What is the Pill?
The combined oral contraceptive pill—often just called “the pill”—contains artificial versions of the hormones oestrogen and progesterone, which are naturally produced in the ovaries.
At a Glance: The Combined Pill
- When taken correctly, the pill is over 99% effective at preventing pregnancy. Fewer than 1 in 100 people who use the combined pill correctly will become pregnant in a year. Other methods—like the IUD, implant, and injection—are even more effective.
- Typically, the pill is taken once a day for 21 days, followed by a 7-day break, during which a period-like bleed occurs. The next pill pack starts after the 7-day break, even if the bleeding hasn’t stopped.
- It’s important to take the pill at around the same time each day. Missing a dose, vomiting, or having severe diarrhoea can reduce its effectiveness and increase the chance of pregnancy.
- Some medications can also reduce the pill’s effectiveness. Always check with a healthcare provider if you’re taking other medication.
- The pill may also help with heavy or painful periods, premenstrual syndrome (PMS), or endometriosis.
- Common side effects include mood changes, nausea, breast tenderness, and headaches. There's no evidence the pill causes weight gain.
- There is a very small risk of more serious side effects, such as blood clots or certain cancers.
- The combined pill may not be suitable for people over 35 who smoke, or for those with certain medical conditions.
- The pill does not protect against sexually transmitted infections (STIs), so using a condom as well is recommended for STI protection.
How the Pill Prevents Pregnancy
The pill prevents ovulation (the release of an egg). It also:
- Thickens cervical mucus, making it harder for sperm to reach an egg
- Thins the womb lining, reducing the chance of a fertilised egg implanting
Although over 99% effective when used correctly, the pill can be less effective if taken irregularly. Some people may find it difficult to take it at the same time every day. Other contraceptive methods—like the IUD, implant, or injection—can be more reliable for some users.
Types of Combined Pill
There are many brands, but they fall into three main categories:
Monophasic 21-Day Pills
Each pill contains the same hormone dose. One is taken daily for 21 days, followed by 7 days off. Examples: Microgynon, Marvelon, Yasmin, Cilest.
Phasic 21-Day Pills
Pills contain varying hormone levels across the cycle. They must be taken in the correct order. Example: Logynon.
Every Day (ED) Pills
A pack contains 21 active pills and 7 inactive (placebo) pills. Taken daily for 28 days with no break between packs. Example: Microgynon ED.
Always follow the instructions that come with your pill pack. Ask a GP, nurse, or pharmacist if you’re unsure.
How to Take the Pill
21-Day Pills:
- Take your first pill marked with the correct day.
- Continue daily at the same time until the pack is finished.
- Take no pills for the next 7 days (you will likely experience bleeding).
- Start the next pack on the 8th day—regardless of whether you’re still bleeding.
Every Day (ED) Pills:
- Start with the first active pill in the pack marked “start.”
- Continue daily in the correct order until the pack is finished.
- You will bleed during the 7 inactive pills.
- Begin your next pack immediately after the last.
Starting the Pill
Most people can start the pill at any point in their cycle. You may need additional contraception when first starting, depending on timing.
- Starting on Day 1 of your period: You’re protected straight away.
- Starting on Day 5 or earlier: Usually still protected unless your cycle is shorter than 23 days.
- Starting after Day 5: You’ll need additional contraception (e.g., condoms) for 7 days.
If there’s any chance you’re already pregnant, take a pregnancy test 3 weeks after the last unprotected sex.
Missed Pills, Vomiting, or Diarrhoea
- If you miss a pill, it may reduce effectiveness. What to do depends on when and how many were missed.
- Vomiting within 2 hours of taking the pill? Take another one.
- Severe diarrhoea may also impact effectiveness—use backup contraception and check with a healthcare provider.
Who Can Use the Pill?
Most people can take the pill up to menopause, but it’s not suitable for everyone. Don’t use the pill if you:
- Are pregnant
- Are 35 or older and smoke or quit less than a year ago
- Have certain health conditions (e.g., blood clots, certain cancers, severe migraines)
A healthcare provider can help determine if the pill is suitable for you.
After Birth, Miscarriage, or Abortion
- After giving birth (not breastfeeding): Can usually start on Day 21.
- Breastfeeding: Wait until 6 weeks after birth.
- After miscarriage or abortion: Start within 5 days for immediate protection.
Advantages and Disadvantages of the Pill
| Advantages | Disadvantages |
|
Doesn’t interrupt sex |
Can cause temporary side effects like headaches or nausea |
| Regulates, lightens, and reduces period pain | May increase blood pressure |
| May reduce acne and PMS | Doesn’t protect against STIs |
| Lowers risk of ovarian, womb, and colon cancers | Linked to small risk of serious conditions (e.g., blood clots, breast cancer) |
| May protect against pelvic inflammatory disease and fibroids |
Interactions With Other Medicines
Some medicines reduce the effectiveness of the pill. These include:
- Rifampicin/rifabutin (antibiotics)
- Certain epilepsy medicines
- St John’s Wort (herbal remedy)
- Some HIV medications
Always consult a doctor, nurse, or pharmacist about any medicine you’re taking.
Risks
Blood Clots
Oestrogen may increase clotting risk, which can lead to deep vein thrombosis (DVT), pulmonary embolism, stroke, or heart attack. Risk is low but should be assessed by a doctor.
Cancer
There is a slight increase in the risk of breast and cervical cancers while taking the pill, but the risk returns to normal 10 years after stopping. The pill also reduces the risk of ovarian, womb, and colon cancer.
Where to Get the Pill
Contraception is free through the NHS in the UK. You can get it from:
- Some GP surgeries – talk to your GP or practice nurse
- Find your nearest sexual health clinic in Bexley
Coming off the pill
How quickly it leaves your system: The hormones from the pill will usually leave your body within a couple of days – no matter how long you have been taking the pill for.
How quickly you can get pregnant: This varies depending on when ovulation (releasing an egg) starts up again. It could be a matter of days or months depending on the person. Fertility levels should return quite rapidly, so use condoms or another method if you don’t want to get pregnant.
What happens to your periods: Talk to a doctor or nurse if after stopping the pill you have irregular periods or it’s taking a long time for your periods to start again.
What physical changes there might be: Everyone reacts slightly differently to coming off the pill. This is often temporary as your hormone levels self-regulate over the course of a few weeks or months. If symptoms persist or worsen, please see your doctor or nurse for help and advice.
If You’re Under 16
Services are free and confidential—even for those under 16. A healthcare professional won’t tell parents/carers unless there's a serious concern about safety or wellbeing, and they'll usually discuss this with you first.
Commonly asked questions:
‘Will the pill make me gain weight?’
There is no evidence of weight gain from the combined pill, but if you are concerned, speak with your GP or visit your nearest sexual health clinic.
‘Will the combined pill give me acne?’
The combined pill can have varying effects on acne; while it often helps improve skin condition, some individuals may experience initial breakouts. Speak with your GP if you have any concerns.
‘Will the pill lower my libido?’
Different contraception methods affect people in various ways. It is possible that the combined pill may increase or decrease your libido. If this happens, and you’re not happy, you can stop and try another form of contraception to find the best one for you.
‘Do you ovulate on the pill?’
Generally, you do not ovulate on the pill. The oestrogen in the pill stops your body from ovulating (releasing an egg) each month.