The combined contraceptive pill or ‘the pill’, as it’s often referred to, contains two synthetic versions of the hormones progestogen and oestrogen, which are produced naturally by your body.
Most combined pills contain the same amount of hormones in each pill, delivering a consistent dose of progesterone and oestrogen every day. These are called monophasic pills.
Some combined pills are known as “phasic” pills. These pills have different amounts of hormones every week, which mimic natural changes in your hormone levels throughout your cycle. For some women, this can lead to fewer or more manageable side effects, but they are a little trickier to use than monophasic pills.