Following the Food and Drug Administration's recent reversal on its lifetime ban of gay men as blood donors, protesters gathered outside the agency's field office in Philadelphia to object to rules they say are still discriminatory.

For 31 years, the United States has barred men who have had sex with men after 1977 from donating blood, primarily out of fear of spreading HIV. Last week, the FDA announced it would seek new guidelines in 2015, allowing those men to donate as long as they have not been sexually active with another man for a year.

While acknowledging that's an improvement over the blanket ban, the half dozen activists said the new policy remains unfair to homosexual men. It would, for example, disqualify monogamous gay couples, yet do nothing to protect blood supplies from heterosexuals who engage in risky sexual behaviors.

"I'm HIV-negative, I'm O-negative, and I would love to give blood," said Ed Coffin, who organized the protest. "The only way I can do that right now is by lying on the questionnaire."

Another protester, Keira Devine of South Jersey, noted that blood donations are already tested for a battery of diseases before being given to patients.

"I think it's time that we evolve and get over our homophobic feelings," she said.

A better system, Coffin said, would allow each potential donor — homosexual or heterosexual —  to be evaluated for risk on a case-by-case basis.

In a statement, the FDA said it had considered individual self-assessments, but did not find them reliable.

"Assessment of high-risk sexual behaviors would be highly burdensome on blood donation establishments and potentially offensive to donors," the agency wrote.

The FDA also said there is not yet enough evidence to reduce the waiting period to less than one year.