With the nation’s blood supply at critical lows—made even worse because of widespread flu outbreaks—the last thing you’d expect at a blood drive is a velvet rope. But that’s what San Francisco Supervisor Mark Leno faced when he offered to donate blood at City Hall last year. It didn’t matter that Leno says he practices safer sex and has repeatedly tested HIV negative. Before he had a chance to roll up his sleeves, he was told, Gay men: Keep out.

But this was no surprise. Since 1985, the Food and Drug Administration (FDA) has required blood centers to reject any male donor who admits to having had sex with another man since 1977. So when news reports called for emergency donations to combat the shortage, Leno spearheaded a drive of his own. He rallied a group of HIV negative gay men to give blood at a local center, where they were turned away before a phalanx of reporters and TV cameras.

“Blood centers shouldn’t be asking with whom a person is having sex,” he said, “but how. This is not only discriminatory, but foolish. It perpetuates the myth that there is something dangerous about gay blood.”

The FDA’s ban has come under fire in recent months, with protests springing up at college campuses and clinics.  Critics argue that the ban is a leftover from the epidemic’s infancy, before an HIV test was even available. (Gay men weren’t the only ones being turned away then—see “Proud of Our Blood.”) “The policy has more to do with public hysteria—and gay men being a political football—than actual risk,” said Jennifer Pittman of the Gay and Lesbian Medical Association (GLMA).

With major strides in testing, many health experts also wonder whether it’s time for a change. Louis Katz, MD, vice chair of science at the America’s Blood Centers, which handle half of the nation’s blood supply, agrees that revisions may be long overdue. “What was reasonable in 1985 may not be today,” he said. “A lot of us think it is not.” But all blood centers, including the Red Cross, must follow FDA rules or risk losing their licenses.

Blood banks can detect HIV just three weeks after a donor is infected, and newer technology may be able to close that window even further. As a result, the U.S. blood supply is safer today than ever, with only one in every 676,000 units of blood infected with HIV. That’s fewer than 20 cases a year that slip through both the questionnaire and testing process.

But even with the best screening, the FDA is concerned that no technology can overcome human error. While ending the ban could add as many as 112,000 donations each year, the FDA estimates that an additional 1,000 to 2,000 HIV positive units could be missed by the questionnaire process. “The benefit you’d get would be a less than 1 percent increase” in the 11 million donations collected each year, Andrew Dayton, MD, told an FDA blood panel in 1997.

Any change, however, will likely be based as much on politics as scientific evidence. And any recommendation by the FDA to relax the ban has to face a Republican-controlled Congress and a public whose fears about HIV-tainted transfusions remain high. “It’s an extraordinarily difficult issue,” Katz said. “If your mother is getting transfused, how safe is safe enough?”

The FDA has been quietly holding public meetings since 1997 to weigh alternatives, including trimming the exclusion period for gay sex from the current 23 years to one or five years. But no one is holding their breath. “There was a rumbling, but nothing happened,” said Darren Carter, MD, GLMA’s policy chair. When POZ asked whether the FDA was planning any future discussion, an FDA spokesperson said only, “We continue to look at this issue.”

But with hospitals nationwide postponing surgeries because of the blood shortage, the FDA may not have the luxury of holding workshops indefinitely. “By my estimates, if one out of every six HIV negative gay men in San Francisco donated blood,” Leno said, “we would not only end the blood shortage here, we would create a surplus.”