Anti-HIV drug Truvada backed for all high-risk adults
Women and straight men at high risk of contracting HIV should also have access to a pill that can help prevent the virus, says US health officials.
The government previously advised doctors to give the pill Truvada to high-risk gay and bisexual men only.
But the Centers for Disease Control and Prevention say straight people make up over 25% of new HIV cases each year.
Truvada has been used to treat Aids patients since 2004, but was approved last month as a preventive measure.
"That's not a portion of the epidemic we want to ignore," Dr Dawn Smith, CDC expert and main author of the new guidance, said of the decision to expand the advice for Truvada.
The medication has not been suggested for use by all sexually active people. Even among couples where one person is infected with HIV, using a condom is adequate protection, experts say.
But Dr Smith said the pill might be used, for example, by couples trying to have a baby.
When used as a preventive measure, the Truvada pill is taken once a day and can cost between $6,000 (£3,840) and $12,000 per year.
But some private insurance companies and Medicaid programmes have covered it, Dr Smith said.
Gilead Sciences, the company that makes the drug, has said it is difficult to know how many people are using the medicine as a HIV-prevention measure.