A diaphragm or cap is put into the top of your vagina. It covers your cervix, which is the entrance to the uterus (womb).

The diaphragm or cap acts as a barrier to help stop sperm getting into your womb and fallopian tubes and reaching an egg.

A diaphragm or cap must be used either with contraceptive gel or with spermicide. Spermicide can be a gel, cream or foam. You add the contraceptive gel or the spermicide to the diaphragm or cap. It makes it hard for sperm to swim and also forms a chemical barrier to help stop sperm getting into the womb. Also see below – Where can I get contraceptive gel or spermicide?

If 100 people who could get pregnant don’t use any contraception, 80 to 90 will get pregnant in a year.

• If a diaphragm or cap is used perfectly every time you have sex, including using the correct size and using it with contraceptive gel or spermicide, then it’s about 78% to 84% effective at preventing pregnancy, depending on the type used. This means about 16 to 22 out of 100 diaphragm or cap users will get pregnant in 1 year.

• Most people don’t use contraception perfectly every time. If you don’t use a diaphragm or cap perfectly, it will be slightly less effective. About 17 to 22 in 100 diaphragm or cap users will get pregnant in 1 year, depending on the type used.

• Evidence suggests that diaphragms can be more effective than caps at preventing pregnancy.

• Caps may be less effective at preventing pregnancy in people who have given birth, because your vagina and cervix change shape during pregnancy and birth.

A diaphragm or cap may be less effective if:

• you use it without contraceptive gel or spermicide
• you have sex 2 hours or more after you put it in, without first adding extra contraceptive gel or spermicide
• it’s damaged
• it doesn’t cover your cervix completely
• it moves out of place
• it isn’t the right size
• you don’t add extra contraceptive gel or spermicide to your diaphragm or cap every time you have sex
• you put it in after you’ve started having sex
• you take it out too soon (less than 6 hours after the last time you had sex)

If any of these happen, or if you’ve had sex without using contraception, get advice about using emergency contraception.

• You only use it when you have sex
• You can put it in at a convenient time before you have sex. But add extra contraceptive gel or spermicide before having sex if it’s more than 2 hours since you put it in. Keep the diaphragm or cap in your vagina and use your finger or an applicator to add more gel or spermicide.
• It’s not affected by any medicines you’re taking
• Serious health risks are rare
• It’s suitable if you can’t use, or don’t want to use, hormonal contraception or a copper IUD
• It’s suitable if you or a partner are allergic to latex
• It’s reusable and can last for 1 to 2 years (depending on the type) before it needs replacing

• It’s not as effective at preventing pregnancy as hormonal contraception, a copper IUD or external (male) condoms
• You have to remember to use it correctly every time you have sex
• It needs to be available every time you have sex
• It must stay in for at least 6 hours after sex
• It can take time to learn how to use it
• It will not help protect you from sexually transmitted infections (STIs) so you may want to use condoms as well
• You can’t use it when you have a period – also see below – Can I use my diaphragm or cap during my period?
• You may need a vaginal examination when you first get a diaphragm or cap
• You may find contraceptive gel or spermicide messy
• You or a partner may not like the smell or taste of contraceptive gel or spermicide
• You or a partner may be sensitive to spermicide, if used. This may cause irritation or allergy. Most people can use contraceptive gel without any irritation
• A chemical in spermicide called nonoxinol-9 may increase the risk of getting HIV and other STIs – see below – Are there any risks? and Nonoxinol-9 is not in contraceptive gel
• Some diaphragm users may have an increased chance of getting a urinary tract infection (UTI)

Diaphragms and caps are safe for most people. Serious health risks are rare.

Spermicide (but not contraceptive gel) has a chemical called nonoxinol-9. In some people, this can cause irritation in the vagina which can put you at a higher risk of getting or passing on STIs including HIV.

It’s advised to avoid using a diaphragm or cap and to use condoms if you have a higher chance of getting or passing on HIV, for example if:

• You or a partner have more than one sexual partner
• You or a partner are living with HIV and not on effective treatment (effective HIV treatment reduces the amount of HIV in the body to such a low level that there is zero risk of the virus being passed to sexual partners; this is known as U=U or Undetectable equals Untransmittable)

Using a diaphragm or cap may increase your chance of getting an infection called toxic shock syndrome – sometimes called TSS. Toxic shock syndrome is extremely rare but very serious. Reduce the chance of toxic shock syndrome by:

• always washing your hands before putting in or taking out a diaphragm or cap
• not leaving it in place for longer than the recommended time

Signs of toxic shock syndrome can include:

• sudden high temperature
• aching muscles
• feeling shivery
• being sick or having diarrhoea
• a rash, which can feel rough like sandpaper
• feeling unwell, or like you have flu

If you have any of these signs and symptoms and think you may have toxic shock syndrome, take out your diaphragm or cap and get medical advice right away, for example by calling 111 (or Phone First in Northern Ireland).

Also see NHS information about toxic shock syndrome.

Most women and people with a vagina and cervix can use a diaphragm or cap.

A diaphragm or cap may not suit you if:

• you find it difficult to put in or place in the right position
• your cervix or vagina is an unusual shape
• your vaginal muscles can’t hold a diaphragm in place
• you don’t feel comfortable touching your vagina
• you’re sensitive or allergic to silicone, spermicide or contraceptive gel
• you can’t use the diaphragm or cap correctly and consistently

A diaphragm or cap may not be suitable if you have:

• a condition that makes pregnancy an unacceptable health risk
• have ever had toxic shock syndrome
• a higher chance of acquiring HIV
• a condition that affects your cervix (cap only)

If you have a higher chance of getting a sexually transmitted infection (STI), for example if you or a partner have more than one sexual partner, a diaphragm or cap with spermicide may not be the best choice for you unless you use condoms as well.

Diaphragms and caps are not as effective at preventing pregnancy as many other types of contraception. To compare how effective different methods of contraception are, also see FPA guide to contraception.

If a diaphragm or cap suits you, you can use it until after the menopause when contraception is no longer needed.

You can get a diaphragm or cap on prescription for free from:

• most contraception and sexual health clinics
• some young people’s services
• some GP surgeries

It’s also possible to buy a diaphragm or cap online or from some pharmacies. They come with instructions to help you learn to use them. It’s preferable to get advice from a trained healthcare professional about fitting and using the diaphragm or cap, even if you buy your own.

Always use your diaphragm or cap with either contraceptive gel or with spermicide.

• Contraceptive gel is available to buy over the counter at some pharmacies and online. In the UK, it’s sold under the brand names Contragel and Caya Diaphragm Gel. The gel contains lactic acid. Available research suggests that lactic acid gel is as effective as spermicide at preventing pregnancy.

• Contraceptive gel may be supplied for free at some sexual health clinics, but usually you’ll need to buy it.

• Spermicide is not available on prescription and may be difficult to buy in the UK. You may be able to buy it from some online pharmacies. It may be a gel, cream or foam.

When you first get a diaphragm or cap, it’s preferable to get it fitted by a trained healthcare professional, even if you buy your own.

A healthcare professional can check what size you need by feeling inside your vagina. They will help you learn how to put it in and take it out, and how to add the contraceptive gel or spermicide.

• Practise putting it in and taking it out before you rely on it for contraception. This helps you learn to use it correctly. It also gives you time and privacy to see if it suits you.
• While you’re getting used to the diaphragm or cap, do not rely on it to stop you getting pregnant. Use condoms or another method of contraception if you have sex.
• Try putting it in and checking that it covers your cervix.
• Use the contraceptive gel or spermicide as well to see how this feels.
• To find out if it’s comfortable for you and a partner, try having sex with the diaphragm or cap in place – but use another method of contraception as well. Then leave the diaphragm or cap in for at least 6 hours.
• Also see below:
  • How do I put a diaphragm in?
  • How do I put a cap in?

After practising with the diaphragm or cap for 1 to 2 weeks, it’s preferable to go back to your healthcare professional. Put the diaphragm or cap in before your appointment. The healthcare professional will check that it’s the right size, is in the right place and is covering your cervix.

You can find your cervix by inserting a clean finger into your vagina until you touch the top and can’t go any further. The cervix feels like the end of your nose.

If you’re using a diaphragm, you can also feel inside your vagina for your pubic bone. This is just in front of the cervix. The diaphragm will rest on the pubic bone. This helps keep it in place.

Diaphragms come with instructions. They may have video instructions which can be easier to follow than written instructions. Check the product information leaflet for a link to video instructions.

This guide can help you put in a diaphragm. The different types of diaphragm are all used in a similar way.

It’s preferable that you also get advice from a healthcare professional before using a diaphragm – see above – How do I learn to use my diaphragm or cap?

Wash your hands before putting in a diaphragm.

The diaphragm needs to cover your cervix. It’s helpful to feel your cervix before putting in the diaphragm – see above – How do I find my cervix?

You might squat, lie down, or stand with one foot up on a chair while putting your diaphragm in, like you would when putting in a tampon or menstrual cup. Choose the position that’s easiest for you.

• Hold the diaphragm with the inside of the bowl facing up.
• If using a Caya diaphragm, squeeze the diaphragm using the grip dimples on each side, to create a fold in the middle. Then squeeze about 1 teaspoon of contraceptive gel or spermicide along each side of the fold.
• If using a different diaphragm to Caya, put 2 small strips of contraceptive gel or spermicide inside the bowl. Each strip can be about 2cm long.
• For all diaphragms, you could also spread a little bit of contraceptive gel or spermicide on the edges. This may make it easier to put in.
• Squeeze the diaphragm between your thumb and fingers to fold it.

• Slide the folded diaphragm into your vagina backwards and upwards. The dome part should be facing down. This helps make sure that the diaphragm covers your cervix:

• The diaphragm is held in place by the vaginal muscles, the rim of the diaphragm and the pubic bone.
• Use a finger to feel for your cervix. If it’s covered, you should be able to feel it through the diaphragm.
• If the cervix is not covered, take out the diaphragm by hooking your finger under the rim or removal dome (if it has one) and gently pulling downwards, then try putting it in again.

Always add more contraceptive gel or spermicide before having sex if the diaphragm has been in place for more than 2 hours. Keep the diaphragm in your vagina and use your finger or an applicator to add more gel or spermicide.

Leave the diaphragm in for at least 6 hours after sex. If you want to have sex again during this time, always add more contraceptive gel or spermicide first. Keep the diaphragm in your vagina and use your finger or an applicator to add more gel or spermicide.

Caps come with instructions. They may have video instructions which can be easier to follow than written instructions. Check the product information leaflet for a link to video instructions.

This guide can help you put in a FemCap, which is the only brand of cap currently available in the UK. The different sizes of FemCap are all used in the same way.

It’s advised that you also get advice from a healthcare professional before using a cap – also see above – How do I learn to use my diaphragm or cap?

Wash your hands before putting in a cap.

The cap needs to cover your cervix. It’s helpful to feel your cervix before inserting the cap – see above – How do I find my cervix?

You might squat, lie down, or stand with one foot up on a chair while putting your cap in, like you would when putting in a tampon or menstrual cup. Choose the position that’s easiest for you.

• Hold the cap with the strap underneath and the narrower part of the cap at the top.

• Fill about one-third of the cap with contraceptive gel or spermicide. This is the part that will go against your cervix. Don’t put any contraceptive gel or spermicide around the rim (outer edge) as this may stop the cap staying in place.

• The side of the cap with the strap has space between the dome and the rim. Put some contraceptive gel or spermicide in this space.

• Squeeze the sides of the cap together and hold the cap between your thumb and first 2 fingers.

• Hold the cap with the strap underneath and the wider side of the cap pointing downwards and towards your back.

• Still squeezing it together, slide the cap into your vagina upwards and backwards as far as it will go.

• It needs to completely cover the cervix.

• It’s held in place by suction and supported by the sides of the vagina.

• Use a finger to feel for your cervix. If you can feel it, then it isn’t covered. Take the cap out by hooking your finger under the strap and gently pulling downwards. Then try again.

Always add more contraceptive gel or spermicide before having sex if the cap has been in place for more than 2 hours. Keep the cap in your vagina and use your finger or an applicator to add more gel or spermicide.

Leave the cap in for at least 6 hours after sex. If you want to have sex again during this time, always add more contraceptive gel or spermicide first. Keep the cap in your vagina and use your finger or an applicator to add more gel or spermicide.

If it’s in the right place, neither you or a partner should be able to feel the diaphragm or cap. If you can feel it or it’s uncomfortable, ask your healthcare professional to check the fit.

If it continues to be uncomfortable, consider trying a different type of diaphragm or cap or using a different method of contraception.

If it’s painful, stop using the diaphragm or cap and use a different method of contraception. Get advice from a healthcare professional.

Leave in your diaphragm or cap for at least 6 hours after the last time you had sex.

Wash your hands before taking it out.

If you’re using a cap, push your fingers against the centre of the cap to break the suction before trying to remove it.

Take out the diaphragm or cap by hooking your finger under the rim, the removal dome or the strap, if it has one, and gently pulling downwards and out.

You can leave in a diaphragm or cap for longer than 6 hours, but do not leave it in for longer than recommended in the instructions.

• For a diaphragm this is usually 24 hours after putting it in
• For a cap, this is usually 48 hours after putting it in

If you’ve reached the recommended time but you had sex less than 6 hours ago, wait until 6 hours after sex and then take it out as soon as possible after that.

Check the instructions that came with your diaphragm or cap for more information.

When you take out your diaphragm or cap:

• Wash it in warm water with a mild, unperfumed soap. Do not boil it and do not use disinfectant, detergent or other types of cleaning product
• Rinse it thoroughly
• Dry it with a soft, clean cloth or kitchen roll or leave to air dry
• Never put any type of powder on it
• Keep it in its case in a cool, dry place

To take care of it:

• Check it regularly for tears, holes or wrinkles by holding it up to the light and having a good look at it. You can also fill it with water to see if it leaks.
• Take care not to damage it with anything sharp, like fingernails or jewellery. If it’s damaged, do not use it. Throw it away and get a new one.
• Do not use silicone-based or oil-based lubes or other products with a diaphragm or cap. They could damage it. Water-based lubes and water-based vaginal moisturisers are safe to use.

If your diaphragm goes out of shape, squeeze it gently back into its circular shape.

Your diaphragm or cap may become discoloured. Don’t worry, this won’t make it less effective.

Never share your diaphragm or cap with anyone else.

Your diaphragm or cap will need replacing straight away if it gets damaged.

If it’s not damaged, it will usually need replacing after 1 to 2 years. Check the instructions that came with your diaphragm or cap.

No. Avoid using a diaphragm or cap during your period. It may increase your risk of getting an infection called toxic shock syndrome – also see above – Are there any risks?

If you have a bath, water may wash away the contraceptive gel or spermicide.

Do not have a bath during the first 6 hours after you’ve had sex. It’s fine to have a shower during this time.

The effect of swimming or water sports hasn’t been studied, but it’s likely to be small.

The manufacturers of the Caya diaphragm advise that it’s safe to go swimming before sex with the diaphragm in place.

If you’ve gained or lost more than 3kg (7lb) of weight, you may need a different size diaphragm or cap.

Talk to a healthcare professional for more information.

Yes, but wait until at least 6 weeks after the birth. If you have sex earlier than this, use a different method of contraception from 21 days after the birth. See Contraceptive Choices  – After a Baby.

If you used a diaphragm or cap before having your baby, check with a healthcare professional that it still fits before using it again. You may need a different size after giving birth.

If you used a diaphragm or cap before the miscarriage or abortion, check with your healthcare professional that it still fits before using it again. You can use a diaphragm or cap straight after a miscarriage or abortion if you were less than 12 weeks pregnant.

If you were more than 12 weeks pregnant, it’s advised to wait until 6 weeks after the miscarriage or abortion. Use another method of contraception during this time.

Once you have a diaphragm or cap that you’re happy with, you only need to see a healthcare professional about it if:

• You have any questions or concerns
• You have any pain or irritation when using it
• You want to replace it
• You gain or lose more than 3kg (7lb) in weight – you may need a different size
• You’ve recently been pregnant – you may need a different size
• You want to change to a different method of contraception