Caps & Diaphragms

A Contraceptive Diaphragm or cap is a soft silicone circular dome that can be inserted into the vagina before sex to prevent pregnancy.

It works by covering the cervix so that semen can’t get to the womb to fertilise an egg.

Caps are smaller than diaphragms, but they work in exactly the same way as diaphragms.

Like all contraceptive methods other than condoms, caps and diaphragms do not protect against sexually transmitted infections.

The Contraceptive Diaphragm or cap must be put in before you have sex and must remain in place for at least 6 hours after sex - it should then be removed and washed, it can be reused.

They create a barrier preventing semen from getting to the woman’s egg. You should also use a spermicide (a gel that kills sperm).

The Contraceptive Diaphragm or cap is around 92-96% effective when used correctly, meaning around 4 to 8 in every 100 women who use a diaphragm or cap became pregnant over a 1 year period.

Contraceptive Diaphragms and caps come in different sizes for different people, so you need to be fitted for one by a trained doctor or nurse.

You will be shown how to fit it properly, it may take some time and practice before you get used to using it.

You should visit your doctors surgery or sexual health clinic and ask about using a Contraceptive Diaphragm or cap. You can find your nearest sexual health clinic here.

  • No major health risks
  • Only needs to be used when you have sex
  • You’re in control of your contraception
  • Needs to be left in for at least 6 hours after sex
  • Not as effective as some other methods of contraception
  • Takes time to learn how to use it
  • Some people find it may interrupt ‘the mood’ when having to pause foreplay to put it in
  • Does not protect against sexually transmitted infections (STIs)
  • Latex and spermicide can cause irritation
  • It takes some time to learn how to use it
  • If you lose or gain weight or have a baby or abortion you may need to be fitted for a new sized diaphragm or cap