The contraceptive pill has hit the headlines several times in recent months. We have seen increasing numbers of young women shying away from the pill in favour of alternative contraception methods, such as the IUD, condoms and the rhythm method – with many talking to the papers to discuss the unpleasant side effects they have experienced.
More recently, we’ve heard about new research surrounding the “male pill”, a form of contraception for men, which comes in the form of a tablet (taken once a day) and works by suppressing the hormones associated with sperm production (1). According to the latest trials, it is safe and effective as a form of contraception, which means it may be made available relatively soon.
For many women, of course, the traditional birth control pill remains the most convenient and accessible form of contraception. If you’re considering switching your contraception, or if you’d like to begin taking the pill for the first time, it’s worthwhile researching the different types of contraception and how they work.
The first thing to know is that there are many different types of birth control pill, and that they work in different ways depending upon their active ingredients.
The Combined Pill
The most commonly used contraceptive pill is the combined pill. This type contains synthetic versions of the female hormones oestrogen and progesterone, and helps to prevent pregnancy in three ways:
- by preventing ovulation
- by thickening the cervical mucus, making it harder for sperm to enter the uterus
- by thinning the lining of the uterus to reduce the chance of a fertilised egg implanting
When used correctly, the combined pill is over 99% effective (2). Correct use involves taking your pill exactly as instructed; this normally means that you will take one pill every day for 21 days, before having a break of seven days. Monophasic combined pills such as Microgynon all contain the same hormones in the same doses, which means you don’t have to take them in a specific order. Phasic combined pills such as Logynon contain different doses of hormones, which means they must be taken in a specific order. Some varieties of the pill, such as Microgynon ED, are taken every single day; 21 pills contain hormones and seven contain inactive pills. This type of combined pill must be taken in a specific order.
The synthetic oestrogen contained in the combined pill is associated with a slightly increased risk of blood clots, which means it will not be suitable for certain women. It can also cause side effects such as breast tenderness and mood swings; to avoid these side effects you can try switching to a low-oestrogen combined pill.
Learn more about the combined pill at the NHS site.
The Progestogen-Only Pill
The progestogen-only pill (or “mini pill”) is a contraceptive pill that does not contain oestrogen. Because it only contains synthetic progesterone, it can be used by women who cannot take oestrogen.
The progestogen-only pill is over 99% effective when taken correctly; with “typical use” it is about 92% effective (3). Some women find that the mini pill is more difficult to take than the combined pill. This is because many types have to be taken within the same three-hour window every day (others, such as Cerazette, have a 12-hour window). The mini pill also differs from the combined pill in that it must be taken every single day without a break.
One disadvantage of taking the mini pill is that it can disrupt your periods. Many women experience spotting between periods and an irregular cycle; some even find that their periods stop altogether.
Learn more about the progestogen-only pill at the NHS site.
Different Active Ingredients
Though all contraceptive pills fall into one of the two categories listed above, it’s worth noting that different types within those categories will contain different versions of the hormones.
The mini pill Cerazette contains desogestrel, while the mini pill Noriday contains norethisterone. Both ingredients are synthetic forms of progesterone, but they work in slightly different ways. Mini pills containing desogestrel have a 12-hour window in which they can be taken; mini pills containing norethisterone only have a 3-hour window.
Because different pills contain different hormones in different amounts, you may have to try several different varieties before settling on one that works for you.