Condoms are a highly effective method for preventing the transmission of HIV during sex. However, many people don’t use them or don’t use them consistently. Condoms may also break during sex.

If you think you may have been exposed to HIV through sex without a condom, or due to a broken condom, make an appointment with a healthcare professional as soon as possible.

If you see a doctor within 72 hours, you may be eligible to start a medication to reduce your risk of contracting HIV. You can also set up a future appointment to be tested for HIV and other sexually transmitted infections (STIs).

Read on to learn more about:

  • preventive medications
  • how soon after condomless sex it makes sense to be tested for HIV
  • the main types of HIV tests
  • the risk factors of different forms of condomless sex

Keep in mind, if you believe you’ve been exposed to HIV, it’s important to see a healthcare professional as soon as possible.

There’s no HIV test that can accurately detect HIV in the body immediately after exposure. There’s a time frame known as the “window period” before you can be tested for HIV and receive accurate results.

Regardless of the type of test you take after a potential HIV exposure, you should get tested again after the window period has passed to be certain.

People at higher risk of contracting HIV should get regularly tested as often as every 3 months.

How soon can HIV be detected by a blood test?

The window period refers to the time between when a person is first exposed to HIV and when it will show up on different types of HIV tests.

The window period can last anywhere from 10 days to 3 months, depending on your body’s immune response and the type of test that you’re taking.

During the window period, a person may test HIV-negative even though they’ve contracted HIV.

A person can still transmit HIV to others during this period. In fact, transmission may even be more likely because there are higher levels of the virus in a person’s body during the window period.

Here is a quick breakdown of different types of HIV tests and the window period for each.

Rapid antibody tests

This type of test measures antibodies to HIV. The body can take up to 3 months to produce these antibodies.

Most people will have enough antibodies to test positive within 3 to 12 weeks after contracting HIV. At 12 weeks, or 3 months, 97 percent of people have enough antibodies for an accurate test result.

If someone takes this test 4 weeks after exposure, a negative result may be accurate, but it’s best to test again after 3 months to be sure.

Combination tests

These tests are sometimes referred to as rapid antibody/antigen tests, or fourth generation tests. A healthcare professional can order this type of test. It must be conducted at a lab.

This type of test measures both antibodies and levels of the p24 antigen, which can be detected as soon as 2 weeks after exposure.

In general, the majority of people will produce enough antigens and antibodies for these tests to detect HIV at 2 to 6 weeks after exposure.

If you test negative at 2 weeks after you think you may have been exposed, your healthcare professional will likely recommend another test in 1 to 2 weeks, as this test can be negative in the very early stage of contracting an HIV infection.

Nucleic acid tests

A nucleic acid test (NAT) can measure the amount of the virus in a blood sample and provide either a positive/negative result or a viral load count.

These tests are more expensive than other forms of HIV testing, so a doctor will only order one if they think there’s a high chance that a person was exposed to HIV or if screening test results were indeterminate.

There is typically enough viral material present for a positive result 10 to 33 days after possible exposure to HIV.

Home testing kits

Home testing kits such as OraQuick are antibody tests that you can complete at home using a sample of oral fluid. According to the manufacturer, the window period for OraQuick is 3 months.

How quickly a person is able to see a healthcare professional after exposure to HIV can significantly affect their chances of contracting the virus.

If you believe you’ve been exposed to HIV, or have a high risk of being exposed to HIV, visit a healthcare professional within 72 hours. You may be offered an antiretroviral treatment called post-exposure prophylaxis (PEP), which can reduce your risk of contracting HIV. PEP is typically taken once or twice daily for 28 days.

PEP has little or no effect if taken more than 72 hours after exposure to HIV, according to the Centers for Disease Control and Prevention (CDC). The medication isn’t usually offered unless it can be started within the 72-hour window.

During condomless sex, HIV in the bodily fluids of one person may be transmitted to the body of another person through the mucous membranes of the penis, vagina, and anus. In very rare cases, HIV could potentially be transmitted through a cut or sore in the mouth during oral sex.

Out of all types of condomless sex, HIV can most easily be transmitted during anal sex. This is because the lining of the anus is delicate and prone to damage, which may provide entry points for HIV.

Receptive anal sex, often called bottoming, poses more risk for contracting HIV than insertive anal sex, or topping.

HIV can also be transmitted during vaginal sex without a condom, although the vaginal lining is not as susceptible to rips and tears as the anus.

The risk of acquiring HIV from oral sex without using a condom or dental dam is very low. It would be possible for HIV to be transmitted if the person giving oral sex has mouth sores or bleeding gums, or if the person receiving oral sex has recently contracted HIV.

In addition to HIV, anal, vaginal, or oral sex without a condom or dental dam can also lead to transmission of other STIs.

The most effective way to prevent HIV transmission during sex is to use a condom. Get a condom ready before any sexual contact occurs, since HIV can be transmitted through pre-ejaculate, vaginal fluid, and from the anus.

Lubricants can also help reduce the risk of HIV transmission by helping prevent anal or vaginal tears. The right lubricants also help prevent condoms from breaking.

Only water-based lubricants should be used with condoms. Oil-based lube can weaken latex and sometimes cause condoms to break.

The use of a dental dam, a small plastic or latex sheet that prevents direct contact between the mouth and the vagina or anus during oral sex, is also effective at reducing the risk of HIV transmission.

For people who may have a higher risk of contracting HIV, preventive medication is an option. Pre-exposure prophylaxis (PrEP) medication is a daily antiretroviral treatment.

Everyone at high risk of HIV should begin a PrEP regimen, according to a recommendation from the U.S. Preventive Services Task Force.

Per the recommendation, sexually active people are considered at high risk of HIV if they have one of the following characteristics:

  • in a sexual relationship with someone who is living with HIV
  • inconsistent condom use during sex with a partner whose HIV status is not known and who may be at high risk
  • having a sexually transmitted infection (STI), such as syphilis or gonorrhea within the past 6 months
  • for men, inconsistent condom use during anal sex

Although PrEP does provide a high level of protection against HIV, it’s still best to use condoms as well. PrEP only provides protection against HIV, not against other STIs.

Remember, if you think you may have been exposed to HIV by having sex without a condom, make an appointment to speak with a healthcare professional as soon as possible. They may recommend PEP medication to reduce your risk of contracting HIV.

A healthcare professional can also discuss a good timeline for HIV testing, as well as testing for other STIs.