• December 18, 2021
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Combined Pills

The combined oral contraceptive pill is usually just called “the pill”. It contains synthetic female hormones, estrogen, and progesterone. These hormones are produced naturally in a woman’s ovaries.

The hormones in the pill prevent a woman’s ovaries from releasing an egg (ovulating). They also make it difficult for sperm to reach an egg, or for an egg to implant itself in the lining of the womb.

The pill is usually taken to prevent pregnancy, but can also be used to treat painful periods, heavy periods, premenstrual syndrome (PMS), and endometriosis.

At a glance: the combined pill

  • When taken correctly, the pill is over 99% effective at preventing pregnancy. This means that fewer than one woman in 100 who use the combined pill as contraception will get pregnant in one year.
  • As humans make mistakes, in real world use at least 8 women in 100 a year become pregnant (92% effective).
  • You need to take the pill every day for 21 days, then stop for seven days, and during this week you have a period-type bleed. You start taking the pill again after seven days.
  • You need to take the pill at the same time every day. You could get pregnant if you don’t do this, or if you miss a pill, or vomit or have severe diarrhoea.
  • Minor side effects include mood swings, breast tenderness and headaches.
  • There is no evidence that the pill makes women gain weight.
  • There’s a very low risk of serious side effects, such as blood clots and cervical cancer.
  • The combined pill is not suitable for women over 35 who smoke, or women with certain medical conditions.
  • The pill does not protect against sexually transmitted infections (STIs), so using a condom as well will help to protect you against STIs.

How the combined pill works

The pill prevents the ovaries from releasing an egg each month (ovulation). It also:

  • thickens the mucus in the neck of the womb, so it is harder for sperm to penetrate the womb and reach an egg
  • thins the lining of the womb, so there is less chance of a fertilised egg implanting into the womb and being able to grow

Although there are many different brands of pills, there are three main types:

Monophasic 21-day pills

This is the most common type. Each pill has the same amount of hormone in it. One pill is taken each day for 21 days and then no pills are taken for the next seven days. Microgynon, Rigevidon, Brevinor, and Cilest are examples of this type of pill.

Phasic 21-day pills

Phasic pills contain two or three sections of different colored pills in a pack. Each section contains a different amount of hormones. One pill is taken each day for 21 days and then no pills are taken for the next seven days. Phasic pills need to be taken in the right order. Binovum and Logynon are examples of this type of pill.