Under the updated guidelines, all potential donors will have to take individualised risk assessments – regardless of their gender identity or sexual orientation.

Anyone who has had anal sex with a new sexual partner, or partners, in the past three months will be deferred.

The FDA said this was in a bid “to reduce the likelihood of donations by individuals with new or recent HIV infection who may be in the window period for detection of HIV by nucleic acid testing.”

Those taking HIV prevention drug PrEP would also be rejected as, despite being safe and effective, “their use may delay detection of HIV by currently licensed screening tests for blood donations, which may potentially give false negative results.”

READ MORE: PrEP: 5 questions about the HIV prevention drug answered

“As stated in the guidance, individuals should not stop taking their prescribed medications, including PrEP, or PEP, in order to donate blood,” the agency continued. “The FDA remains committed to evaluating additional data and new technological developments as they become available to inform our donor eligibility recommendations.”

The changes mean that most gay and bisexual men in monogamous relationships will no longer need to abstain from sex to donate blood.

Previously, men who have sex with men would only be allowed to donate blood if they hadn’t had sex with another man for at least three months.

The new policy will bring the US in line with Canada and the UK, which adopted similar approaches when it comes to blood donations.

The changes put an end to “a dark and discriminatory past” when donating blood

Peter Marks, M.D., PhD., director of the FDA’s Center for Biologics Evaluation and Research, said: “The implementation of these recommendations will represent a significant milestone for the agency and the LGBTQI+ community.

“The FDA is committed to working closely with the blood collection industry to help ensure timely implementation of the new recommendations and we will continue to monitor the safety of the blood supply once this individual risk-based approach is in place.”

READ MORE: London’s A&E departments launch opt-out HIV testing for patients having blood tests

GLAAD praised the updated policy for bringing an end to “a dark and discriminatory past rooted in fear and homophobia.”

The organisation did, however, criticise the FDA’s decision to turn away potential donors who take PrEP for potentially creating “unnecessary stigma”.

“The bias embedded into this policy may, in fact, cost lives,” it said in a statement.