Talk with your sex partner or partners about their sexual history as well as your own sexual history. Find out whether your partner has a history of behaviors that increase his or her risk for HIV.
You may be able to take a combination medicine (tenofovir plus emtricitabine) every day to help prevent infection with HIV. This medicine can lower the risk of getting HIV.9, 10, 11 But the medicine is expensive, and you still need to practice safer sex to keep your risk low.
Alcohol and drugs
If you use alcohol or drugs, be very careful. Being under the influence can make you careless about practicing safer sex.
And never share intravenous (IV) needles, syringes, cookers, cotton, cocaine spoons, or eyedroppers with others if you use drugs.
If you already have HIV
If you are infected with HIV, you can greatly lower the risk of spreading the infection to your sex partner by starting treatment when your immune system is still healthy.
Experts recommend starting treatment as soon as you know you are infected.1
Studies have shown that early treatment greatly lowers the risk of spreading HIV to an uninfected partner.12, 13
Your partner may also be able to take medicine to prevent getting infected.3 This is called pre-exposure prophylaxis (PrEP).
Steps to prevent spreading HIV
If you are HIV-positive (infected with HIV) or have engaged in sex or needle-sharing with someone who could be infected with HIV, take precautions to prevent spreading the infection to others.
Take antiretroviral medicines. Getting treated for HIV can help prevent the spread of HIV to people who are not infected.
Tell your sex partner or partners about your behavior and whether you are HIV-positive.
Follow safer sex practices, such as using condoms.
Do not donate blood, plasma, semen, body organs, or body tissues.
Do not share personal items, such as toothbrushes, razors, or sex toys, that may be contaminated with blood, semen, or vaginal fluids.
If you are pregnant
The risk of a woman spreading HIV to her baby can be greatly reduced if she:
Is on medicine that reduces the amount of virus in her blood to undetectable levels during pregnancy.