The combined pill

The combined pill contains two hormones: estrogen and progestin. This combination primarily works by consistently preventing ovulation (the release of an egg from the ovary) and also by thickening cervical mucus and thinning the uterine lining. Because it reliably stops ovulation, the combined pill often offers more predictable menstrual cycles and may have additional benefits like improving acne or reducing heavy, painful periods. Depending on the brand, you would either take one pill every day (if the pack contains sugar pills) or take 3 weeks on 1 week off to allow menstrual cycle flow.
 

The mini pill

In contrast, the mini-pill (progestin-only pill or POP) contains only one hormone: progestin. While some newer mini-pills (e.g., those containing desogestrel) can consistently prevent ovulation, older or "traditional" mini-pills primarily work by thickening cervical mucus to block sperm and thinning the uterine lining to prevent implantation. They may not always prevent ovulation, making timing of intake more critical (often requiring it to be taken within a very strict 3-hour window each day for older types, or 12 hours for newer ones, to maintain effectiveness). The mini-pill is often a suitable option for individuals who cannot take oestrogen due to health reasons (like a history of blood clots, migraines with aura, or breastfeeding) or who prefer to avoid it.

You need to ensure you take the pill at a similar time every day in order for it to work effectively. If you miss your pill, or have severe diarrhoea or vomiting, your pill may not work as well and you are at an increased risk of pregnancy.

If you are unsure, you should use additional contraception methods and contact your GP. If you are in need of the morning after pill, you can request treatment and read more information on our website.