Lactoferrin is a large glycoprotein (molecular weight ~80 kDa) that is partially denatured by gastric acid (pH 1-2). The degree of protection afforded by different supplement forms matters significantly for applications requiring intact lactoferrin at specific anatomical sites — particularly gut-targeted applications versus systemic immune support.

Lactoferrin in standard capsules encounters gastric acid immediately. Studies estimate that 30-60% of lactoferrin protein is denatured by gastric acid at pH 2, depending on gastric pH, retention time, and stomach fullness. However, partially denatured lactoferrin retains significant biological activity — many of its peptide fragments (lactoferricin, lactoferrampin) have independent antimicrobial and immunomodulatory activity. Standard capsules are appropriate for systemic applications (immune support, iron absorption, anti-inflammatory effects) where some gastric processing is acceptable.

Enteric coating (typically using pH-sensitive polymer coatings like hydroxypropyl methylcellulose phthalate) protects lactoferrin through the low-pH stomach environment and releases it at duodenal pH (>6). This delivers significantly more intact lactoferrin to the small intestine. Enteric coating is preferred for gut-targeted applications (IBD, IBS, H. pylori eradication, leaky gut), iron absorption (which occurs primarily in the duodenum), and for individuals with low gastric acid production (common in older adults, PPI users).

Liposomal encapsulation theoretically protects lactoferrin through the GI tract and may enhance cellular uptake. However, few clinical trials have specifically validated liposomal lactoferrin's superiority over enteric-coated forms in humans. Liposomal products typically cost significantly more. Until clinical validation of superior efficacy is available, enteric-coated formulations offer a better-evidenced alternative.