Undetectable = Untransmittable (U=U) for You!

What does Undetectable = Untransmittable mean?​

Thank you for visiting! Whether you are positive or negative this information is important for you.

"Undetectable" means that a test cannot detect the amount of virus in a blood sample from a person living with HIV. Someone who is "undetectable" for 6 or more continuous months while on treatment does not transmit the virus.

An undetectable viral load has different measures depending on the test and country. For instance, in the U.S., this means about <40 copies of HIV per milliliter of blood. Studies show that HIV transmission does not occur if viral load is <200 copies/ml. This is also called being “virally suppressed.” Being “undetectable” and “virally suppressed” are often used interchangeably. They both indicate that transmission will not occur.

Undetectable doesn't mean that there's no HIV present in blood. It just means the virus is being controlled. If a person with undetectable HIV stops their medications, the virus will return to being detectable which increases the risk of transmission.

The lingo

These terms are often used when describing this evidence-based HIV prevention method: "undetectable", "TasP" (or "treatment as prevention"), and "U=U" or "undetectable equals untransmittable". Basically, they all mean the same thing ... if a person living with HIV stays undetectable for 6 months or more then they cannot transmit HIV through sex.

Scientific evidence

Three international studies showed no HIV transmissions among mixed-status couples when the partner with HIV was undetectable for 6 months or longer. This included more than 75,000 acts of reported condomless sex among mixed-status heterosexual and gay male couples. The studies were HPTN 052PARTNER and Opposites Attract. To date worldwide there are no verified reports of someone getting HIV from a partner who is undetectable.

I want more information!

For more information on the U=U campaign and the science behind U=U, visit Prevention Access Campaign

For more information for trans and cis women living with HIV, visit the resources on HIVE's Women Living with HIV and Trans Women pages . 

For more information for cis and trans men living with HIV, visit the resources on HIVE's Men Living with HIV and Trans Men pages. 

Visit our U=U for advocates page for more in-depth resources and information. 


In collaboration with Prevention Access Campaign logo