Combined oral contraceptive pill

What is it?

‘The Pill’ contains oestrogen and progestogen and can be started up to and including the fifth day of your period, protecting immediately against pregnancy. If started on any other day, another method of contraception must also be used for 7 days1.

Most combined oral contraceptives come in 21-pill and 28-pill packages.2 With the 21-pill pack, a pill is taken for 21 days followed by a 7 day break, when you are likely to have a withdrawal bleed similar to a natural period. The 28-pill pack, called everyday pills (ED) contains 21 tablets that contain hormones plus 7 tablets which may contain no hormones. These extra pills help act as a reminder to take your pill everyday.

The Pill needs to be taken at a regular time on each day for it to be effective. Different types of pills contain differing amount and type of hormones.

How does it work?¹

The two hormones in the combined pill, oestrogen and progestogen, have a similar effect to the hormones found in your own body and taken daily:

• Stop your ovaries from releasing an ovum
• Thicken the mucus of the cervix to act as a barrier to sperm
• Stop the ovum from settling by keeping the lining of the womb thin

How effective is it?¹

The Pill is more than 99% effective when used correctly

What are the benefits?¹

• Does not interrupt sex
• Lighter, less painful, regular bleeds
• For those who wish to become pregnant, the method is easily reversible
• Protects against cancer of the ovary, colon and womb
• Can help to reduce premenstrual tension
• Can reduce the risk of fibroids and ovarian cysts
• May help with acne

What are the drawbacks?¹

Temporary side effects at first include headaches, breast tenderness and mood changes. If these side effects do not stop within a few months, changing the type of pill might help.

• The Pill may increase your blood pressure
• It does not protect you against sexually transmitted infections, so you may need to use a condom as well
• Breakthrough bleeding and spotting is common in the first few months of pill use

Are there side effects?²

Side effects from combined oral contraceptives are usually due to the amount of oestrogen that the Pill contains. Today's low-oestrogen pills are designed to provide good effectiveness, with reduced side effects. When side effects do occur, they usually disappear after the first 1-3 cycles of pill use. Possible side effects include:

Short-term side effects

• Breakthrough bleeding
• Potential increase in the chance of breast tenderness, headaches and nausea
• Weight gain or loss
• Mood changes

Long-term side effects:

• May increase blood pressure
• Very small increased risk of blood clots
• Very small Increased risk of breast cancer / cervical cancer

You should not take the combined contraception pill if you are/have had any of the following:¹

• You might be pregnant
• Over 35 years old and stopped smoking less than a year ago
• Have had blood clots in any vein or artery
• Have had circulatory disease or a heart abnormality
• Suffer from migraines with aura (migraines from bright or flashing lights)
• Have diabetes complications or have had diabetes for over 20 years
• Have had breast cancer within the last 5 years
• Have active liver or gall bladder disease
• Take certain medications that interfere with the efficacy of the Pill
• Are obese

What do I do if I miss a pill?¹

Missed pills may make your Pill less effective. The chance of getting pregnant after missing a pill depends on how many and when you missed the Pill. If you miss 1 pill in your pack or you start the pack 1 day late, it is not a problem. Missing more than 1 pill, or starting the Pill more than 1 day late may affect your contraceptive cover. It is more risky to start the Pill packet late than miss more than 1 pill. This is because during the 7 day break your ovaries are not getting the effect from the Pill, so your ovaries might release an ovum. If you are not sure what to do, continue to take your Pill, use additional contraception, and seek advice.

What do I do if I want to become pregnant?¹

If you decide to try for a baby, it is best if you stop taking the Pill at the end of the packet. It can help to wait for 1 natural period before trying to get pregnant. Waiting means you can start pre-pregnancy care, such as taking folic acid and stopping smoking. It also allows the pregnancy to be dated more accurately.

1. fpa. Sex/sexual health – contraception – The combined pill

2. NHS direct. Health encyclopedia – combined contraceptive pill