It's the little yellow pill that scientists say may one day help prevent some chronic diseases and help you live well a longer life. That claim may be hard to swallow, but on Thursday night, ABC's "Primetime Live" co-anchor John Quinones takes the promising antioxidant therapy called Protandim.

"I have become a guinea pig for ABC News and ëPrimetime,'" Quinones said. "It's not a drug supplement. It's called Protandim, and it's a combination of five exotic plants that have been around for centuries."

So have these scientists discovered the fountain of youth? "I wouldn't put it that way," the developer states. "But we may have discovered something that will tell us a lot more about how we age, what happens biochemically, and maybe how we can slow it down."

How did it work for John? After taking Protandim for two weeks, Quinones told "Extra," "I am sleeping a lot better. I feel a lot better and am also energized when I wake up."

So is it health industry hype or a medical miracle? Learn more when "Primetime" puts Protandim to the test, Thursday night.