U=U
Undetectable = Untransmittable means that people living with HIV who are on effective treatment can’t pass the virus on through sex. That’s not a hope. It’s a fact, backed by science.
What does Undetectable mean?
When someone living with HIV takes antiretroviral therapy (ART) medication, the amount of virus in their blood drops. After a few months, it can become so low that it doesn’t show up on standard blood tests. That’s called having an undetectable viral load.
Being undetectable doesn’t mean you’re cured. But it does mean the virus is under control—and it can’t be passed on. So you’re living with HIV and taking your medication as prescribed, you can live a long, healthy life—and you won’t pass HIV on to your sexual partners.
Why U=U matters
- It’s life-changing for people living with HIV.
- It helps stop new HIV transmissions.
- It fights stigma with science.
U=U is more than a medical fact—it’s a message of hope, dignity and empowerment. It helps people feel confident in their relationships, their health, and their future.
Stigma is still a problem
Stigma means judging or treating someone differently because of their HIV status. It can show up as silence, shame, or assumptions—and it stops people from getting tested, starting treatment, or talking openly about their health. But the science is clear: with treatment, people living with HIV can’t pass it on. HIV stigma has no place in London – and the more people understand that Undetectable = Untransmittable, the faster we end stigma.
What you can do
- If you’re living with HIV: take your meds, go to your check-ups, and know that U=U can apply to you.
- If you’re not sure of your status: get tested. It’s quick, free and confidential.
- Whether or not you’re living with HIV: share the message. U=U helps break down fear and stigma.
U=U changes everything
Proud to promote U=U? Get involved and learn more about activism to end HIV stigma by promoting the fact that Undetectable equals Untransmittable.
Frequently Asked Questions
1. Does Undetectable mean someone is cured of HIV?
No – because there’s currently no cure for HIV. But there is very effective medication that allow most people with the virus to live a long and healthy life, and can’t pass the virus on through sex.
2. Is there a difference between being on treatment and being Undetectable?
Yes, because when someone starts treatment, it can take a few weeks or months for the medication to get the levels of HIV to become so low (under 50 copies/ml) that it doesn’t show up on standard blood tests and become undetectable and untransmissible. People living with HIV receive ongoing treatment, blood tests and expert medical care to make sure they stay at Undetectable levels.
4. What is the evidence for U-U?
Researchers confirmed at the 22nd International AIDS Conference in summer 2018 that the chance of any HIV-positive person with an undetectable viral load transmitting the virus to a sexual partner is scientifically equivalent to zero. It was concluded that ‘zero transmissions mean zero risk’.
Undetectable = Untransmissible (U=U) is a major worldwide campaign that promotes awareness of this evidence, and its implications for HIV prevention. Find out more about the science around U=U from:
- the Prevention Access campaign
- from Aidsmap
5. What is TasP?
TasP = Treatment as Prevention
This is a different way of describing Undetectable = Untransmissible. It means that people living with HIV on correct treatment who are virally suppressed can’t pass the virus on. Because of this, HIV treatment for HIV also acts as a method of HIV prevention – which is why we include it as one of the four sure ways of preventing HIV: testing, condoms, PrEP and U=U.