Here are some key things you need to know about condoms.

Only use condoms with a BSI kite mark or CE mark Always choose condoms that carry the BSI kite mark or European CE mark, as these are recognised safety standards. Don't use novelty condoms, unless they carry the BSI kite mark or CE mark.

New sex, new condom Use a new condom every time you have sex.

The 30-minute condom rule If you're having a long sex session, change condoms after 30 minutes. Friction can weaken the condom, making it more likely to break or fail.

1 condom at a time Never use 2 condoms together, whether that's 2 male condoms or a female and a male condom. They'll rub against each other, and this friction can weaken them and make them more likely to break or fail.

Keep condoms cool Heat can damage condoms, so store them somewhere cool and dry.

Condoms don't last forever Check the expiry date on the packaging, as condoms don't last forever and may be past the point at which they work.

Safer sex on holiday Buy condoms before going on holiday to avoid problems with language and trying to find somewhere to buy them.

Don't use lotion or oils with condoms Don't use body lotions, moisturiser, massage oil, body oil, lipstick or any other oil-based product (such as petroleum jelly, or Vaseline) with latex, polyisoprene or lambskin condoms. This is because they can weaken the condom, making it less effective. Use plenty of water-based lubricant, such as K-Y Jelly (available from pharmacies), especially for anal sex.

Oral sex and condoms Using a condom (apart from lambskin condoms) during oral sex can help protect against sexually transmitted infections (STIs), including HIV and syphilis, and those that affect the mouth or throat, such as herpes, gonorrhoea and chlamydia. You could try using flavoured condoms for variety.

Don't put condoms down the toilet Wrap used condoms in a tissue or piece of paper and put them in a dustbin. Don't flush used condoms down the toilet.