The amount of HIV (human immunodeficiency virus) in the blood of a person who is HIV-positive is measured by how many HIV particles are present in a milliliter of blood. This measurement is referred to as the viral load.

Antiretroviral medications, the most common treatment for HIV, help reduce the viral load. The medication must be taken as prescribed every day for it to be most effective in treating the virus and decreasing the chances of transmission.

Sometimes, HIV medications work so well that regular lab testing doesn’t even detect the presence of HIV.

If a person previously diagnosed with HIV has an undetectable amount of HIV in their system following treatment, can they still give HIV to someone else? To better understand the nuances of this important discussion, read on.

According to the CDC, if you take your HIV medication regularly and reach the point where your viral load is undetectable, you have “effectively no risk” of transmitting the virus to an HIV-negative partner through sex.

Having an undetectable viral load also helps prevent transmission to others through sharing needles, syringes, or other injection equipment — though it doesn’t eliminate it entirely.

If you’re dating someone who has an undetectable viral load, you’re not going to test positive for HIV just by having sex. That said, regular testing for HIV, especially if you have multiple sexual partners, is important.

Both the National Institute of Allergy and Infectious Disease and the CDC promote HIV treatment as prevention. Undetectable = Untransmittable or “U=U” is the guiding principle.

If you have HIV and take your HIV medication every day as prescribed, not only are you taking the proper steps to treat the virus, but you’re also helping prevent its spread.

Lowering the amount of the virus in the blood is good for your health, and it’s a step toward keeping your sexual partners healthy too.

Once you get to the point where your viral load is undetectable, it’s important to keep it undetectable. This requires taking your medications regularly as prescribed.

Although most people who have HIV successfully get an undetectable load about 6 months after starting medications intended to reduce the load, not everyone can get an undetectable viral load. In this case, other treatments can help prevent transmission.

Prevention measures include:

  • PrEP. This medication, which stands for pre-exposure prophylaxis works to prevent HIV in people at risk.
  • Condoms. When used correctly and each and every time during sex, condoms are very effective in preventing HIV and other STIs.
  • Little or no sex risk. This refers to both sexual partners and types of sexual activity. Oral sex carries little to no risk of transmitting HIV.
  • STI testing. Regular screening for HIV and other STIs is a preventative measure that can also put your mind at ease.
  • PEP. This medication stands for post-exposure prophylaxis. If taken within 72 hours of a possible exposure, it may prevent HIV.

Sharing needles or syringes is never OK. If you or someone you know struggles with drug addiction, there are resources that can help, including syringe services programs (SSPs). SSPs are community-based prevention programs that provide new needles and syringes along with a safe way to dispose of used ones.

Other resources include:

For people living with HIV, the stigma can often be as hard as managing the physical effects themselves. While we’ve come a long way since the virus was first discovered in the U.S. in 1981, HIV and AIDS, the late stage of HIV infection, still carry a stigma. For people living with HIV, the stigma may have a profound effect on overall health and well-being.

HIV’s transmission through sex and drug use is one of the biggest reasons the stigma persists today, in spite of major medical advancements. HIV education programs, visibility of HIV-positive celebs like Jonathan Van Ness and Billy Porter, and increased awareness of how the virus can and can’t be transmitted are helping destigmatize it, but more work needs to be done.

For example, an HIV-positive person spitting on a person who doesn’t have HIV is considered an illegal act in a number of states, even though spit isn’t a bodily fluid that’s a transmission risk.

If you have HIV and are struggling to get support from friends and family, consider sharing information from the CDC on U=U and other medical literature to increase awareness and understanding. While studies show increasing acceptance and comprehension of U=U among queer men, the general population continues to misunderstand HIV transmission.

You don’t have to be an HIV advocate or leader in the movement to educate people on transmission, but the more you know, the easier it’ll be to participate intelligently when conversations on HIV and its transmission come up.

Since these may often be hard conversations, it’s important to take time for yourself too. Try meditation or journaling, and don’t forget about the value of self-care.

Building a sense of community with other HIV-positive people can help you build new friendships with people who understand and also lead to a developed sense of pride and identity.

If an HIV-positive person has an undetectable viral load, they have effectively no risk of transmitting HIV to an HIV-negative person through sex. It is still possible through other means like direct blood-to-blood contact when sharing syringes, though the risk is reduced. Most people with HIV can reach an undetectable viral load by taking their HIV meds exactly as prescribed.