Progesterone Pill

What is it?

  • A daily pill taken by mouth containing the hormone progesterone.

How does it work?

  • One pill is taken every day.
  • The hormone thickens the mucus at the entrance to the womb preventing sperm getting through and thins the lining of your womb preventing implantation of a fertilised egg. Some POPs also stop ovulation (eggs being released from the ovaries).

What’s great about it?

  • Very effective. If taken perfectly the pill is >99% effective – only 3 in 1000 women will get pregnant each year. However, pill users often don’t take it correctly (e.g miss pills) or consistently and such typical use means more women will become pregnant (9 in 100).
  • Periods may stop or become lighter or less frequent.
  • It can improve heavy or painful periods.
  • Its effect on fertility is rapidly reversible.
  • Can be used by women who cannot take oestrogen (COC/Patch/ring) e.g. overweight women.

What’s not so great about it?

  • No protection against sexually transmitted infections (STIs) - condoms advised.
  • It needs to be taken at the same time each day otherwise it may stop working. It can be difficult remembering to take the pill on time.
  • Periods may stop, be irregular, prolonged or more frequent. This may settle with time.
  • Can cause side-effects such as spotty skin, breast tenderness, or weight change but these should settle within a few months. Mood changes have also been reported.
  • Some women get ovarian cysts.
  • Needs a regular prescription from a health care provider.
  • Its effectiveness can be reduced if you vomit or have diarrhoea.
  • Some medications can stop it working.
  • If the pill fails and you become pregnant there is a 1: 10 chance it could be an ectopic

Where can I get it?

  • Sexual Health services.
  • Family planning clinics
  • GP practice