

For example, 91% effectiveness with typical pill use means that about 9 out of 100 users experience an unintended pregnancy during a year. Over 99% effectiveness means fewer than 1 out of 100 users experience an unintended pregnancy in that period.

The small difference between perfect and typical use for implants and coils reflects how little they depend on repeated user action once fitted. In contrast, pills must be remembered and condoms must be used correctly each time. The injection is not as reliable in typical use as an implant because repeat doses can be late.

Reaching a justified judgement

There is no single best method for everyone. A useful evaluation weighs effectiveness, side effects, reversibility, STI protection and ease of use against the person's needs.

Someone who wants highly reliable, reversible contraception but often forgets tablets might prefer an implant or coil over a pill. A copper IUD offers high effectiveness without hormones, whereas an implant may suit someone comfortable using hormones. Both require professional fitting and neither protects against STIs.

Someone needing STI protection has a strong reason to use condoms. Using condoms alongside a highly effective contraceptive method can address both infection risk and pregnancy prevention. Sterilisation may suit someone certain they do not want future pregnancies, but its permanence is a major disadvantage for someone unsure about having children later.

A justified conclusion therefore links the method's mechanism and practical strengths to the person's priorities, while acknowledging its limitations.