The progesterone-only pill is usually used by women who can’t use a combined pill that contains oestrogen – for example if they find they have a negative reaction, or if they have high blood pressure or a history of blood clots.

Progestogen is the hormone that is released during a natural period and stops sperm from reaching an egg.

• As the pill, it’s 99 per cent effective if taken correctly and can make periods lighter, even causing them to cease altogether.
• Suitable for women over 35 (unlike the combined pill) and those who find oestrogen hormonal methods don’t work

• Change in hormones can result in mood swings, bloating, weight gain and headaches
• Must be taken at the same time every day – if you take it three hours late, it may not be effective
• Progestogen increases sodium loss and increases core temperature – so it still has an impact upon ability to reach high intensity and recovery
• Slightly higher risk of developing breast cancer than women not on the pill