A statement on Sunday said this was based on scientific evidence.
“The FDA concluded, as outlined in its decision memorandum, this product may be effective in treating COVID-19. It also agreed that the known and potential benefits of the product outweigh the known and potential risks,” it said
The treatment involves taking blood rich in antibody from recovered COVID-19 patients (convalescent plasma) and giving the same to those infected.
FDA Commissioner, Stephen Hahn, said the therapy had shown 35 percent success rate.
“I am committed to releasing safe and potentially helpful treatments for COVID-19 as quickly as possible in order to save lives. We’re encouraged by the early promising data that we’ve seen about convalescent plasma,” he said.
The official added that the treatment still needed to undergo randomised clinical trials to determine safety and effectiveness.
The trials started in New York and some other states since April but suffered delays due to insufficient volunteers.
The announcement was made 24 hours after President Donald Trump accused the FDA of delaying vaccine development and production.