Stimulation of the man’s penis by his partner's mouth and tongue (fellatio, blow job)
Stimulation of the woman’s vulva by her partner's mouth, tongue and teeth (cunnilingus)
Stimulation of the area around the anus (rimming) by the partner's tongue (anilingus).
Are there any risks?
It is possible to catch infections by oral sex but, in general, the chances are probably lower than with penetrative sex. The risks also depend on whether you are the partner performing oral sex, or the partner who is having it done to them.
Risks to the partner performing oral sex
Gonorrhoea. It is quite easy to catch a gonorrhoea throat infection by performing oral sex on a man who has it. He will have some discharge from the urethral opening (the ‘pee hole’), and this discharge will be teeming with gonorrhoea bacteria. Unfortunately, the discharge is not always noticeable, so neither partner may be aware that he has the infection. Alternatively, he may have noticed a discharge previously, but may have assumed that the problem had cured itself.
Similarly, it might be possible to catch gonorrhoea throat infection by performing oral sex on a woman who has gonorrhoea.
Chlamydia. You can catch chlamydia in your throat by performing oral sex on a man who has it. A man who has a chlamydia infection may have pain passing urine and/or a discharge, or he may have no symptoms.
Warts. It is not a good idea to perform oral sex on a man who has genital warts. The warts may not be obvious – check around the edge of the head of the penis under the foreskin, and just inside the opening of the urethra (‘pee hole’). Although the risk is not great, it is possible to develop a wart on the roof of your mouth as a result of oral sex. The wart may take weeks or even months to appear. If you develop one, go to your local genitourinary medicine clinic.
Similarly, it is possible to develop a wart on your lips from performing oral sex on a woman who has genital warts. Again, if this happens, your local genitourinary medicine clinic is the place to go.
HIV. It is possible to catch HIV by oral sex. Although the risk is low, it is not absolutely safe, and oral sex with someone who might be HIV positive cannot be described as ‘safe sex’.
The body fluids of a person who has HIV (including semen and the natural fluids that lubricate the vagina) will contain the virus. Therefore HIV can infect the cells that line the mouth of the person performing oral sex, and then enter the bloodstream (Journal of Virology 2003;77:3470–6). The risk is likely to be greater when performing oral sex on a man than a woman. Withdrawing the penis before the man’s orgasm (ejaculation) would lessen the risk; however, when a man is sexually aroused, small amounts of semen leak out before ejaculation so infection could still occur.
Syphilis is uncommon in the UK, but is increasing. A study reported in the journal Communicable Disease and Public Health in 2001 found that many of the people infected were homosexual men who had oral sex without using a condom.
Mouth and throat cancer. Oral sex can lead to mouth or throat cancer, but the risk is tiny. The reason is that the genital area can be infected with type 16 human papillomavirus (HPV). This type of papillomavirus can cause mouth and throat cancers (New England Journal of Medicine 2007;365:1944–56).
Risks to the partner who is receiving oral sex
Herpes. Apart from being bitten, catching genital herpes from a cold sore on the face is the main risk. Cold sores are also infectious at the tingling stage before the sore has developed. If your partner has recurrent cold sores, he or she will recognize this tingling feeling, and should avoid performing oral sex until the sore has healed completely.
Chlamydia and gonorrhoea. In theory, it is possible to catch gonorrhoea or chlamydia by receiving oral sex from someone who has it in their mouth. Chlamydia and gonorrhoea in the mouth tends to be mainly at the back of the mouth (throat) and does not usually cause a sore throat or any other symptoms.
HIV. Contact between your genitals and the mouth of someone with HIV means that your genitals are in contact with their saliva, which will contain the virus. The amount of virus in the saliva would be very small and there would probably be a very low risk of infection, but it would not be absolutely safe.
Safe oral sex
Do not perform oral sex on a man who has a discharge, or has recently had one that was not treated.
Do not perform oral sex on anyone whose genitals look unhealthy or unclean.
If your partner has a cold sore on the face or lip, do not let him or her perform oral sex on you. Likewise, do not offer oral sex if you have a cold sore or think you might be getting one, or have any ulcers in your mouth.
Some experts say you should avoid mouth-to-genital contact unless you are very sure that your partner is HIV negative.
Avoid brushing your teeth beforehand, because this could open up cracks in the gums which would make it easier for infection (such as HIV) to enter.
Consider using condoms for oral sex. If you are concerned about infection during oral sex, but do not like the idea of condoms because of their off-putting rubbery taste, try flavoured ones. Textured, knobbed or ribbed condoms are not suitable for oral sex, because they can make the mouth sore.
Swallowing semen during oral sex is not harmful. The main risk of infection is in the mouth (see above). Swallowing semen is unlikely to increase the risk of HIV, because the stomach contains acid that destroys HIV.
‘Rimming’ (licking round the anus) is not to be recommended. The lower bowel contains many bacteria and viruses, which could enter the mouth, even if the anal area is washed beforehand.
Written by: Dr Margaret Stearn Edited by: Dr Margaret Stearn Last updated:
Monday, December 3rd 2012
Chlamydia is the commonest sexually shared infection. Click on the video below to find out what GP and comedian Dr Phil Hammond has to say about it.
Useful contacts for Oral sex
Click to see all the contacts that you may find useful in relation to oral sex
A problem shared is a problem halved: help others by sharing your frustrations or successes at tackling your health problem.
We have noticed that many of your queries are actually answered on the website, so please read carefully before submitting a comment. As all comments are moderated, there will be a delay before your comment appears. Please note that we cannot respond to individual requests for feedback.