Atanik

The Atonieks were a race that dwelled in the Milky Way, and predated the Goa'uld and the Tok'ra (though possibly post-dating the Ancients). They were a race who developed unique armbands that released a virus into the wearer, augmenting their natural abilities. However, their immune systems eventually adapted to the virus and they lost their abilities. The Atonieks never found a way around the problem, and their society eventually died out.