Lactoferrin

How it works

Lactoferrin is a glycoprotein found in milk, tears and saliva, and it is part of innate immune defence. Its main trick is iron sequestration: bacteria need free iron to grow, lactoferrin binds it with high affinity, and growth slows for want of a nutrient rather than through a toxic effect. That is a gentler mechanism than a conventional antimicrobial and does not carry the same resistance pressure.

It has secondary actions too — direct binding to bacterial membranes, and modulation of inflammatory signalling, which is why the anti-inflammatory description keeps appearing alongside the antibacterial one.

The evidence

This is where care is needed, because the widely cited acne result is oral. Trials giving lactoferrin-enriched fermented milk by mouth reported meaningful reductions in inflammatory lesions over several weeks. That is a real finding and it is not evidence for a topical serum: swallowing a protein that modulates gut and systemic immunity is a different intervention from applying it to the stratum corneum.

Topical work exists and is early — small studies and in vitro activity against C. acnes and S. aureus. Reasonable, unproven at the level the marketing implies, and worth treating as supportive rather than as a treatment.

Suitability

• Acne-prone and inflamed skin, alongside a real acne active
• Sensitive skin: well tolerated, no stinging, no barrier cost
• Vegans: not suitable — it is milk-derived, unless a recombinant version is specified

Concentration

Rarely disclosed. As a protein it is also fragile: heat and extreme pH denature it, so formulation quality matters more than the number on the label.

Conflicts & combinations

No conflicts. It sits comfortably beside niacinamide and zinc for oily, inflamed skin. One point worth stating for anyone with a dairy allergy: this is a milk protein, and while cosmetic-grade material is highly purified, a genuine milk-protein allergy is a reason to avoid rather than to test casually.