Combined pill vs progestogen-only pill (mini pill): how they compare

The combined contraceptive pill is a type of hormonal contraception that contains the hormones oestrogen and progestogen. The NHS says it prevents pregnancy by stopping the ovaries releasing an egg each month. The progestogen-only pill, also called the mini pill, contains progestogen alone, a hormone that works in a similar way to progesterone, and the NHS says it also prevents pregnancy by stopping the ovaries releasing an egg each month.

There are three kinds of progestogen-only pill: the traditional pill, the desogestrel pill and the drospirenone pill. The brands and exact pills available differ, so check the packet and leaflet.

The combined pill is not suitable for everyone. The NHS says you may not be able to take it if you live with obesity or are aged 35 or over and smoke, and it may not be suitable if you have had blood clots (or a family member had them under the age of 45), narrowed or blocked arteries or a stroke, a heart problem or high blood pressure, migraines with aura, breast cancer, gallbladder or bile duct problems, liver cancer or severe cirrhosis, or complications due to diabetes.

The progestogen-only pill may not be suitable if you have ever had cardiovascular disease, a stroke, a liver condition such as cirrhosis, breast cancer or a kidney condition. Because it contains no oestrogen, the NHS says it is suitable for many people who cannot take oestrogen, and it can be started straight after giving birth and is safe while breastfeeding. A doctor, nurse or pharmacist will check which is appropriate for you.

The combined pill is taken either as an everyday (ED) pill with dummy pills, or as a 21-day pill with a 7-day break. You usually have a bleed like a period during the dummy pills or the break, and some people use a tailored regime with shorter or fewer breaks. If started in the first 5 days of your cycle you are protected straight away; otherwise use extra contraception for 7 days.

The mini pill is taken every day with no break between packs; you start a new pack the next day. If started on days 1 to 5 of the cycle, traditional and desogestrel pills protect immediately; otherwise extra contraception is needed for 2 days. For the drospirenone pill the NHS says to use extra contraception for 7 days unless started on day 1.

Both types can be affected by some medicines and herbal remedies. The NHS lists medicine for TB, epilepsy or HIV, griseofulvin, lamotrigine and St John's wort as ones to ask about.

For the combined pill, the NHS says bleeding between periods or changes to periods are common in the first few months, and that some people report headaches, mood changes, nausea, dizziness and sore breasts. There is no evidence that it makes you put on weight or changes your sex drive. A small number get high blood pressure. The risk of a blood clot is very small, affecting up to 1 in 1,000 people using combined hormonal contraception. It can slightly increase the risk of breast and cervical cancer, which goes back to normal 10 years after stopping, and can lower the risk of womb, ovarian and bowel cancer.

For the mini pill, the NHS says it has few side effects, but periods can become lighter, more frequent or stop, with spotting between periods. Some people report acne, mood swings, weight gain or changes to sex drive, but the NHS says there is not enough evidence to say these are caused by the pill. Ovarian cysts may develop; they are not dangerous and usually go away. There may be a link with breast cancer, but the evidence is limited and any increased risk is very small.

The decision usually turns on health history and preference: whether oestrogen is safe for you, whether you are breastfeeding, whether you want regular predictable bleeds or are happy with an unpredictable pattern, and how reliably you can take a pill at the same time every day. A GP, practice nurse, pharmacist or sexual health clinic can talk through the options and how both compare with other methods of contraception.