How it works
The pill contains synthetic versions of estrogen and progestogen. Together they stop the ovaries from releasing an egg each month. They also thicken cervical mucus and thin the lining of the uterus.
People who can remember a daily pill and want control over their periods, provided they do not have risk factors that rule out estrogen.
How effective is it?
Typical use
93%
In real life about 7 in 100 people get pregnant in a year with typical use.
Perfect use
Over 99%
About 0.3 in 100 when used exactly as directed every time.
See how it ranks against every method in the effectiveness chart.
How to use it
Get it from a doctor, nurse, sexual health clinic, or in some places a pharmacist; they will check your blood pressure, weight, and medical history first.
Take one pill at around the same time every day. Depending on the pack, you may take a 7-day break or placebo pills, or take pills continuously with fewer or no breaks.
If you start within the first 5 days of your period, you are usually protected straight away; otherwise use condoms or another method for the first 7 days. Some brands have different rules, so check the leaflet.
If you miss pills, or vomit or have severe diarrhea, protection may be reduced; follow the instructions in your pack leaflet or ask a pharmacist, as you may need extra protection or emergency contraception.
You can stop at any time; it stops working soon after, so use another method if you do not want to get pregnant.
Pros and cons
Advantages
- Very effective when taken consistently.
- Usually makes periods lighter, more regular, and less painful.
- Lets you control the timing of bleeds or skip them, depending on the regimen.
- Can help with acne and premenstrual symptoms for some people.
- Reduces the long-term risk of cancer of the ovary, uterus, and bowel.
- Easy to stop, and fertility returns quickly.
Disadvantages
- Does not protect against sexually transmitted infections (STIs); use condoms as well for that.
- Needs to be taken every day, and missed pills reduce protection.
- Vomiting, severe diarrhea, and some medicines can stop it working properly.
- Small increased risk of blood clots, and a very small increased risk of stroke and heart attack.
- Linked with a small increased risk of breast and cervical cancer, which falls after stopping.
Effect on periods: Bleeding is usually lighter, more regular, and less painful, and some regimens let you skip bleeds.
Possible side effects
- Spotting or breakthrough bleeding, especially in the first 3 months
- Nausea
- Headaches
- Breast tenderness
- Mood changes
Who it may not suit
A clinician checks your medical history before you start. This list is not complete.
May not be suitable if
- You are 35 or older and smoke, or stopped smoking less than a year ago.
- You have migraines with aura.
- You have had a blood clot, or a close family member had one before age 45.
- You have certain heart conditions, high blood pressure, or have had a stroke.
- You have a high BMI (for example 35 or over), have had breast cancer, have certain liver or gallbladder conditions, or gave birth in the last few weeks.
Get medical help if
- You have pain or swelling in one leg, chest pain, or sudden breathlessness or coughing up blood, which can be signs of a blood clot; get urgent help.
- You have a sudden severe headache, problems with vision or speech, or weakness or numbness on one side of the body; call emergency services.
- You develop migraines with aura for the first time, or your headaches change.
- You think you might be pregnant or have missed pills and had sex.
Frequently asked questions
What should I do if I miss a combined pill?
It depends on how many pills you missed and where you are in the pack. Generally, one missed pill means taking it as soon as you remember, while missing two or more may mean you need extra protection or emergency contraception. Check your pack leaflet or ask a pharmacist.
Does the combined pill cause weight gain?
Research has not shown that the combined pill causes significant weight gain. Some people notice fluid retention or appetite changes, which often settle.
Is it safe to skip the pill-free break?
For most people, taking pills back to back to skip a bleed is safe, and UK and US guidance support flexible regimens. Spotting is more common, and you should follow the advice for your specific pill.
Can I take the combined pill if I get migraines?
If you have migraines with aura, the combined pill is usually not recommended because of a higher stroke risk. Migraines without aura may be fine, but a clinician should assess this.
How soon does the combined pill start working?
If you start within the first 5 days of your period, it usually works straight away. At any other time, use condoms or another method for the first 7 days; a few brands have different rules, so check your leaflet.
Sources
Reviewed 1 November 2026. We link to the guidance itself so you can check it.