The term ‘contraceptive pill’ refers to a number of different hormonal tablets taken to prevent pregnancy. Widely known as “the pill”, this is a popular and effective form of hormonal contraception. Some women also take the contraceptive pill to help regulate painful or heavy periods or to alleviate the symptoms of acne.
There are two main types of the contraceptive pill:
The combined contraceptive pill works to prevent pregnancy by affecting ovulation. It does this by suppressing the release of hormones from the brain which act on the ovaries to cause the release of an egg each cycle. In addition, the progestogen in the combined pill contributes to thickening the cervical mucus, making it more difficult for sperm to pass into the cervix.
The progestogen-only pill functions to increase the production and thickness of cervical mucus, which makes it harder for sperm to pass through the cervix into the uterus and fallopian tubes where fertilisation usually takes place. Progestogen-only pills suppress ovulation to varying degrees, depending on which type of progestogen-only pill is taken.
If you start taking either a combined pill or a progestogen-only pill within the first five days of your cycle (i.e. in the first five days after the start of your period), you will be protected from pregnancy right away.
If you start taking the pill at any other time, or if you have a shorter than normal cycle (23 days or less), you will need to use additional forms of contraception for a short time:
When used perfectly, both the combined pill and the mini-pill are more than 99% effective. This means that in 1 year, out of 100 women taking either pill, less than 1 would fall pregnant.
However, a lot of people do make mistakes when taking the pill. Therefore, in the population about 9 in 100 pill users will get pregnant each year, because the pill is not used perfectly according to instructions.
It is very important to follow the instructions included with your pill packet, because failure to do so may make your pill less effective. Remember to take your pill every day without a break, and to follow the instructions if you forget a dose. If you experience an episode of vomiting or diarrhoea, this may stop your pill from working, so use an additional form of contraception until you have recovered.
There is a range of different types of contraceptive pill available. These are:
The combined pill contains both oestrogen and progestogen. The oestrogen acts to prevent ovulation, stopping an egg from being released from the womb each month. Because of this, some women may feel more confident taking this than the mini-pill, which does not contain oestrogen. The combined pill may not be suitable for you if you are over 35, breastfeeding, overweight, a smoker, or if you suffer from certain medical conditions such as migraines or high blood pressure. Speak to your doctor if you are unsure if you are suitable for the combined pill.
The progestogen-only pill or mini-pill is an oestrogen-free alternative to the combined contraceptive pill and is suitable for most people.
For those who prefer not to use hormonal contraception, there is a range of barrier methods available, including male and female condoms and the contraceptive cap. These types of contraception prevent conception by creating a physical barrier between sperm and egg.
Some people want to use hormonal contraception but want to avoid the responsibility of remembering to take the pill each day. Alternative methods of hormonal contraception include the implant, the contraceptive injection, the contraceptive patch, the hormonal coil (IUS) and the vaginal ring.
The IUD (copper coil) is a hormone-free coil that is inserted into the uterus and releases copper, rather than hormones, to prevent conception.
If you are looking for a permanent form of contraception, you may also want to consider male or female sterilisation.
When they are taken according to the instructions on the packet, both the combined pill and the mini-pill are equally effective.
Your choice of which one to take is likely to come down to other factors, such as your age or weight, whether you smoke, or the side-effects you experience.
Some women experience unwanted side effects when taking the contraceptive pill, such as headaches and migraines, acne and mood swings. If you experience any of these whilst on the pill, talk to your GP or family planning nurse about alternative forms of contraception.
Most contraceptive pills are monophasic, which means that they contain the same amount of progestogen and/or oestrogen every day. Multiphasic and biphasic contraceptive pills (sometimes called phasic pills) contain different doses of hormones depending on which day they are taken on.
Most combined pills are designed to be taken for 21 days, followed by a seven-day break, known as the pill-free interval. During this break, you will usually have a withdrawal bleed, similar to a menstrual period.
Phasic pills vary the dosage of hormones throughout the month, and may also include a seven-day break. This idea is that by mimicking the woman’s natural cycle more closely, side effects may be reduced. It is important that the pills are taken in the right order, or they could be less effective. Examples include Logynon, TriRegol, Synphase and Qlaira.
Some contraceptive pills contain progestogen and/or oestrogen for the first 21 days, and then include seven days of “placebo” pills which do not contain any hormones. This usually results in a bleed that resembles a period.
Both contraceptive pills are generally safe, but there are some things you should know before you start taking it.
For the combined pill:
For the progestogen-only pill:
For many women, the benefits of taking the contraceptive pill outweigh the risks.
Hormonal contraceptive pills work well for many women, but others experience side effects. Everyone is different, but common side effects can include headaches, tender breasts, mood swings, acne, nausea and changes to your periods. These side effects are more likely to occur when you first start taking the pill and in many cases settle down after three months.
If you are experiencing side effects like headaches or nausea immediately after taking the pill, consider changing the time that you take it. By taking the pill just before bed, you may be able to stop the side effects from affecting your everyday life.
If these or other side effects are having an adverse effect on your life, you may want to speak to your GP or family planning practitioner about alternative forms of contraception.
The contraceptive pill isn’t suitable for everyone. The combined pill, which contains oestrogen, may not be suitable for those who:
It is important to discuss your suitability for the combined oral contraceptive pill with your doctor.
It’s important to speak to your doctor if you have any doubts about whether either of the contraceptive pills is a good choice for you.
Thrombosis or thromboembolism is another name for blood clots, which are often associated with taking the combined pill. These are rare but can be discussed in more detail with your GP to find you the most suitable contraceptive.
A review article in 2018 found that there was no clear evidence that hormonal contraception causes depression however it is widely acknowledged that mood changes can be a side effect of both the combined contraceptive pill and the progestogen-only pill.
More research is required in this area to establish if there is a causative link between taking contraceptive pills and developing depression.
Although research is ongoing to develop a male contraceptive pill, there is currently no such pill available for men.
While the contraceptive pill is more than 99% effective at preventing pregnancy when taken correctly, it is possible to get pregnant whilst on the pill. This is more likely if:
With typical use, taking into account that some women will experience the above problems, about 9 in every 100 women taking the pill will fall pregnant each year.
Yes, you must have a prescription in order to take the contraceptive pill in the UK. You can get this from your GP or from our online doctor.
Your pill may not work effectively if you do not take it at the same time each day. Follow the instructions on your patient information leaflet for information related to your particular type of contraceptive pill. You may need to use additional contraception for a short period of time, or you may require emergency contraception if you have had unprotected sex.