Undetectable = Untransmittable (U=U)

Testing for, treatment of, and living with HIV (Human Immunodeficiency Virus) has changed radically over the last few decades. With developments in HIV medication (anti-retroviral treatment or ART) the majority of people living with HIV can achieve an undetectable viral load. This does not mean that the HIV is gone, it means that copies of the HIV virus cannot be detected using particular tests.


The results are given per millilitre of blood and, if the results are undetectable, this means that there are fewer than 50, 40 or sometimes 20, copies per ml. 95% of people in the UK become undetectable after 6 months of treatment, and medical guidelines suggest that someone who receives a positive diagnosis (i.e. tests positive for HIV) should be placed on treatment as soon as possible – usually between 20 to 30 days of testing positive but often within a few days.


Study after study has shown that someone with an undetectable viral load is unable to pass the virus on to someone else. This is sometimes also called Treatment as Prevention or TasP. This is a fantastic development because it means that if someone living with HIV (is HIV positive) has unprotected sex with someone who is HIV negative (not living with HIV) they can't pass on the virus. However, being undetectable does not protect a person from other sexually transmitted infections (STIs) so regular sexual health screening are still recommended if the person is sexually active, and being undetectable does not prevent pregnancy.


The term Undetectable = Untransmittable (U=U) is a really powerful way that we can help reduce the fear that many people still have of HIV and the stigma this creates for people living with HIV. Nevertheless, there remains some people who are unable to achieve an undetectable viral load for various reasons (personal, medical, psychological or physical), and it is important that these HIV positive people are not treated any differently both socially and in accessing services.