Clear, honest answers about oral contraceptive pills — written for you, not for a textbook.
You’ve probably heard of “the pill” — it’s one of the most widely used forms of contraception in the world. But with so much information (and misinformation) floating around, it can be hard to know what’s true. This leaflet gives you straightforward, evidence-based answers — no jargon, no scare tactics, just the facts you need to make the right choice for your body and your life.
This information is based on guidance from NICE (National Institute for Health and Care Excellence), the Royal College of Obstetricians and Gynaecologists (RCOG), and the NHS. Always talk to your doctor, nurse, or pharmacist before starting or changing contraception.
The oral contraceptive pill — usually just called “the pill” — is a small tablet you swallow once a day to prevent pregnancy. It contains synthetic (man-made) versions of the hormones that your body already produces naturally. These hormones are what prevent a pregnancy from happening.
It has been available in the UK since the 1960s and is one of the most thoroughly researched medicines ever made. Millions of women around the world use it safely every day.
No — these are very different things. The oral contraceptive pill is taken every day to prevent pregnancy before it starts. The morning-after pill (emergency contraception) is taken after unprotected sex and works differently. This leaflet is only about the regular, daily contraceptive pill.
The pill works in three clever ways — often all at once. First, it stops your ovaries from releasing an egg (this is called ovulation). No egg means no chance of fertilisation. Second, it thickens the mucus at the entrance to your womb (the cervix), making it very difficult for sperm to swim through. Third, it thins the lining of your womb, so even in the unlikely event that an egg was fertilised, it would not be able to settle and grow.
These three actions working together make the pill extremely effective when taken correctly.
Yes, there are two main types. The combined oral contraceptive pill (COC) — often simply called “the combined pill” — contains two hormones: oestrogen and progestogen. This is the most common type. The progestogen-only pill (POP), sometimes called “the mini-pill”, contains only one hormone: progestogen. It is often recommended for women who cannot take oestrogen, such as those who are breastfeeding, are over 35 and smoke, or have certain medical conditions.
There are many different brands within each type, and they vary in the dose and type of hormone they contain. Your doctor or nurse will help you find the one that suits you best — it can sometimes take a short while to find your perfect fit, and that’s completely normal.
💡 Good to know
If one pill doesn’t suit you, there are many alternatives. Don’t give up — speak to your healthcare provider about switching.
Taken correctly, the pill is one of the most effective contraceptive methods available. Here is what the numbers really mean:
Effective when taken perfectly (no missed pills)
Effective with "typical use" (real-life missed pills etc.)
The key word is consistency. Taking your pill at the same time each day and not missing doses keeps that number as close to 99% as possible. The mini-pill (progestogen-only) needs to be taken within a 3-hour window each day (or 12 hours for some types) to be fully effective.
You can start the combined pill at any time during your cycle. If you start it on day 1 to 5 of your period, you are protected immediately — no extra precautions needed. If you start at any other time in your cycle, you will need to use additional contraception (such as condoms) for the first 7 days.
For the progestogen-only pill (mini-pill), if you start on days 1 to 5 of your period you are protected straight away. If you start at any other time, you need extra contraception for the first 2 days.
💡 Simple tip
No — the idea that you need to have a “break” from the pill is a widespread myth with no medical backing. According to NICE guidelines, there is no need to take breaks from the pill for health reasons. You can continue taking it safely for as long as you wish, until you are ready to try for a pregnancy or switch to another method. Taking unnecessary breaks actually increases the risk of an unintended pregnancy.
It happens to the best of us — don’t panic. Here is what to do:
If you missed 1 combined pill (up to 24 hours late): Take the missed pill as soon as you remember, even if that means taking two in one day. You are still protected and do not need extra contraception.
If you missed 2 or more combined pills (more than 48 hours late): Take the most recent missed pill immediately and leave any earlier missed ones. Use extra contraception (like condoms) for the next 7 days, and consider emergency contraception if you had unprotected sex in the previous few days.
For the mini-pill: If you are more than 3 hours late (or 12 hours for some brands), take it as soon as you remember and use condoms for the next 2 days.
⚠ When in doubt
If you are unsure what to do after missing pills, call NHS 111, speak to your pharmacist, or check the patient information leaflet that came with your pills. Emergency contraception may be needed.
If you vomit within 2 hours of taking the combined pill, your body may not have absorbed it properly — treat it as a missed pill and take another one. If vomiting or severe diarrhoea continues for more than 24 hours, treat the situation as if you had missed a pill for each day of illness and use extra contraception. The same guidance applies to the progestogen-only pill.
Some women take the pill for years and feel absolutely no different. Others notice some changes, particularly in the first few months as their body adjusts. Common effects that often settle within 2 to 3 months include nausea (especially if taken on an empty stomach), breast tenderness, headaches, and light spotting between periods.
Some women notice changes in their mood or sex drive, though research shows this is not universal — and many women actually find the opposite: that relief from painful periods or pregnancy anxiety improves their wellbeing and libido.
📝 Remember
If side effects are bothering you, don’t just stop — talk to your doctor or nurse. Switching to a different pill or a different type of contraception may solve the problem entirely.
This is one of the most common concerns — and the evidence is reassuring. Large, well-designed studies have not found a significant link between the combined pill and weight gain. Some women may notice slight fluid retention in the first few weeks, but this usually settles. If you do gain weight after starting the pill, it is worth considering other lifestyle factors too. If weight changes are a concern, speak to your doctor — there are many contraceptive options to explore.
Absolutely — and this surprises many people. The pill is used for a wide range of health reasons beyond contraception. It can significantly reduce painful, heavy periods — for many women with conditions like endometriosis or fibroids, it provides life-changing relief. It often makes periods lighter, shorter, and more predictable.
The combined pill has been shown to reduce the risk of ovarian cancer and womb (uterine) cancer, with protection that continues for many years after stopping. It can also help with acne, reduce the symptoms of premenstrual syndrome (PMS), and ease the pain of ovulation (known as mittelschmerz).
💡 Not just contraception
Many women take the pill primarily to manage painful periods or endometriosis — and their doctors prescribe it for exactly that reason.
The combined pill does carry a small increased risk of blood clots (a condition called venous thromboembolism or VTE). To put this in perspective: in women who are not on the pill, around 2 in 10,000 women per year develop a blood clot. For women on the combined pill, this rises to around 5 to 7 in 10,000 per year — still a very small number. For comparison, pregnancy itself carries a much higher risk than the pill.
The risk varies depending on which type of combined pill you take. Your doctor will choose the most appropriate option for you, taking into account your personal and family medical history.
⚠ Know the warning signs of a blood clot:
sudden leg pain or swelling, shortness of breath, chest pain, or coughing up blood. If you experience any of these, seek emergency medical attention immediately.
This is a nuanced area, and it’s important to look at the full picture. The combined pill is associated with a small increase in the risk of breast cancer and cervical cancer. However, this increased risk is small, and it largely disappears within about 10 years of stopping the pill.
On the other side of the scales, the pill offers significant protection against ovarian and uterine (womb) cancer, and this protective effect lasts for decades after stopping. Overall, for most healthy women, the benefits outweigh the risks — but this is a personal conversation to have with your healthcare provider, who knows your full medical history.
The combined pill can cause a small rise in blood pressure in some women. This is why your blood pressure is checked before you are prescribed the pill and at regular follow-up appointments. If your blood pressure is found to be high, your doctor may recommend a different form of contraception. The progestogen-only pill is generally considered safer for women with blood pressure concerns.
Stop taking the pill and seek medical attention straight away if you experience any of the following:
The combined pill is not suitable for everyone, and that’s why it requires a prescription and a health check. You are generally advised not to use the combined pill if you smoke and are aged 35 or over, have a personal or close family history of blood clots, have migraine with aura, have high blood pressure that is not well-controlled, have had breast cancer, or have certain heart or liver conditions.
If any of these apply to you, do not be disheartened — the progestogen-only pill or a completely different method of contraception (such as a coil, implant, or injection) may be perfectly suitable and just as effective. There are many excellent options.
The combined pill is generally not recommended in the first 6 months of breastfeeding, as the oestrogen it contains may reduce your milk supply. The progestogen-only (mini) pill, however, is safe to use while breastfeeding and does not affect your milk supply or your baby. This makes it a popular choice for new mothers who are breastfeeding and wish to use hormonal contraception.
This is great news for anyone thinking about future pregnancy. Your fertility returns very quickly after stopping the pill — often within days or weeks. Most women have a normal period within 4 to 6 weeks of stopping, and your natural cycle usually re-establishes itself within 1 to 3 months.
There is no evidence that taking the pill for a long time makes it harder to conceive afterwards. In fact, RCOG confirms that long-term pill use does not cause infertility.
When you stop the pill, your body will return to its natural hormonal rhythm. For some women, periods quickly become regular again. For others — particularly those who had irregular or heavy periods before starting the pill — it can take a few months for a regular cycle to re-establish. Any symptoms that the pill was managing, such as pain or heavy bleeding, may return. If you have concerns, it’s worth talking to your doctor before you stop.
No — this is an important point. The pill is very effective at preventing pregnancy, but it offers absolutely no protection against sexually transmitted infections (STIs), including chlamydia, gonorrhoea, and HIV. The only contraceptive method that protects against both pregnancy and STIs is the condom — male or female. If you are not in a mutually monogamous relationship where both of you have been tested, using condoms alongside the pill is strongly recommended.
You can get the pill from your GP, a sexual health clinic, some pharmacies (which can supply it directly), or a family planning clinic — all free of charge on the NHS. You will usually be asked to return for a blood pressure check and a general review after about 3 months, and then once a year thereafter. These checks are for your safety and wellbeing, not a formality — so do keep them.
💡 You’re in control
If at any time the pill is not working for you — whether for medical or personal reasons — simply speak to your healthcare provider. Contraception is not one-size-fits-all, and you deserve to find what works best for you.
Sources & References
This leaflet is based on guidance from the National Institute for Health and Care Excellence (NICE), the Royal College of Obstetricians and Gynaecologists (RCOG), and the NHS.
It is intended as general information and does not replace personalised medical advice.
Last reviewed April 2026 · Always speak to a qualified healthcare professional before starting, changing, or stopping contraception · NHS.uk · NICE.org.uk · RCOG.org.uk