Can You Spread HIV With an Undetectable Viral Load?

Medically Reviewed by Jonathan E. Kaplan, MD on June 10, 2022
3 min read

When you have HIV, your viral load is the amount of virus in your blood and body fluids. It’s usually highest when you first find out that you have it.

HIV medicine called antiretroviral therapy (ART) slows or stops the virus from growing. When you take it every day as prescribed, your viral load should come down to a very low level. That can keep you healthy for years.

Eventually, you want to have an undetectable viral load -- one so low that a lab test can’t find it. When you have an undetectable viral load, you can’t spread the virus to your sexual partner(s).

Even when you reach that point, you must remember that the virus is still in your body. To keep it at bay, take your medicine every day, just as your doctor prescribes. If you skip doses or stop treatment, your viral load can go up quickly. The chance that you can transmit the virus to your partners also goes way up.

Tell your doctor if you have trouble sticking to your treatment.

Talk to your partners, too about prevention of HIV (if HIV-uninfected) as well as non-HIV STD issues. Discuss other kinds of protection, like condoms, safer sex, or pre-exposure prophylaxis (PrEP). This daily pill can lower the chance of infection in people who don’t have HIV by up to 99%.

An undetectable viral load isn't a free pass. There are still important details that you must keep in mind.

HIV medicine and pregnancy.If you want to get pregnant, you'll need appropriate medical supervision and continue to take your meds to maintain viral suppression. This can generally be done safely while you’re pregnant and during delivery and can help your baby stay healthy. Your baby also needs treatment for a few weeks after birth. These measures help ensure you won’t pass the virus to your newborn.

HIV can spread through breast milk. There’s probably less chance of this if you have an undetectable viral load, but it's not for sure. Talk to your doctor about what’s best for you and your baby.

Even if you’re on ART and your viral load is undetectable, you can still get other STDs. This includes gonorrhea, chlamydia, syphilis, herpes simplex virus ​​​​​​​(HSV),  and hepatitis B and C. PrEP doesn’t protect against other STDs, either.

To lower your chances:

  • Use a new condom every time you have sex. Be sure you know the right way to use it and leave it on the whole time.
  • Limit the number of partners you have sex with.
  • Don’t drink or use drugs before or during sex.
  • Get tested. STDs don’t always cause symptoms. The only way to know for sure if you have an STD is to get tested. Talk to your doctor about the tests you want and need. Your partners should do the same thing.
  • Have an honest discussion with your partners about the best ways to stay safe and healthy.

HIV can spread when you share needles to inject drugs. Your odds of infection may be less if you:

  • Use clean equipment every time you inject.
  • Don't share needles.
  • Take HIV medicine.
  • Maintain an undetectable viral load.