Contraception – the contraceptive pill
Written by Dr David Delvin, GP and family planning specialist

Is the Pill popular?

© NatMags - the Pill
The Pill is a tablet containing two female hormones – an oestrogen and a progestogen.
If you’re thinking of going on the Pill, you’ll be joining a band of about 100 million women worldwide who use this method.

How many women take it in the UK?

In the UK, there are about 3.5 million women who take the Pill. This is roughly one in three of all females of reproductive age.

The Pill has always been a bit controversial. Although it is now 55 years since it was first used (in Puerto Rico in 1956), there are still occasional 'Pill scares' – when newspaper headlines trumpet the dangers of Pill taking.

However, the fact that it remains so staggeringly popular does indicate that for huge numbers of women, the slight risks are outweighed by the benefits.

Is the Pill safe?

Did you know?
More than 100 million women worldwide use the contraceptive pill.
Basically, yes. But very occasionally, it can have serious side-effects.

However, recent news about Pill safety has been remarkably good.

The Royal College of General Practitioners has produced (2010) an important report, which revealed the fact that Pill-users have a 12 per cent reduction in their risk of developing cancer.

The researchers studied 46,000 women over a period of 40 years and found that those who had taken the Pill were less likely to die of cancer, heart disease or stroke.

The report also found that breast cancer rates appeared to be the same in women who have used the Pill, and women who haven’t. This finding goes some way towards diminishing previous fears about the Pill and breast carcinoma.

Only a very tiny number of women should not take the Pill, because they have serious medical conditions.
Nevertheless, most doctors don’t think that the Pill should be ‘dished out’ to absolutely everyone, without any need for a preliminary chat.

So when you want to start on the Pill, you should see a doctor (or family planning nurse) and have a short check-up.

This is partly to see if you have any risk factors – especially smoking – that would make you more liable to deep vein thrombosis (DVT), heart attacks or strokes.

Another important factor the doctor will be looking out for is obesity.

In May 2011, leading authority Anne Szarewski told a meeting of GPs that being overweight is 'the single most significant risk factor' for thrombosis on the Pill. She said that Pill-taking women whose body mass index (BMI) is 30 or more had almost 24 times the average risk of thrombosis.

At your first visit, quite apart from assessing risk factors, the health professional can explain to you exactly how to take the Pill and can answer any queries you've got.

Once you're on the Pill, what then?

You should return to the surgery or clinic for occasional 'Pill checks'. In Britain, they are usually done at six-monthly or yearly intervals.

These visits are very brief, and generally all the nurse or doctor does is ask you whether you’re having any problems with the Pill, ensure that you haven’t developed any ‘risk factors’ in the last six months and check your blood pressure (and possibly weigh you).

A lot of people still think that you have to have a vaginal examination and a smear test before going on the Pill or at subsequent visits, but this is no longer true.

What is the Pill?

The Pill is a tablet containing two female hormones – an oestrogen and a progestogen. This is why it's often called the combined Pill.

Various oestrogens and progestogens are used in the many different types of Pill that are available.

There are currently 28 brands on the market in Britain. Six new ones have recently been introduced, and one of these is being marketed on the basis of its ability to shorten periods. However, this is actually a welcome property of nearly all combined Pills.

The two hormones stop you from ovulating (producing an egg) each month. And if you don't ovulate, you won't get pregnant.

In addition, the hormones thicken the secretions round your cervix, making it more difficult for sperm to get through. Also, they make the lining of your womb thinner, so that it’s less receptive to an egg.

Is the Pill the same as the mini-Pill?

Pill versus mini-Pill
The two are not at all the same. The Pill contains two hormones; the mini-Pill only one. The mini-Pill has fewer side-effects but is also less effective.
No. The mini-Pill is not a low-strength version of the ordinary combined Pill. It’s a completely different product because it contains only one hormone instead of two. This makes it 'milder' and freer of side-effects, but also less effective.

Also, it doesn't control the periods in the same way that the ordinary Pill does.

Adverse effects of the mini-Pill can include breast discomfort, headache, dizziness, weight changes and spots on the skin.

For a full list, read the package leaflet, or talk to your nurse or doctor.

However, it is a very good method – especially for breastfeeding mothers, for over-35s, and for those who don't want to take (or can't take) the combined Pill.

How effective is the Pill?

It's very effective indeed, which is why so many millions of women rely on it.

If you take it exactly as prescribed, its effectiveness is likely to be almost 100 per cent.

Put it another way: let’s say that 100 women use the Pill for a year and that all of them never forget to take a tablet. It’s likely that not a single one of them will get pregnant.

In contrast, if they were all relying on the condom instead, probably about two to five of them would become pregnant. And if they used no contraception at all, perhaps 20 to 40 of them would fall pregnant!

So the Pill is just about the most effective method of contraception there is, apart from sterilisation.

How do you take it?

In the UK, you’re given a pack that usually contains 21 pills, and you take one every day for three weeks. At the end of those three weeks, you break for a week. During those seven days, you'll have your period.

If you wish, you can take seven 'dummy' tablets during the week's break. Brands that have seven dummy tablets are called 'ED' ones. ('ED' just means 'every day'.)

It's stopping the Pill at the end of the 21-day pack that brings on the period.

After the week's break, you start on your next packet. So it's 'three weeks on and one week off' throughout the year.

If you want to, you can set your mobile phone so that it beeps at the same time every day, to remind you to take your Pill.

Note: one newly-introduced Pill, called Qlaira is different from all the rest because the makers have decided that you should have hormones on 26 out of the 28 days of your cycle (and then two dummy tablets).

But how do I get started?

Go to a GP or a family planning clinic to see the doctor or nurse, and discuss risk factors and possible side-effects and get a prescription.

In Britain, it's now the practice to take your first-ever Pill on the first day of your period.

If you do this, you should be protected immediately – so you can have sex whenever you like.

Practices vary in other countries, and their Pill packs may contain more than 21.

In the USA, it's extremely common for women to be given packs containing 28 tablets – but seven of which are 'dummies'.

What are the good points about the Pill?

The Pill has now been shown to have certain major health advantages:

  • it usually abolishes period pains

  • it makes periods shorter

  • it makes them lighter.

Because of this, you are less likely to become anaemic.

If you have acne, the Pill should usually improve it – but not always.

The Pill is useful if you want to delay having a period for a special occasion, such as a holiday. By taking two packets back-to-back without a week's break, you can avoid having your period at an inconvenient time.

In addition, it decreases your chances of getting certain cancers (though it increases the risk of others).

But can't it give you a lot of side-effects when you start?

Yes. During the first few packs of the Pill, many women get minor, passing side-effects, such as:

  • headaches

  • nausea

  • breast tenderness

  • slight weight gain

  • slight 'spotting' of blood between the periods.

These side-effects usually go away after the first few packs. If they don’t, it's easy to get rid of them by simply switching to another brand.

What about serious side-effects?

There's no doubt at all that the Pill can occasionally cause serious problems like:

  • deep vein thrombosis (DVT) or clotting (this is now thought to be slightly more common in women who are taking Pills containing the progestogens desogestrel and gestodene)

  • heart attacks

  • strokes.

Fortunately, these events are rare. But they are much more likely to happen if you have certain 'risk factors', which include:

  • being a smoker

  • having a family history of thrombosis or some similar illness (say, if your mother had a heart attack or a deep vein thrombosis at 40)

  • being severely overweight

  • being diabetic (though quite a few non-smoking diabetics do use the Pill, under careful supervision)

  • having high blood pressure

  • having a high cholesterol level (hypercholesterolaemia)

  • having a past history of phlebitis (vein inflammation) or thrombophlebitis

  • being immobile for a while (especially when having a surgical operation).

There are other risk factors, for instance making a very long journey in a plane or a cramped car seat. Your doctor or family planning nurse can give you more details.

The risk is now known to be greater in the first year of taking the Pill. But it also increases a little as you get older, which is why many women come off the Pill some time after the age of 35.

However, the Family Planning Association (FPA) is currently stating that women without risk factors can take the Pill up to age 50.

Varicose veins

Many people have the idea that 'you can't take the Pill if you have varicose veins'. This isn’t true.

However, in recent years it has become clear that severe problems with varicose veins are a contraindication to the Pill.

But if you just have mild and superficial varicose veins, it's quite likely that your doctor will be willing to prescribe a low-dose Pill for you – provided that you have no other risk factors.

Familial blood factors

It's now clear that certain blood-clotting abnormalities that run in many families make you more liable to clotting.

The best-known of these is Factor V Leiden. If you have this, we suggest you go for another form of contraception.

Hughes' syndrome

In the last few years, it's become evident that a lot of women have something called Hughes' syndrome (anti-phospholipid syndrome, or APLS).

This blood disorder predisposes them to serious blood clotting. If you have Hughes' syndrome, you should definitely not go on the Pill.


In the early part of this century, new research showed that women who have severe migraine and use the Pill run an unacceptable risk of having a stroke.

Official advice in the 2011 edition of the British National Formulary (BNF) is that you can use the Pill 'with caution' if you have ordinary migraine.

But if you have migraine with 'aura' (which means odd 'warning' symptoms in any part of the body), you should avoid the contraceptive Pill altogether.

The BNF also states that women who have any increase of headache frequency on the Pill should tell their doctors.

Whether or not you have migraine, if you develop symptoms, such as severe headache, eye disturbances, numbness, paralysis, deafness, speech difficulties or fits while on the Pill, you should STOP taking it immediately, and ask your doctor to refer you to a neurology expert.

Fortunately, such alarming occurrences are rare.

Does age make a difference?

Yes. The Pill is extraordinarily safe for young women in their teens or 20s who have no risk factors (such as smoking). But when you get to the age of 35 or 40, the chances of having a thrombosis (clot) are starting to increase.

In practice, there are some women in their 40s who take the Pill, and the FPA currently believes this to be safe.

But as the years go by, there's more and more reason to switch to the mini-Pill or to some other method of contraception, such as sterilisation or vasectomy for your man.

What about cancer?

Did you know?
The Pill can increase the risk of some cancers and reduce the risk of others. Ask your doctor for advice.
The Pill does affect your risk of certain types of cancer – and when you first decide to go on it, you should be told about this.

But it's important for you to realise that the Pill actually reduces your chances of getting some cancers – while it increases the risk of others.

As far as we know, the Pill reduces your chance of getting:

  • cancer of the ovary

  • cancer of the womb (endometrium)

  • possibly bowel cancer – a 60 per cent reduction in risk has been claimed, though this is still not proven.

The Pill slightly increases your risk of getting:

Be 'breast aware'
Check your breasts regularly for lumps or anything odd, particularly as you approach middle age, which is when breast cancer starts becoming common.
  • cancer of the cervix

  • a very rare form of liver cancer

  • possibly breast cancer – but see above.

Does anything make the Pill less likely to work?

Yes. These things make it less effective:

  • forgetting Pills – especially at the beginning or end of a pack

  • having diarrhoea and/or vomiting (a common holiday risk)

  • taking certain anti-epilepsy drugs, including phenytoin (eg Epanutin) and carbamazepine (eg Tegretol). It has been agreed that the Pill should NOT be taken by women who are on the antiepilepsy drug lamotrigine (Lamictal).

  • taking the antibiotics rifampicin (, Rimactane) or for tuberculosis (TB) or other infections.

  • taking certain anti-HIV medicines, including ritonavir (egNorvir)

  • taking the morning-after pill called EllaOne (ulipristal acetate). You'd be wise to use extra precautions for two weeks if you are prescribed this as emergency contraception, for example if you've missed Pills. (The emergency contraceptive called Levonelle that you can buy over the counter contains a different ingredient and doesn't make the Pill less effective.)

  • taking the popular herbal remedy St John's wort while you are taking the Pill. It reduces the effectiveness of the oral contraceptive, and you may get 'spotting' of blood.

You used to be advised to use extra precautions, such as a condom, if you were prescribed a course of antibiotics like tetracyclines and Amoxil (amoxicillin).

This was because there was a theory that antibiotics could interfere with the Pill. But there has never been any clear evidence of this.

In February 2011, the Faculty of Sexual and Reproductive Healthcare of the Royal College of Obstetricians and Gynaecologists issued new guidance about taking ordinary antibiotics while on the Pill.

They stated that 'additional precautions' (such as condoms) are no longer considered necessary because the latest evidence suggests that ordinary antibiotics do NOT reduce the effectiveness of the oral contraceptive.

During 2011, this new advice has been resisted by some GPs, who have written in to medical publications claiming that they remembered cases in which women became pregnant when taking antibiotics while on the Pill.

So at present, you might still find that your family doctor wants you to use extra precautions while you are using an antibiotic.

It's generally agreed that if a course of antibiotics gives you diarrhoea or makes you sick, you do need to use extra precautions. Follow the instructions for diarrhoea and vomiting in the leaflet that comes with your Pill.

If a doctor wants to prescribe any drug of any kind for you, always tell him or her that you're on the Pill.

What if I miss a Pill?

Try not to! Of course people do inevitably miss Pills; it's only human nature.

If you miss only one Pill, you'll probably be OK. Take it as soon as you remember – and then take the next one on time (even if that means you’re taking the two of them at the same time).

If you want to be super careful, you could avoid sex for the next seven days – or take extra precautions.

However, if you're more than 12 hours late in taking the Pill, avoid sex for the next seven days – or take extra precautions. And consider taking the 'emergency contraceptive' – see below.

Missing more than one Pill is quite risky – particularly near the beginning or end of a packet. To avoid pregnancy, follow the advice on the pack leaflet strictly.

To be frank, the 'missed Pill advice' in these leaflets is pretty complicated. If you're in doubt:

Does the Pill reduce sexual desire?

Many experts believe that any reduction of desire is likely to be psychological in origin, and perhaps attributable to the woman being with the wrong partner – or at least a partner who does not make proper efforts to romance her and to give her adequate foreplay.

However, it does seem that a few women may have a reduction of desire because of their reaction to the hormones in the Pill.

In 2010, a study from the University of Heidelberg claimed that lack of libido is more common in women who are on the Pill than in those who use other methods.

In practice, many family planning doctors report that women who are on the Pill become more relaxed about sex, because they've been relieved of the fear of unwanted pregnancy.

So which Pill should I choose?

Regrettably, very few women do actually choose their own brand of Pill.

The choosing is mainly done by doctors or nurses. (The main exception to this occurs when a woman asks to go 'on the same Pill as my friend' – or 'the same as my Mum'.)

Unfortunately, some doctors who don't know much about contraception do tend to pick Pills more or less at random.

If you want a more informed choice, go to a doctor who has training in family planning.

I think you should ask for:

  • a low-dose Pill

  • a 'second-generation' Pill.

The reason for preferring a second-generation Pill is that the ones that came immediately after them in the late 1980s ( third-generation Pills) carry a minutely increased risk of thrombosis.

Also, at the end of April 2011, the British Medical Journal published research which suggested that Pills that contain the progestogen called drospirenone carry a slightly higher risk of clotting in the veins. However, statistically that risk remains low.

At present, the only contraceptive Pill available in Britain which contains drospirenone is Yasmin. But very popular through much of the world is a brand called Yaz. It's similar to Yasmin, but it contains less oestrogen.

In September 2011, the respected US health watchdog called the Food and Drug Administration (FDA) warned that there might be an increased risk of blood clots with Pill brands that contain drospirenone.

Nevertheless, the danger of vein thrombosis for women who are on low-dose Pills and have no other risk factors is small.

To put it into context:

  • Every year around 60 out of every 100,000 women who are pregnant will have a blood clot.

  • In women taking a 'second-generation' Pill, such as one containing levonorgestrel, a clot may occur in around 15 women out of every 100,000 each year.

  • In women taking a 'third-generation' Pill containing desogestrel or gestodene the risk is around 25 in every 100,000 women.

  • Pills containing drospirenone probably have a similar risk to these.

Clearly with all types of Pill the annual risk is less than the risk of getting a thrombosis while you're pregnant.

I strongly advise you not to pay any attention to newspaper stories or broadcasts that suggest any particular brand of Pill is wonderful' or ‘better than all the rest'. These tales usually originate from the PR companies employed by the manufacturers.

Useful numbers for Pill information

  • England, Scotland & Wales: Family Planning Association (FPA) helpline: 0845 122 8690.

  • Northern Ireland: FPA helpline: 0845 122 8687.

  • If you're under 25: Brook Advisory Centres: 0808 802 1234.

  • To find a family planning clinic, call NHS Direct on 0845 4647.

Other people also read:

Choosing a contraceptive: the most popular types of contraception.

Contraceptive injections: how do contraceptive jabs work?

Contraception – chemical methods: how do you use them?

Contraceptive implants: what are the side-effects?

Last updated 24.10.2011

Back to previous page

The materials in this web site are in no way intended to replace the professional medical care, advice, diagnosis or treatment of a doctor. The web site does not have answers to all problems. Answers to specific problems may not apply to everyone. If you notice medical symptoms or feel ill, you should consult your doctor - for further information see our Terms and conditions.

© Copyright 1998-2011 - All rights reserved

Express Repeat Prescriptions
Ask our Pharmacist
Store Locator
Contact Us

FREE P&P on all orders over £40 and all York Fitness equipment, standard P&P is £3.95. All private prescription items have a minimum order value of £5.00.