Human tears contain approximately 1–2 mg/mL lactoferrin — making it the most abundant protein in tear fluid after albumin. Tear lactoferrin provides antimicrobial protection for the ocular surface. Levels decline significantly with dry eye disease, Sjögren's syndrome, and aging — suggesting a pathogenic role for lactoferrin deficiency in these conditions.

Are lactoferrin eye drops commercially available?

Some specialty compounding pharmacies produce lactoferrin eye drops. Commercial lactoferrin eye drops are available in Japan and some European markets. In the US, they are not yet broadly commercially available but can be compounded.

Should I take oral lactoferrin for dry eye?

Oral lactoferrin does not directly increase tear lactoferrin levels — tear fluid lactoferrin is produced by the lacrimal gland specifically. Systemic anti-inflammatory effects from oral lactoferrin may modestly benefit ocular surface inflammation contributing to dry eye. Topical eye drops are more directly effective.