Combined contraceptive pill side effects
The combined contraceptive pill, often just referred to as 'the pill', is a very effective and arguably the most popular method of contraception. It releases synthetic oestrogen and progesterone that prevents pregnancy in three ways:
- It prevents the release of an egg through ovulation
- It thickens the mucus in the cervix making it near impossible for sperm to reach the egg if one is even produced
- It changes the lining of your uterus so the egg cannot attach itself to be impregnated
If taken correctly, the combined contraceptive pill is 99% effective. This means that in one year of taking the pill only one in 100 women will become pregnant.
Common and uncommon side effects
The combined contraceptive pill is well tolerated for the vast majority of women, however there are some common and uncommon side effects to be aware of when considering it as a method of contraception. Below are the side effects as listed by the US National Library of Medicine:
|Common side effects||Uncommon side effects|
When considering the term "common" with medication, this can be somewhat misleading as only a minority of women taking the combined pill will experience these side effects, and these tend to be temporary and mild in nature during the first few months of starting the medication.
Doctors will advise you to continue taking that particular combined contraceptive for up to three months by which point these side effects should have subsided considerably or disappeared altogether.
Rare side effects
There are some rare but potentially dangerous side effects associated with taking the combined pill.
The pill and blood clots
The oestrogen in the pill can make your blood clot more willingly. If blood clots do form, you could develop clots in your legs (a condition known as deep vein thrombosis) or a clot in your lungs (a condition known as a pulmonary embolism). These conditions can lead to stroke or heart attack.
A large scale study of two GP Databases in the UK was published in the British Medical Journal in 2015. It analysed the incidence of blood clots amongst those taking oral contraceptives across 1,340 GP Practices. It found that while the pill did increase the risk of blood clots threefold over baseline, it was still considered a rare side effect, with the increase being six in 10,000 blood clots in women taking the pill.
The pill and cancer
There is ongoing research into a link between taking the combined pill and a slightly higher chance of developing breast cancer, cervical cancer and a rare liver cancer, however this is an extremely minimal amount. In fact, according to the NHS, the pill can offer you some protection against developing other cancers such as ovarian cancer, colon cancer and endometrium cancer.
Cancer Research UK reported how short-term use seems to have little effect, but if taking the combined pill for five years or longer, you can double your risk of developing cervical cancer compared to women who don't take the pill. This risk falls again once you stop taking the pill and after ten years, the additional risk has disappeared. Similarly, with your increase risk of breast cancer, after ten years of stopping the pill the increased risk vanishes.
How to prevent the risk of side effects?
Certain lifestyle, age factors and underlying conditions can make you more susceptible to experiencing side effects. To prevent the risk of side effects, it's important to disclose all relevant information about your medical history when seeking a prescription. If you are identified as being at risk, there are numerous alternative contraceptive methods available to you. Your doctor can advise you on the best choice for you.
The combined pill is not suitable, due to the higher change of experiencing side effects, if you are, have or had:
- Over 35 years of age
- A smoker or have been a smoker in the last 12 months
- Very overweight
- Had a blood clot
- Any heart abnormalities or conditions
- High blood pressure
- Experience severe migraines
- Breast cancer
- Gallbladder or liver disease
- Diabetes with complications
Dealing with combined pill side effects
The most common side effects of taking the combined pill are headaches, mood swings, nausea and breast tenderness. These are usually temporary and will disappear within the first few months of use. Breakthrough bleeding is also common in the first few months. If any of these symptoms persist you should speak to your doctor, as another pill or brand may be more suitable for you.
If you notice any symptoms of the rare or more serious side effects, you should seek medical advice immediately. You should also speak to your doctor if your circumstances or health change and you now fall into one of the risk categories above. For example, if you develop high blood pressure or if you start smoking, you may need to stop taking the combined pill.