Evidence Level
Lactoferrin has a robust evidence base across multiple immune mechanisms. Legrand et al. (2005) published a comprehensive review of lactoferrin's antimicrobial and immune-modulating properties, confirming its role in innate immunity through iron sequestration, direct membrane disruption, and immune cell activation. Paesano et al. (2006) conducted an RCT showing bovine lactoferrin was as effective as ferrous sulfate for treating iron deficiency anemia in pregnant women, with superior tolerability. The antiviral mechanism — blocking viral attachment to cell surface glycosaminoglycans — has been demonstrated for multiple virus families in in vitro studies. Lactoferrin is one of the few supplements that simultaneously supports immune defense, gut health, and iron status.