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The pill

Revisado: 4 de octubre de 2026

Solo en inglés por ahora

The pill comes in two main types: combined and progestogen-only. Here is how each works, how well it protects, common side effects and who may need a different method.

Two main types

The combined pill contains two hormones, oestrogen and progestogen. The progestogen-only pill, sometimes called the mini pill, contains only progestogen, a hormone that acts like the body's own progesterone. Both types work mainly by stopping the ovaries from releasing an egg each month. You take the progestogen-only pill every day, with no break between packs. With the combined pill, you usually take 1 hormone pill a day for 3 weeks, and many packs then have a week without hormones. Each type, and each brand, has its own instructions, so read the leaflet in your pack.

How well it protects

If you take it correctly every day, either type of pill is over 99% effective. In real life, pills are sometimes missed or taken late, and typical use is about 91% effective. That means around 9 in 100 people using the pill for a year get pregnant. Being sick or having diarrhoea can also affect how well it works, and the pack leaflet explains what to do. The pill does not protect against sexually transmitted infections (STIs).

Missed or late pills

What to do depends on your pill, so check the leaflet or ask a pharmacist. As a general guide, if you miss one combined pill, take it as soon as you remember, even if that means 2 pills in one day. If you miss 2 or more in a row, take the latest one, carry on, and use condoms until you have taken 7 pills in a row. A progestogen-only pill counts as missed when it is more than 3, 12 or 24 hours late, depending on the type. If you had sex after a missed pill, ask about emergency contraception.

Common side effects

Bleeding between periods (breakthrough bleeding) and other changes to your bleeding are common in the first few months. Some people get headaches, mood changes or sore breasts, or feel sick or dizzy. The progestogen-only pill can cause spotting or bleeding between periods. There is no evidence that the combined pill makes you put on weight or changes your sex drive. If side effects still bother you after 3 months, talk to a pharmacist or doctor.

Rare but serious risks

The combined pill carries a small risk of a blood clot in the leg or lung. This is rare and affects up to 1 in 1,000 people using combined hormonal contraception. Very rarely, a clot can cause a heart attack or a stroke. Get help urgently if one leg becomes painful or swollen, often in the calf or thigh, or the skin there looks red or darker. Call your local emergency number if you also feel short of breath or have chest pain. The pill can slightly raise the risk of breast and cervical cancer, and it lowers the risk of womb, ovarian and bowel cancer.

Who may need a different method

The combined pill is not safe for everyone. You may not be able to take it if you smoke and are 35 or over, or are living with obesity. The same applies if you have had a blood clot, a stroke, heart disease or high blood pressure. Migraine with aura (warning signs before the headache), breast cancer, some liver and gallbladder problems, diabetes complications, or a close relative with a blood clot before 45 can also rule it out. If you are breastfeeding, wait until 6 weeks after the birth. Talk to a doctor, nurse or pharmacist if any of these apply. Logging each pill in Ciclo gives you a record to check if you are not sure whether you took one.

This is general information. Follow your pill's leaflet, and ask a pharmacist, doctor or nurse if you miss a pill or are unsure what to do.