Combined Pill

The combined contraceptive pill is over 99% effective at preventing pregnancy when it's taken correctly. This is one of the main reasons women choose to use it. The effectiveness rate falls if you don't follow the guidelines, for example missing a pill or starting a new pack late.

For 99% effectiveness you should take the pill every day at the same time without fail and only take a seven-day break between packets (from most combined pill brands).

There are many different types of combined pill all made by different manufacturers. The ingredients vary but all work the same way. The three types of combined contraceptive pill are:

• Monophasic pills - 21-day pill which is the most commonly prescribed type of contraception. You take one pill for 21 days and then have a seven-day break. During this break, you are likely to have withdrawal bleed.
• Biphasic pill - 21-day pill that contains different amounts of hormone. These must be taken in the right order to be effective. The pills are marked with a colour-coded strip.
• Triphasic / Every day (ED) pills - 28 day pill containing seven inactive pills. You must take these in the right order. You should continue straight to the next packet as soon as you finish the 28 pills without the usual break.

Pregnancy occurs when a sperm fertilises an egg. A woman's hormones tell her ovaries when to release an egg. During this time she is fertile. The combined pill alters hormones so:

• The ovaries do not release an egg each month
• Cervical mucus is thickened so that sperm cannot pass through
• The womb lining is thinner so a fertilised egg can't implant there

It does this by releasing small amounts of oestrogen and progesterone – the natural sex hormones. These tell the body what to do.

It is simple to take the pill. They are small so that you can swallow them easily without water.

It's easiest to start your first packet of pills on the first day of your period for immediate protection. You can begin the combined pill at any point in your cycle but should use barrier contraception for seven days to allow the hormones time to work.

• Monophasic pills - There are taken for 21 days (three weeks) at a time. At the end of the pill strip, you take a seven-day break and have a withdrawal bleed. After seven days you start the next strip.
• Biphasic pills - These are taken in a specific order. The order is specified on the pill strip. You should not change this order as the pill contains different amounts of hormones. Take a seven-day break as per the monophasic pill.
• ED pills - If you take every day (ED) pills you need to follow the order indicated on the strip. You won't take a break from the pills, but the final seven are dummy pills and you are likely to have a withdrawal bleed.

You should always start the next strip on day eight, even if you are still bleeding.

It is possible to delay your period by taking the second pack straight away (with ED pills you should skip out the final seven) but it's not recommended that you take more than three packets without a break.

Missing contraceptive pills can lead to pregnancy, but forgetting is common. You should always take your pill each day. If you are forgetful it may be wise to set an alarm as a reminder or consider a less regular form of contraceptive such as the patch, vaginal ring or implant.

Here's what to do if you forgot your daily pill or you forgot to start the next strip on time:

You are less than 24 hours late: Take the pill straight away. You are still covered against pregnancy.

More than 24 hours late: Take the last missed pill and then your next pill at the correct time – you may take two pills close to one another. Leave any other missed pills and use barrier contraception for seven days. If there are less than seven pills left move onto your next packet without a break.

If you have vomiting and diarrhoea within two to three hours of taking your pill it won't have time to absorb. Take another pill, but if you continue to be ill you will need to use barrier contraception for seven days after you stop being unwell.

It is highly unlikely you will fall pregnant when you use the combined pill correctly. If you are uncertain at any point it's safest to use additional barrier contraception for seven days.

If you've had unprotected sex in the missed timeframe, you may fall pregnant. Consider emergency contraception which can be taken up to five days after unprotected sex but is more effective the sooner you take it. Emergency contraception works by delaying ovulation.

There are some women who are not suited to the combined pill - this is why it's a prescription only medicine. If you do or have any of the following you should not take the combined contraceptive pill.

• If you are pregnant
• If you smoke and are over 35
• If you stopped smoking over a year ago and are over 35
• If you are overweight
• If your current medications cause a contraindication
• If you have or have had a blood clot
• If you have heart disease including high blood pressure
• If you experience migraines with visual disturbances
• If you've had breast cancer
• If you have gallbladder or liver disease
• If you have been diabetic for over 20 years or have diabetes with complications

You may be able to take the combined pill if you have one of the following:

• You smoke or have quit in the past year
• You are overweight
• You have migraine
• You have high blood pressure
• You've had a blood clot or stroke
• You have a close relative who experienced a blood clot under 45 years of age
• You've been immobile for a period of time

The pill can be affected by other medications including some antibiotics, some antifungals, St John's Wort, some epilepsy medicines, barbiturates and anti-HIV drugs. Always tell your doctor or pharmacist if you are taking or have recently taken these medications.

Side effects of the combined pill

The combined pill is generally well tolerated but it can produce some side effects. The majority are mild and pass after a few months. If they don't speak to your doctor about swapping to an alternative combined pill as another may suit you better.

• Breakthrough bleeding
• Nausea
• Diarrhoea
• Rash
• Acne
• Breast tenderness
• Headaches
• Weight gain
• Missed periods
• Mood changes
• Changes in sex drive
• Visual problems with contact lenses
• High blood pressure

Very occasionally the pill can cause serious side effects with greater ease. This may lead to a blood clot. It also slightly raises the risk of breast cancer and may raise the risk of cervical cancer although this may be due to unprotected sex. Rarely the combined pill causes an allergic reaction.

Combined pill and pregnancy

If you want to conceive you should stop taking the pill. Your fertility won't be affected and you may fall pregnant straight away.

After giving birth you can start the combined pill 21 days after, but if you are breastfeeding you should wait because the combined pill slows down milk production. If you start taking the pill after 21 days post birth you will need to use additional barrier contraception for seven days.

If you are looking for a form of contraception and think the combined pill is for you, speak to your doctor about the pros and cons. Not all women are able to take the pill but your doctor will be able to advise if it suits your circumstances. If not, there are many other options available. Further Sources