It's a situation any gay man who has ever tried to donate blood knows well.

"Not only can I not give blood but I have to explain to this stranger who I don't know that I can't give blood. Its mortifying," said Kristofer Fegenbush. He is the Chief Operating Officer of the Pride Center in Wilton Manors.

It was his father who taught him the importance of giving blood as a child.

"I would go and sit and eat the cookie and drink juice and sit with my father and gave blood," he says.

As an adult, he no longer can because of a three decades old Food and Drug Administration policy. It was put into place during the AIDS epidemic, and it bans gay men from donating for a lifetime.

Before extending your arm and wincing, you have to answer the question: "From 1977 to the present--have you had sexual contact with another male--even once? If you can answer yes, you will be deffered for a lifetime.

"It's shaming, it's discriminatory, it's stigmatizing, it's outdated," Fegenbush said.

Recently Campbell, California's openly gay mayor made headlines when he was deferred from donating. He calls the practice discriminatory.

"If you are heterosexual and engage in promiscuous activity you can still donate blood," Mayor Evan Low said.

He and lawmakers like Massachussets Senator Elizabeth Warren are pushing for a change. Earlier this month she and 84 members of Congress sent a bipartisan letter to the Secretary of the Department of Health and Human Services, urging a re-evalution of blood donation policies.

"For me, this has been a basic issue of fairness and science--blood donation policies should be grounded in science, not ugly and inaccurate stereotypes," she said on her website.

The FDA says the ban is based on scientific evidence showing higher rates of transmissible diseases among men who have sex with men, compared to individuals who only have sex with members of the opposite gender. It further says in a statement, the practice is not meant to target one group over another.

"The FDA defers other donors when they present similarly high risks for exposure to transfusion transmissible infections, whether through behavior, medical conditions, or geographical exposures, " the FDA said in a statement to MSNBC.

Gay rights supporters though believe the FDA policy should be based on behavior and not orientation.

"We could look at an individuals individual risk of people. A lifetime ban based on having a sexual relationship with a man is just not good science," said Fegenbush.