The US Food and Drug Administration has approved Truvada for use in HIV prevention.
The drug has been approved for Pre-Exposure Prophylaxis or PrEP, which is the use of antiretroviral drugs to decrease the likelihood of HIV infection in people with a high risk of contracting it.
However, the FDA emphasised the need for other prevention methods, such as safe sex practices, risk reduction counselling and regular HIV testing.
FDA commissioner Margaret A Hamburg said: “Today’s approval marks an important milestone in our fight against HIV.
“Every year, about 50,000 US adults and adolescents are diagnosed with HIV infection, despite the availability of prevention methods and strategies to educate, test, and care for people living with the disease.
“New treatments as well as prevention methods are needed to fight the HIV epidemic in this country.”
This autumn, a UK clinical trial will examine the efficacy of a daily PrEP pill to prevent HIV.
The trial, called PROUD, (Pre-exposure Option for Preventing HIV in the UK), is a collaboration between the Medical Research Council and the Health Protection Agency.