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Getting HIV from Oral Sex

Illustration by Édouard-Henri Avril of fellatio scene

Illustration by Édouard-Henri Avril of fellatio scene

Getting HIV from Oral Sex

What you need to know:

  • It is possible but extremely rare. The risk is much lower than anal or vaginal sex.
  • Scientific Data on HIV transmission in Oral Sex is not strong.
  • The type of Oral Sex that carries the highest risk is Receptive Fellatio.
  • Ejaculation, Gum Disease, Poor Dental Hygiene, Ulcers in the mouth and the presence of blood can increase the risk.

Oral sex refers to contact of the mouth to the ano-genital region.

It includes:

  • Receptive Fellatio (using your mouth on your partner’s penis)
  • Insertive Fellatiio (inserting your penis into your partner’s mouth)
  • Anulingus (using your mouth on your partner’s anus)
  • Cunnilinugs (using your mouth on your partner’s vagina)

While every one of these oral sex acts have case reports suggesting that they are possible, the only one with enough evidence to estimate a risk is Receptive Fellatio.

Therefore, it is accepted by most experts that this is the highest risk of all sex acts.

What exactly is the risk of contracting HIV from Oral Sex?

Unfortunately, no one knows for sure.

Most experts would agree that risks are extremely low.

Factors that increase the risk of transmission are:

  • Mouth Ulcers
  • Gum Disease
  • Use of Crack-Cocaine
  • Presence of blood (e.g. during menses)
  • High HIV Viral Load
  • Ejaculation

There have been many studies done on the transmission of HIV in oral sex. The vast majority concluded that oral sex in itself is NOT a risk factor for HIV transmission.

Click here for HIV Testing FAQ

There were however a handful of studies that found oral sex to be significantly associated with HIV infection. These studies focus on MSM (men-who-have-sex-with-men), CSWs (commercial sex workers) and people from lower socio-economic groups with a higher incidence of poor oral hygiene and mouth sores.

What serves for more scary reading are the case reports. Bear in mind that case reports are not as scientifically or statistically significant or important as clinical studies.

That said, there have been many case reports on possible Oral transmission of HIV. More notable cases include:

  1. Female to female transmission of HIV via oral sex
  2. A man who was bitten by a HIV +ve patient while trying to help him during a seizure

Studies conducted in San Francisco and London in 2000 and 2001 amongst MSM indicated that 6% to 8% of HIV +ve cases were believed to be cause by oral sex. Note that this does NOT mean the risk of getting HIV from oral sex is 6% to 8%.

Positive OraquickSo what exactly is the risk of getting HIV from oral sex?

No one really knows. A systematic review done in 2008 concluded that there was insufficient data to precisely estimate the risk. In my opinion, there are so many variable factors that there is really no way to accurately estimate the risk anyway.

However, everyone would agree that the risk is less than penetrative sex which has been estimated to be anywhere between 1% and 0.01%. So what we can say at this point in time is that the risk of contracting HIV via oral sex is less than this.

The only type of oral sex where there was any kind of risk estimation at all was receptive fellatio (the partner using his mouth) amongst MSM. The magic number given to this per-act-risk is 0.04%. Even then, some experts believe that this risk was over estimated because it was calculated from very complex mathematical models.

What is in saliva that kills HIV?

In 2008, a Swedish research team discovered that HIV –ve people produced antibodies in their saliva that can ‘kill’ the HIV virus. This provided an explanation as to why HIV transmission via oral sex is so low.

Another study found that the concentration of saliva is so low (i.e. hypotonic) that it ‘kills’ the white blood cells that carry the HIV virus. There was an experiment done in the lab (not on live patients) to show that if the volume of semen is high enough, it makes the overall environment closer to the concentration of cells (i.e. isotonic) and therefore increases the chance of cell survival and as a result increases the risk of HIV infection. This may explain why ejaculation is thought to increase HIV risk in oral sex.

There was also a study that suggested that a chemical found in saliva called Mucin can also inactivate the HIV virus.

The Burden of Scientific Proof

The real problem is that there have not been any good quality studies on HIV and Oral Sex. Most are based on interviewing HIV +ve patients on their sexual practices. So there is a problem of ‘recall bias’ (i.e. they forgot or their lying).

Furthermore, most studies involve relatively few participants. Since the incidence of HIV from oral sex is so low in the first place, many studies did not even have a single case of HIV transmission so were unable to estimate the risk in anyway.

So far in the studies that have been done, the estimated risk of contracting HIV from oral sex is either zero or really close to zero. So close to zero that physicians like myself find it hard to counsel patients who are concerned about getting HIV from oral sex. On the one hand, we do not want to tell them with absolute certainty that they are not at risk, on the other hand, we do not want to unnecessarily play up the risk leading to unwarranted anxieties, tests and treatments.

Why is it so difficult to get good data on HIV Transmission in Oral Sex?

We can all appreciate that medicine is never black and white. And almost nothing is 100% certain. Medical knowledge is gained from scientific study and statistical analysis. Once something is termed ‘statistically significant’ we generally tend to accept it as truth or fact. However, it also means that a small but definite number or people will fall outside of this ‘statistically significant’ majority. Also, it is often very challenging if not downright impossible to conduct scientific studies of enough quality and depth to reach a conclusion. Take our topic for example; we want to find out if HIV can be transmitted via oral sex. The best thing we can do is round up a million HIV positive women from around the world, make them perform oral sex on a million HIV negative men and determine if any of the men caught HIV. Then do it all over again this time with a million HIV positive men and a million HIV negative women. Then do it all over again with men performing oral sex on men and again with women performing oral sex on women. Even if somehow we manage to conduct this impossible and ethically questionable experiment, and somehow the number of people who caught HIV was absolutely zero, one can always say ‘what if the one million and one person would have been the one to catch HIV?’ Conversely, if one person out of this million couples does contract HIV, then we would have to come to the conclusion that HIV can be transmitted by oral sex. Right? Wrong. We have to take into consideration the possibility that there was a confounding factor. For example maybe this person already had HIV but was in the window period and so happened to be diagnosed only after the experiment. Which then opens up a whole Pandora’s box of ‘what ifs’. What if there was an ulcer on the lips? Ulcer on the gums? Sore throat? Cut on the lip? Dry cracked lip? A sore on the penis? Warts on the vulva? False negative HIV tests? False positive HIV test? Etc etc. The list is endless. You can see now why it is virtually impossible to reach a definitive conclusion and make a statement as strong as ‘HIV cannot be transmitted by oral sex’. This then leads to all the great authorities on HIV, infectious disease and public health coming to the same conclusion. ‘There is a possibility HIV can be transmitted via oral sex but this is rare.’ This statement very nicely covers all possible legal loopholes. E.g. ‘you might get hit by an asteroid while walking in the park but this is rare.’ Mind you, although the experiment we talked about is impossible and morally reprehensible, scientists around the world have been trying very hard to gather data about the risk of HIV transmission via oral sex. They did this through complex questionnaires and very clever statistical analysis. But just like every experiment involving people, there are just too many confounders. E.g. people forget or miss out details of sexual activity, people rarely have oral sex alone, the HIV positive partner may already be on antiretroviral treatment which itself reduces transmission risk anyway etc etc So at the end of the day, these scientific studies are still not able to make the statement ‘HIV cannot be transmitted via oral sex’. Again they come to the same conclusion which is ‘There is a risk of HIV transmission via oral sex but this risk is low to miniscule’. This also means you are never going to come across a doctor who would advise you NOT to have a HIV test because your exposure was ‘only oral sex’. So if you are still worried about having caught HIV via oral sex please remember this one very important fact: YOUR RISK IS EXTREMELY LOW. And yes, this is regardless of the fact that you think you might have a small cut, small scratch, infected hair gland, mouth ulcer, bleeding gums etc etc But LOW risk does not mean NO risk. You still need to get yourself tested

In Conclusion

  • Getting HIV from Oral Sex is possible but extremely rare.
  • The type of oral sex with the highest risk if receptive fellatio.
  • Ejaculation, Gum Disease, Poor Dental Hygiene, Ulcers in the mouth and the presence of blood can increase the risk.
Depiction of fellatio on Attic red-figure kylix, c. 510 BC

Depiction of fellatio on Attic red-figure kylix, c. 510 BC

Also remember that aside from HIV, Oral Sex can transmit a variety of other STDs including:

What should you do now?

If you had a high risk exposure less than 72 hours ago, please see Our Doctors at Our Clinics for a discussion on PEP.

Click here for details on HIV PEP Treatment at Our Clinics

If not, get a HIV test just to be safe.

Click here for HIV Testing FAQ

You should also screen for other STDs that you can get fro Oral Sex.

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advise


Need more advice?

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About Dr. Tan
Dr. Tan graduated from the National University of Singapore in 2001. His residency was in the two largest public hospitals in Singapore; Tan Tock Seng Hospital and Singapore General Hospital.

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832 Comments

  1. Dear Dr ,
    I need ur help as I did protected sex 7 months ago for 2,3mins. Before that she sucked my dick for around 1 mins and then I fingered her. I might put comdom with that hand and did sex. Now I m so much stress as why I put my self on hizard. I m on the edge of suicide as I m too much stress from the last 7 months. Recently I m feeling pain in my throats and dry throat at morning. Plz help me wt to do as I dont have courge to go for test.

    • I think the answer is obvious don’t you? You just have to pick up the courage and go for a test. The alternative is to live in fear for the rest of your life. I can say that your risk of getting HIV from your exposure is not high. However, you still need to test to be sure. Also, please get tested for all other STDs. Your risk of STDs is not low.

  2. Dear Dr, I had a kissing and fingering exposure at massage paloure. No sexual activity. I have hangnails problem. But at that time my cracked cuticle was nor bleeding nor having any pain. After 4days of this incident I m having sore throat with feverish feeling and temperature is also 99 degree F for once. Do I have to worry about this. Pl help. Regards.

  3. 1. Unprotected blow job 5 mins from csw
    2. French kissing 5 mins
    3. Sucking nipples 2 mins
    4. Hand job
    5. No vaginal or anal sex
    6. Risk of HIV

  4. Asientic

    I’m a male. I have sex with a prostitute with beast milk. I drink her milk every time. Am I having any risk?

  5. Im 34 m, married. This is the first time in my life I have made a mistake outside my marriage. I had all my medical check done in my office in KL August end, my HIV and VDRL is negative.
    I had unprotected oral sex (BJ) from a CSW in Kuala lumpur 7 days back. She initially took me into a room , washed me up with water and herself separately and gave me a clean towel to dry. I washed my mouth with water and she did the same. I was made to lie on the bed and she did some massage, i just kissed her on cheeks and neck and sucked her nipples slowly for 2 mins (No secretions came out). Apart from this I did not have sexual intercourse with her either vaginal or anal. Then she gave me a blowjob unprotected for 5 mins. I had french kissed her for 5 mins after the blow job. For briefly 30 seconds, I touched her clitoris with my right middle finger (Without cuts) and did not insert my finger in her vagina. Later she gave me a hand job and I ejaculated on my lower belly, later wiped it with a clean cloth. I wore my under vest and came back. I have not cleaned my penis with water after that. Can I get HIV from Oral blow job? I have not seen or smell of any blood in her mouth or vaginal fluid near me as the vagina was far away from my body.

    Post this episode I have met following Doctors

    1. Doctor in Brickfields (Saturday) provided me Antibiotic injection and 2 tabs (Doxicycline and Flagyl) for 5 days and said dont worry, you are getting anxious , do a test only for your satisfaction. Its very low to get HIV by this way.

    2. Another Doctor in Brickfields (Sunday) again told me the same thing, if you want to get tested, do it after 6 weeks to relieve your anxiety. The transmission is low this way.

    3. I visited an other STD specialist in Bangsar on Wednesday, he told me that if you had come to me within 72 hours, I had given you an anti viral pill. He examined my penis and took a urethral swab and said it was normal. He suggested me to get HIV tested after 4 weeks. He too said it is very very very low by this way.

    4. I had counselling from 2 people including Mr.Martin and said that it was negligible risk.

    Please clarify if I may get HIV? I am very much annoyed and not sleeping.

    If the CSW is HIV positive and she sucks my cock for 5 minutes, does the HIV transmit? I do not have cuts on my penis (Uncircumcised) . But I have not observed any blood in her mouth?? If it were to be, what could be the chances?

    I have french kissed the girl for 2 mins after her blow job? Will this transmit?

    I have not cleaned my penis after I wiped off all semen on my belly? Will this transmit?

    Please tell me with your experience , any case like me with unprotected BJ leading to HIV?

    I can also do the RNA HIV PCR testing if required?

    Please tell me if I need HIV testing in this regard???

    Thanks.

    • I agree with everyone you have spoken to. The risk of HIV from oral sex is negligible.

      • Thanks Dr.Tan

        Few more queries.

        French kissing the girl after she gave me the blow job ? Does this cause HIV?

        I have an uncircumcised penis, when she sucked on it, is there a chance for the HIV virus to run through my pee hole. My penis does not have any cracks/sores ?

        • I have done my tests for STI 10 days later , all have come negative. My HIV 1 & 2 were done by 4th gen elisa after 10 days are negative. A senior HIV specialist in KL did this to me. He says I am not at all at risk, forget the episode and move along. Should I do a RNA PCR to confirm? I m really fearing that this negative test should not turn positive later on? Please help.

  6. Dear Dr, I had protected sex encounter at massege paloure. When the girl was about to sit on my erected penis I ejaculated due to anxiety and stress. It happened as soon as she tried to put penis inside. Other activity was breast sucking in which I tasted some liquid kind of thing thing which I spited it out. Some kissing of few seconds.
    What is my risk?

    Please help.

    Regards

    • Your risk is negligible. If you really are concerned, see a doctor.

      • Thanks Dr for the reply.I have few more queries. It will be great help if you address them.

        1. After ejaculation girl did put my semi erected Penis inside her for 2-6 seconds after that I told her to move away. Is it something I should worry about?
        2. Do you advise me to go for a test or pep,as I have more than 48hrs to start it.

        Regards

        • Also I would like to add that the condom was of lateX rubber. And it was intact. No leakage, slippage and breakage.

          Regards

        • Your risk of getting HIV is very low. I suggest you see a doctor if you are so concerned. We cannot give medical advice over the internet.

          • Dear Dr, I have done hiv CMIA duo test after 47 days, came negative. Test was done on Abbott Architect machine.

            Request your view on this.

            Regards

          • I do not think you have HIV.
            If you are concerned, get tested again in 3 months.

  7. Hi doctor,

    I m a male and i gave 2 prstitutes oral sex for a couple of minutes…. Now im worried about hiv… What should i do? I need to test ? Can i have sex eith mu girlfriend?

    • In my opinion they risk of getting HIV from oral sex if negligible. However the risk of getting other STDs is significant. Please see your doctor to get proper medical advice on the need for testing.

  8. Tailong

    Dear Dr I went to the massage paloure. Did few activities such as closed mouth kiss, kiss on vigina lip, the girl sat on my penis and rubbed it no penitration. What is my risk? Pl address my concerns.

  9. stalin1812

    Hello doctor,

    I was tested Elisa 4th generation test at the month of November 2015, the result value is 0.169 and my partner status is non reactive. Again me and my partner was tested Elisa mode at two weeks before. Both results are negative [My eclia test value is 0.252 and my partner non reactive (Elisa mode)]. Yesterday we have unprotected vaginal and oral sex for two times. today i have mild throat pain and cold.If it symptoms of hiv. I am so worried.Whether it is possible hiv infection between two negative partner. kindly answer me

    • stalin1812

      wheather Elisa Ab mode test for hiv is 3rd genreration or 4th generation test ???doctor.. I am from india.
      what is the accurate window period for Elisa Ab mode test for hiv?

  10. Guy123Guy

    Hi Doc,
    Couple of weeks back I had protected oral sex(condom protected oral sex) with a female escort also, I did perform fingering inside her vagina and I didn’t had any cut or sore. I took my finger out before she cum. I am worried about HIV with this exposure and would like to know if I need to test. ( I did this thing twice with her, everytime with new condom)

    • Oral sex (especially protected oral sex) and fingering both do not carry any risk of HIV infection. It is however my view that all sexually active adults should get regular HIV tests regardless of their risk. Also, you can get other STDs from this.

  11. Dr i would like to knw is the vaginal fluids will stay on the outer labia or inner labia? If without masturbate or fingering.

  12. tensesid

    0I m 50 yr and went to one beauty parlor girl 49 days before and while massaging she took my penis in her mouth for one second. Immediately I removed my penis and told put condom and I received blowjob from her for 2-3 minutes, but my dick was not erec, so I stopped.While sucking I feel her saliva coming down towards the base of my penis where I did shaved my pubic hair before 3 hrs and their might be some minor superficial nicks bruishes abrasions leisions. So what are my risk of acquiring hiv
    1.unprotected oral sex of one second. 
    2. I m not sure I saw any blood,but what if she had bleeding gums or sores in her mouth  and her saliva mix with her blood enter to the unprotected area of my genital area where their is minor superficial cuts before 3 hrs while sucking. 

    After 27 days of exposure I got runny nose for few hrs on first day. 

    Second day I was feeling chills all day.

    Third and fourth day mild sore throat and low grade fever coming and going.I was so scared that,I took rest for 2 days with 3 doses of paracetamol and 3 doses of antibiotic fearing ars symptom.

    Again after 39 days I got runny noses and chills on first day and very very mild sore throat(I dont feel anything otherthan two to three times like clearing sensations) and sometimes low grade fever for half hourto one hour especially in toe and now it is 9th day and Iam not taking any medicine.

     I m very depressed and very fear. 

    I had no other exposure other than this. had not any protected or unprotected vaginal or anal sex with anyone other than my wife since 20 yrs. Should I be tested or no test is required and I ignore this flu like symptoms as not related to hiv and move on.plz help me I m very anxious.
    Whenever I fear I read your article that one shud b involve in high risk, have high fever 38.5, severe sore throat,rash, ulcer n lymp nodes, which helps me to calm down, but still I fear.

    • You cannot get HIV from protected oral sex. Please click HERE to read our article on getting HIV from oral sex.

      • charmingheart

        But their was one second of unprotected oral.
        Also her saliva if mix with blood goes to the unprotected genital shaving nicks.
        My low grade fever and chills is not going since 20 days.( whenever I chk temeparature it is between ,36-36.8 only)
        Does ars fever can b low grade
        Does ars fever goes on it own or need antibiotic course
        Does low grade fever alone can b ars
        At first only their was mild sore throat for 2 days. Now only low grade fever.
        How long the ars fever stay.
        I did my complete blood check up.but the dr are not able to find the cause of low grade fever.which make me more afraid.
        I m.in.middle east which is conservative and no anonymous testing. Anyone found pisitive will b deported.
        I dont have friend or helpline here for advice.
        Drplz help me and give information.
        I m very anxioous and very panicky.

  13. Dr tan cn i get infect if just touch the surface of vaginal(hairy part).

    • You mean with HIV? No you cannot get HIV just by touching the genitals.

      • cheung

        dr tan,

        Dr tan thks for your reply but i was very scare as the next day after this expose.

        • Cheung

          Dr tan, sorry i am want to ask if i got dry crack on my finger or some visible scratch then i touch the vaginal outside or the openening. Is tht will be a risk for me? I cnt see any active bleeding.

        • Cheung

          Dr tan, if there was a small paper cut or paper cut is there will become a risk? As i was discover a small paper cut after 2 days from the expose. I was scare. But during tht time i got wash my hand bt i dint see any bleeding cut. Is this stil no risk?

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