The Food & Drug Administration (FDA) announced Friday it would reexamine its policy that bans gay men from donating blood, the Los Angeles Times reported.

The FDA currently imposes a lifetime ban on men who have had a sexual relationship with another man since 1977 from donating blood. But the agency only excludes people who have engaged in heterosexual sexual activity with a person know to have HIV, the virus that causes AIDS, for one year.

Gay rights groups have said the policy creates an unfair double standard and that it stigmatizes gay men.

The announcement comes after Massachusetts Senator John Kerry, along with 17 Democratic lawmakers, wrote to FDA Commissioner Margaret Hamburg asking the agency to reverse the policy.

The lawmakers argue that the ban specifically singles out gay men and is “scientifically unsound,” in their March 4 letter.

“Prospective donors who have engaged in heterosexual sexual activity with a person known to have HIV are deferred for one year. At the same time, male donors who engaged in protected homosexual sexual activity with a monogamous partner 26 years ago are deferred for life.”

“The ban also does not distinguish between safe and unprotected sexual activity. As a result, healthy blood donors are turned away every day due to an antiquated policy and our blood supply is not necessarily any safer for it,” the letter says.

The FDA initially resisted Kerry's request, saying that the ban “is based on current science and data,” in a statement released to the press on the same day.

Kerry, however, wrote a second letter asking Hamburg to share the agency's scientific data.

“We did not write to the FDA to defend the people's desire to donate blood,” Kerry said. “Please share with us the current science and data referenced in your statement used to continue to justify this policy.”

Allowing gay men to donate blood is opposed by hemophilia patient groups. In the late 1970s and early 1980s about 10,000 hemophiliacs were infected with HIV before the agency implemented the policy.

Technological improvements in screening the nation's blood make the policy unnecessary, the lawmakers argue.

“We live in a very different country than we did in 1983,” the letter says. “Today, the high-risk behaviors associated with HIV contraction are more fully understood and dramatic technological improvements have been made in HIV detection. … As a result [of screening], the blood banking community believes that the lifetime deferral is no longer necessary to protect the integrity of the blood banks.”

The policy will be reexamined by the Department of Health and Human Services' blood safety committee in June, according to the statement.