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Unprotected sex

Michael Carter, Greta Hughson
Published: 25 September 2012

Unprotected sex is a term often used to describe anal or vaginal sex if a condom is not used.

HIV and sexually transmitted infections (STIs) can be passed on during unprotected sex. Unprotected penetrative (the insertion of the penis into the body of another person) anal and vaginal sex carries the greatest risk of STIs, however, infections can also be transmitted through oral sex (mouth to genitals), and oral-anal sex (mouth to anus), also called 'rimming.'

Using condoms (including female condoms) is a very effective method of preventing HIV and other STIs from being passed on during sex, but some people with HIV choose to have unprotected sex.

Unprotected sex with HIV-negative and untested people

If you are living with HIV, using condoms during sex with people who know that they are HIV-negative or are unsure of their HIV status will protect them against HIV and protect both of you from STIs.

There's a lot of debate about how infectious people with HIV are if they are taking HIV treatment and have an undetectable viral load. Most experts agree that when HIV treatment is keeping viral load under control, the risk of HIV transmission is reduced to a low level, but that some risk still exists.

The law is also an important consideration. In the UK (and in many other countries) a number of people have been sent to prison for passing HIV on to their sexual partners, after failing to tell them they had HIV. You should also be aware that in some countries you are legally required to disclose your HIV status to sexual partners. You can find out more about this subject at www.aidsmap.com/law.

Sometimes, couples who are 'serodiscordant' (one has HIV and one does not), choose to have unprotected sex because they want to have a baby. It's a good idea to talk to your doctor about this option, so that you and your partner can make sure you are as healthy as possible before trying to conceive.

Sex with other people who have HIV

Many people with HIV have unprotected sex with a partner who also has HIV.

However, If you have HIV and are having sex with another person who has HIV, there are some important considerations you should be aware of so you can make an informed decision about sex. These issues include:

  • Unprotected vaginal sex can result in pregnancy. There are other methods of contraception, apart from condoms, but it is important that you choose the right method for you. Some anti-HIV drugs interact with hormonal contraceptives, so make sure you discuss your choice of contraception with your HIV doctor. HIV can be passed on from a woman to her baby, but with the right treatment and care, the risk of this happening is very small. Talk to your HIV doctor, or someone else in your healthcare team if you are considering having a baby.
  • There have been a small number of cases of so-called 'superinfection' with a new strain or strains of HIV, which could be resistant to anti-HIV drugs. This could lead to the failure of treatments that might otherwise have been effective. This applies to both men and women. However, the number of recorded cases of superinfection is small. The cases have almost all involved people who were infected with HIV for less than four years and either were not on HIV treatment, or were taking a treatment break.

Bacterial STIs, such as gonorrhoea and chlamydia can be treated just as easily and successfully in most people with HIV as in people who are HIV-negative, provided that they are diagnosed and treated promptly. Some infections, if left untreated, can lead to infertility and in some cases damage to the internal organs. 

There are also viral STIs. Genital herpes and genital warts are not curable, even in people who are HIV-negative. Although both these infections will respond to treatment, they can reoccur and can be harder to control if you have a very weak immune system. Genital herpes is linked to an increased risk of HIV transmission, especially when ulcers are present. The viruses hepatitis A and  hepatitis B and (less easily) hepatitis C, can also be passed on sexually and can be more complicated in people with HIV. Hepatitis can cause liver damage which can limit HIV treatment options and make you very unwell in its own right.

There are vaccines for hepatitis A and B (but not C), which should be available at your HIV treatment centre. Gay men in particular are advised to be vaccinated against hepatitis A and B. After you have been vaccinated it is important to have your immunity to hepatitis A and B checked regularly, as the vaccines do not offer permanent protection. There's now good evidence that hepatitis C can be passed on sexually. Some HIV-positive gay men have been infected with hepatitis C after having unprotected sex.

Having an untreated STI increases the amount of HIV in the genital fluids, making HIV easier to pass on if you have unprotected sex.

It is recommended that all sexually active people have regular sexual health check-ups. Many HIV treatment centres have sexual health clinics attached, which in the UK offer free and confidential testing and treatment.

Contact NAM to find out more about the scientific research and information used to produce this factsheet.

This content was checked for accuracy at the time it was written. It may have been superseded by more recent developments. NAM recommends checking whether this is the most current information when making decisions that may affect your health.