Classic for more than 20 years! Get time-tested, scientifically researched immune system support with 4Life’s original immune system supplement: 4Life Transfer Factor® Classic. 4Life Transfer Factor Classic helps your immune system recognize, respond to and remember potential health threats. It contains 4Life Transfer Factor® (immune system messenger molecules) from cow colostrum to help educate immune cells. Our classic formula has been shown to bolster Natural Killer (NK) cell activity in the presence of a health threat.† Take three (3) capsules daily to educate your immune system.