Undetectable = Untransmittable (U=U)
When taken as prescribed, HIV medications can decrease the amount of HIV present in blood to be too low to measure. This is called being undetectable.
A person living with HIV who gets and stays undetectable has effectively no risk of transmitting HIV to their sex partners.
This concept is known as Undetectable = Untransmittable (U=U).
How it works
Become undetectable. This can take up to 6 months after starting HIV medication. Your health care provider will perform blood tests and let you know when you’re undetectable.
- Stay undetectable. Get a second undetectable test result at least 6 months after the first. Continue to take your HIV medications daily and visit your health care provider regularly. They will monitor your blood tests to make sure you’re still undetectable.
10 Thing to Know About HIV Suppression
Visit the National Institute of Allergy and Infectious Diseases to learn more about HIV suppression, or being undetectable, and see a video of how it works.
- HIV Treatment as Prevention
U=U only applies to sexual transmission of HIV. See HIV Treatment as Prevention to learn how HIV treatment impacts perinatal (mother-to-child) and injection drug use transmission.
HIV Undetectable = Untransmittable (U = U)
The New York City Health Department page about U=U includes frequently asked questions.
HIV Undetectable = Untransmittable (U = U) — Information for Providers
The New York City Health Department page about U=U information for health care providers.
- Prevention Access Campaign
The Prevention Access Campaign started the international U=U campaign. View the consensus statement, frequently asked questions, list of community partners and more.