Condoms alone aren’t cutting it, the World Health Organization declared today, urging all men who have sex with men—regardless of HIV status—to begin using antiretroviral drugs as a means of protection against the disease.

Worldwide, a man's risk of HIV infection is 19 times greater if he has sex with other men than if he doesn't. Taken regularly, the recommended pre-exposure prophylaxis, or PrEP—a single daily pill containing two separate medications—is up to 92 percent effective in protecting its users from HIV. In an update to its HIV prevention guidelines, the WHO estimated that the widespread use of PrEP among gay and bisexual men could prevent as many as one million new HIV infections over the next decade.

It’s a number worth celebrating, in theory, but how attainable is it? In the same guidelines released earlier today, the agency also noted that its recommendation may be easier said than fulfilled:

“Implementation may prove challenging, however, where access to services and provision of alternative prevention tools are limited or lacking. Issues of criminalization, stigma and discrimination, and violence should be considered during implementation, especially where same-sex behavior is illegal.”

And as the BBC reported in February, homosexuality is a capital crime in five countries and punishable with imprisonment in 70 more, leaving a sizeable chunk of the world’s high-risk population unlikely or unable to follow the WHO’s wishes.