Also called

  • Birth control, Family planning


  • Diaphragms act as a barrier method of contraception.
  • Other barrier methods include male and female condoms. 
  • Diaphragms need to stay in the vagina for at least six hours after sex.
  • Diaphragms do not give protection from sexually transmissible infections (STIs). The best way to lessen the risk of STIs is to use a condom with all new sexual partners.
  • For a diaphragm to be effective, you need to use it correctly, every time.
A diaphragm acts as a barrier method of contraception. It fits inside a woman’s vagina and covers the cervix (entrance to the uterus or womb) to stop sperm from meeting and fertilising an egg. Other barrier methods include male and female condoms. 

What is a diaphragm?

A diaphragm is a soft, shallow cup made of silicone. In Australia the one-size diaphragm is sold as Caya®. It is used with a special gel (jelly-like material, sold as Caya Gel®). 

How effective are diaphragms?

If used correctly every time you have sex, diaphragms are 86 per cent effective at preventing pregnancy. If used incorrectly, for example not inserting properly before sex or removing too soon after sex, they may only be 82 per cent effective.

What stops diaphragms from working?

A diaphragm might not work if it is: 

  • not inserted correctly
  • used without the gel
  • taken out less than six hours after sex
  • torn
  • past its use-by date.

How do I use a diaphragm?

To use a diaphragm, place a teaspoon of gel in the cup of the diaphragm, then put the diaphragm inside your vagina so it covers the cervix (opening to your uterus). 

Insert the diaphragm up to two hours before having sex, and leave it in place for at least six hours after sex. Do not leave the diaphragm in place for longer than 24 hours.

Before you use it, you can ask a doctor or nurse to check that the diaphragm fits well and that you are inserting it correctly. Diaphragms are the wrong shape for about one in seven women. The doctor or nurse can provide advice about how to insert the diaphragm comfortably. Caya® also provides a video with instructions about how to use the diaphragm.

How does a diaphragm work?

The diaphragm and gel work as a barrier to prevent sperm from passing through the cervix into the uterus. The sperm die off quickly in the vagina.

Where can I get a diaphragm?

You can buy a diaphragm from some pharmacies, family planning clinics and online. 

What is good about diaphragms?

The benefits of diaphragms are:

  • You can insert them hours before having sex.
  • They have little or no side effects.
  • You can buy them without a script.
  • They are a choice for women who do not want to use hormonal contraception. 

Are there any side effects from using a diaphragm?

Possible side effects for a small number of users can include: 

  • irritation of the vagina or penis
  • increased risk of bladder infection.

Can diaphragms cause any serious health problems?

Rarely, use of a diaphragm might cause toxic shock syndrome.

When is a diaphragm not a good option?

A diaphragm might not be a good option if you:

  • are prone to bladder infections
  • gave birth six weeks ago or less – because the size of diaphragm required may change as the uterus returns to normal size
  • are unable to feel if your cervix is correctly covered by the diaphragm. 

Speak to a doctor or nurse for advice.

What if I forget to use my diaphragm?

You may need emergency contraception if you had sex without using your diaphragm and did not use other contraception (check with your doctor, nurse or pharmacist).

What happens if I get pregnant while I’m using a diaphragm?

It is safe to continue the pregnancy (and stop using the diaphragm) or to have an abortion.

Can I use a diaphragm after I’ve had a baby?

You should usually wait six weeks after having a baby to start using a diaphragm. 

What else should I know about diaphragms?


  • do not protect you from STIs
  • should be checked carefully for holes
  • usually last around two years.

Where to get help


More information

Sexual health

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This page has been produced in consultation with and approved by: Family Planning Victoria

Last updated: November 2019

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