What is the risk of getting HIV?

One of the most common questions I am asked is

“How big is the risk of getting HIV from…”

with … being a particular sexual act.

Today I want to explain how doctors evaluate risk when it comes to potential exposures to HIV.

To acquire HIV, you need a bodily fluid that contains HIV to enter your body. This can be via the blood stream or contact with a mucous membrane such as the lining of the anus or vagina.
Body fluids that contain HIV in high enough amounts to infect include blood, semen, vaginal secretions, anal mucosa secretions and breast milk.

Saliva is not a risk for transmitting HIV. It contains enzymes that break the virus down, and there’s too little virus in it to infect anyone.

What Is The Risk Of Particular Acts?

Exposure	Risk of transmission of HIV*
Receptive Anal Sex With Ejaculation	1/70
Receptive Anal Sex No Ejaculation	1/155
Shared Injecting Equipment	1/125
Insertive Anal Sex With Foreskin	1/160
Insertive Anal Sex Circumcised	1/900
Receptive Vaginal Sex	1/1250
Insertive Vaginal Sex	1/2500
Oral Sex	Extremely low
Needle Stick Injury	1/440
Mucous Membrane or Broken Skin Contact	<1/1000

* Risk per act where no condom was used, and assuming your partner has HIV. These are the Australian guideline figures (ASHM 2025). ¹ The four anal sex rows come from a Sydney study that followed 1,427 gay men in the early 2000s; ² the rest are ASHM’s compiled estimates from other sources.

Two things the table doesn’t tell you. It isn’t broken down by your partner’s viral load: the numbers come from a real-world mix of partners, some on treatment and some not, averaged together. And ASHM’s own caveat is that these estimates “do not adequately estimate an individual’s risk after a single exposure”. They describe populations, not your Saturday night.

A person living with HIV who is on treatment and has kept an undetectable viral load for at least six months cannot pass HIV on to a sexual partner. That’s U=U, and it’s settled. If that’s your partner, the sexual risks in the table above don’t apply to you. (U=U is about sex. It isn’t the evidence base for sharing injecting equipment, needlestick, or broken-skin contact, so those non-sexual rows still stand.)

Condoms, used properly and every time, cut the risk dramatically. They aren’t a force field (they can slip or break), but correct use is one of the most effective things you can do.

If you want another layer on top, start with how to start PrEP in 2026.

If this already happened

If you’re reading this because of something that happened recently, this is the time-critical part.

PEP is a month of tablets that can stop HIV establishing itself after an exposure. It has to start within 72 hours, and the sooner the better. That’s the outer limit, not the target.

Where to get it: a sexual health clinic, an emergency department, or some GPs. In Australia you can ring 1800 PEP NOW (1800 737 669) to find your nearest service. Don’t wait for a test result to decide, and don’t wait until Monday.

If it’s been longer than 72 hours, PEP has missed its window. Book a test instead. An HIV test can’t see an infection picked up in the last few weeks, so if you’re testing very soon after an exposure you’ll usually need a repeat test later. We can talk you through the timing.

And if you get a fever, sore throat, rash or swollen glands in the weeks after a possible exposure, get seen and say why.

Questions About Specific Sexual Acts.

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Can I Get HIV From Massage?

Massage and rubbing bodies against each other presents no risk of passing on HIV.

HIV is not able to be transmitted through intact skin.

If you have any cuts, sores or open wounds it is best to avoid massage or contact with bodily fluids.

Massage is a fun, safe and therapeutic way to relax. Sometimes a massage has erotic elements such as masturbation or oral sex. Both carry very low HIV risk (see below).

Can I Get HIV From Masturbation?

Masturbation both solo and mutual is not a risk for acquiring HIV.

Even if bodily fluids such as semen or vaginal secretions come into contact with your skin, as long as there are no cuts, sores or open wounds you are safe.

Masturbation is an excellent choice for fun safe sex with yourself, partner or partners.

Can I Get HIV From Oral Sex?

The risk of HIV from oral sex is extremely low, low enough that it doesn’t get a number in the table above. There’s a small theoretical risk if there are breaks in the skin, ulcers, sores or cuts on the genitals or in the mouth.

For the person receiving oral sex on a penis, the risk is negligible.

While HIV can be transmitted in vaginal secretions, the exposure to these is very low for a person giving oral sex on a vagina. Saliva also contains enzymes that kill HIV.

A person giving oral sex to someone with a penis has a negligible risk if there is no ejaculation or precum present. Volumes of precum are usually quite low, and the enzymes in saliva degrade any HIV present.

Ejaculation into the mouth poses a very low risk of HIV, again because saliva degrades the virus and there is little exposed mucosa for it to cross.

If there are any ulcers, cuts, sores in the mouth or recent dental extractions it is best to avoid oral sex with ejaculation.

Use of condoms or dental dams for oral sex essentially eliminates any risk of HIV being passed.

Good dental care is recommended such as daily flossing and brushing of teeth.

Can You Get HIV From Kissing?

Saliva contains proteins and a low salt content that actively reduce its infectiousness.

Even when HIV is detected there is too little to cause infection.

HIV is not transmitted by kissing including deep kissing. Spit cannot transmit HIV.

Resources:

• CDC Guide To HIV Risk & Oral Sex
• Ending HIV - Oral Sex
• AFAO - Risk of HIV & Oral Sex

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This information is general in nature and not a substitute for personalised medical advice. Speak to your doctor about your specific situation.

Dr George Forgan-Smith, GP, practising in Sydney and Melbourne. AHPRA MED0001197864.