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A BASHH Guide to Condoms

Do condoms work?

Yes - for heterosexual (straight) couples and men who have sex with men (MSM), using condoms every time you have sex reduces the transmission of HIV and other STIs.

Condoms are thought to be almost 100% effective in preventing HIV transmission if used perfectly all of the time. In real life most people do not use condoms perfectly, or for every type of sex, so protection may be less than this. Condoms also reduce the risk of catching or passing on chlamydia, gonorrhoea, herpes, warts and syphilis.

Whilst they do help, no method is perfect, so using a condom cannot guarantee that you will not catch an STI.


Condom advice

  • Use a condom every time you have vaginal or anal sex to minimise the risk of transmission of HIV and other STIs.
  • Consider using condoms for oral sex, especially if you have lots of sexual partners.
  • Even if you don't use a condom every time, or for every type of sex, use one as often as possible - this is safer than not at all.
  • Even if you occasionally did not use a condom that does not mean it is not worth using a condom every time in future.


Which condoms should I use?

  • Use a condom that is within its use-by date and has the relevant safety markings (for example CE or UKCA markings) on its packaging. 
  • It is important to use the type of condom that best suits you and your partner.
  • Non latex condoms are a good choice for some men, but are a bit more likely to break than latex condoms.
  • Use non-latex condoms if you have a latex allergy (or if you are using creams or treatments that damage latex condoms).
  • Female condoms are at least as good as male condoms at preventing STIs.
  • You get better at using condoms the more you use them. Practising opening and using a condom alone, and in the dark, might make it easier to do when you have sex.


Does size matter?

Yes, with condoms size matters!

  • Make sure you or your partner use a condom of the right size.
  • Condoms are more likely to split if too tight.
  • The girth (thickness/width) of the penis may be more important than penis length.
  • Try a range of condom sizes (such as Trim, Standard, Large/XL and Superking/XXL) to find what fits you best, or measure round your erect penis using a strip of paper to find the correct diameter of condom for you.


How to use condoms

  • Open the packet carefully - don't use your teeth and avoid damaging the condom with your nails, jewellery or piercings.
  • Put the condom on before you start having sex and leave it on all the way through.
  • Remove all the air from the condom before putting it on
  • Hold the condom during withdrawal (pulling out)
  • Don't unroll it before putting it on
  • If you put it on the wrong way by mistake, use another one - don't just flip it over


Using condoms for anal sex

Ordinary condoms are no more likely than thicker condoms to break or slip off during anal sex.

Some people feel safer using thicker (‘Extra' or ‘Strong') condoms for anal sex, but there is no proof that they are any safer than regular condoms.

You can use female condoms instead of male condoms for anal sex: remove the ring at the end of the condom and place on the penis like a male condom.


Using lubricant with condoms

Anal sex

Put a water or silicon based lubricant (NOT an oil based one) all over the condom and inside the anus (but not inside the condom) before anal sex.


Vaginal sex

Lubricant can make vaginal sex more comfortable or pleasurable, but you do not need to use extra lubricant for vaginal sex routinely. Lubricant does not make sex safer and increases the chance that the condom will slip off.


More information:


BASHH Patient Information Leaflets