Can I Transmit HIV If I Have an Undetectable Viral Load?

HIV medicine lowers the amount of virus (viral load) in your body, and taking it as prescribed can make your viral load undetectable.

Sex Partners

If your viral load stays undetectable, you have effectively no risk of transmitting HIV to an HIV-negative partner through sex.

Needle-Sharing Partners

We don't know whether getting and keeping an undetectable viral load prevents HIV transmission through sharing needles or other injection drug equipment. It very likely reduces the risk, but we don't know by how much. Never share needles and other equipment to inject drugs.


If a woman living with HIV can take HIV medicine as prescribed throughout pregnancy, labor, and delivery and if HIV medicine is given to her baby for 4-6 weeks after delivery, the risk of transmission from pregnancy, labor, and delivery can be reduced to 1% or less. We don't know if a woman living with HIV who has her HIV under control can transmit HIV to her baby through breastfeeding. While we do not yet know if or how much being undetectable or virally suppressed prevents some ways that HIV is transmitted, it is reasonable to assume that it provides some risk reduction.

Treatment is a powerful tool for preventing sexual transmission of HIV. But it works only as long as you keep an undetectable viral load.

Consider taking other actions to prevent HIV, like using condoms or pre-exposure prophylaxis (PrEP), if you or your partner wants added peace of mind. Taking these other actions can be useful, especially if you

  • Have trouble regularly taking HIV medicine,
  • Have an increased viral load, or a load of 200 copies/ml of blood or greater,
  • Haven't had a recent test (last 3-4 months) that shows the viral load is undetectable,
  • Missed some doses since the last viral load test, or
  • Have stopped taking HIV medicine in the past and may choose to do so again.

Also use condoms if either partner is concerned about getting or transmitting other STDs.

How Do I Talk to My Partner About Safer Sex?

Whether you have HIV or want to take precautions against getting HIV, here are some conversation starters to help you begin talking about safer sex options with your partners include:

  • I really like you, and like where this is going, but before we go any further, there's something I want to tell you. I'm HIV-positive.
  • Let's start talking about ways to keep each other healthy and safe. When was the last time you were tested for HIV?
  • Did you know that there are medicines that you can take that can further reduce the chance of you getting HIV? Have you heard of PrEP (pre-exposure prophylaxis)? Maybe we should talk to our doctors to see if it's right for us.
  • Can we talk about sex? Safer sex is really important to me.
  • So we haven't really talked about it, but can we agree that when the time comes, we'll use condoms to keep each other safe?
  • I know we just met and we don't know everything about each other, but you should know that practicing safer sex is really important to me. When is the last time you were tested for HIV and other sexually transmitted diseases?

For partners that are both living with HIV:

  • If we're going to have sex, let's get tested for other STDs together before we take that step.
  • Getting an STD could really compromise our health. Let's stay healthy and get tested for STDs regularly.
  • Let's talk about how we can practice safer sex so that we don't increase our chances of getting an STD or a new strain of HIV.

[Note from TheBody: This article was created by the U.S. Centers for Disease Control and Prevention, who last updated it on July 24, 2018. We have cross-posted it with their permission.]