Lactoferrin and the Immune System: How It Works
Lactoferrin is a glycoprotein that is present in human milk and cow milk. Lactoferrin is found in abundance in mammalian milk. The lactoferrin found in cow milk is known as Bovine Lactoferrin. [1] Lactoferrin is present in...
Lactoferrin is an iron-binding glycoprotein that sits at the front line of the immune system. It is stored in neutrophils, the first white blood cells to reach a site of infection, and it coats the mucosal surfaces of the gut, airways, eyes and urinary tract where the body meets the outside world.
That distribution is the clearest signal of what it does. Research describes lactoferrin as an immunomodulator rather than an immune stimulant: it is studied for moderating excessive inflammatory signalling while supporting the mechanisms that clear pathogens. This article summarises published research and is not a claim about the effects of our product.
What human trials report
The most comprehensive synthesis available is a 2022 systematic review and meta-analysis published in Advances in Nutrition, covering 25 studies, 19 of them randomised controlled trials, across adults, children and infants. Doses ranged from 32.4 mg to 3 g per day, with a median of 225 mg/day, over periods of 1 to 60 weeks.
- Inflammation: 8 of 13 studies reported a reduction in at least one systemic inflammatory biomarker. Pooled analysis showed interleukin-6 reduced by a mean difference of 24.9 pg/mL (95% CI 41.64 to 8.08).
- Immune function: improved in 6 of 8 studies that measured it.
- Respiratory outcomes: the clearest signal was in infants and children (OR 0.78; 95% CI 0.61 to 0.98). In adults the pooled estimate was neutral, which the authors identify as a priority for further study given how few adult trials were available at the time.
The review authors concluded that 200 mg of lactoferrin per day reduces systemic inflammation. That figure matters, because it is close to the dose most adult supplements provide.
Five ways lactoferrin interacts with immune function
1. Bridging innate and adaptive immunity
Lactoferrin supports the leukocyte immune system by assisting the activity of natural killer cells, supporting neutrophil function and helping modulate the production of reactive oxygen species. It also supports macrophage activity through cytokine and nitric oxide production.
2. Antioxidant activity through iron binding
Free iron catalyses the Fenton reaction, which generates hydroxyl radicals. By keeping iron bound and unavailable, lactoferrin helps prevent those radicals forming rather than neutralising them afterwards. This is why its antioxidant behaviour is inseparable from its iron chemistry.
3. Supporting a healthy inflammatory response
Lactoferrin is found in serum and is involved in the body's natural inflammatory signalling. The interleukin-6 reduction reported in the meta-analysis above is the clearest human evidence of this, and it connects directly to iron: IL-6 drives hepcidin upward, and elevated hepcidin locks iron in storage.
4. T-cell mediated responses
All T-cell subsets express lactoferrin receptors. Both human and bovine lactoferrin bind these receptors and help modulate T-cell activity depending on the stage of maturation, activation or differentiation. Research describes effects on antigen-specific T-cell responses that can persist for several weeks after initial sensitisation.
5. B-cell mediated responses
Lactoferrin supports the maturation of immature B-cells by increasing C3R expression and supporting acquisition of surface IgD. Orally administered bovine lactoferrin has been associated with secretion of IgA and IgG, meaning it acts on both arms of the adaptive response.
Summary of mechanisms
| Mechanism | What research describes |
| Support for natural defences | Attributed in part to iron-binding properties, which influence the local environment at mucosal surfaces. |
| Immune cell activity | Supports activity of neutrophils, monocytes and natural killer cells, which form part of the body's natural defences. |
| Inflammatory balance | Associated with reduced interleukin-6 across pooled human trial data. |
| Iron binding and transport | Influences iron availability. This is lactoferrin's best-studied natural function. |
| Antioxidant activity | Prevents free iron catalysing the formation of reactive oxygen species. |
How much has been studied
Across the reviewed literature, doses ranged from 32.4 mg to 3 g per day with a median of 225 mg. Adult trials cluster around 200 to 300 mg per day. Duration matters as much as dose: most trials reporting an effect ran 8 to 12 weeks or longer, with a median of 12 weeks. Studies shorter than about four weeks rarely show much, because the processes involved are gradual.
For the full evidence base across every health area, with each study's population, dose and duration stated, see our review of the bovine lactoferrin research.
Where lactoferrin comes from
Colostrum, the first milk produced after birth, contains the highest concentration. Bovine lactoferrin is purified from cow's milk and is the form used in almost all the research above. It is available as bovine lactoferrin capsules in a 300mg delayed-release format, or as bovine lactoferrin powder if you prefer to mix it into food or drinks.
Frequently asked questions
How much lactoferrin is used in immune research?
The 2022 meta-analysis identified 200 mg per day as the dose associated with reduced systemic inflammation. The median across all 25 studies was 225 mg per day.
How long does it take?
Most trials reporting an effect ran 8 to 12 weeks or longer. The median study duration was 12 weeks.
Does lactoferrin work differently in children and adults?
The pooled data show the clearest respiratory benefit in infants and children. Adult trials were fewer at the time of the review, and several have been published since.
Is lactoferrin safe?
Bovine milk lactoferrin holds GRAS status in the United States, and studies using 1.5 g to 15 g per day for up to 42 weeks have not found significant toxicity-related outcomes. It is a milk-derived protein, so it is unsuitable for anyone with a dairy allergy. See our safety and tolerability summary.
Can I take it with other supplements?
Because lactoferrin interacts with iron metabolism, anyone taking prescribed iron should discuss it with the prescribing clinician first.
References
- Berthon BS, et al. Effect of Lactoferrin Supplementation on Inflammation, Immune Function, and Prevention of Respiratory Tract Infections in Humans: A Systematic Review and Meta-analysis. Adv Nutr. 2022. PMID 35481594
- Legrand D. Overview of Lactoferrin as a Natural Immune Modulator. J Pediatr. Full text
- Kell DB, et al. The Biology of Lactoferrin, an Iron-Binding Protein. Front Immunol. Full text
- Actor JK, Hwang SA. Lactoferrin as a natural immune modulator. PMID 19519436
- Kruzel ML, et al. Lactoferrin in a Context of Inflammation. Front Immunol. Full text
- Hwang SA, Actor JK. Lactoferrin as a Natural Immune Modulator. PMC2915836
This information summarises published research and is provided for education. It is not medical advice and not a claim about the effects of any Lactoferrin Co. product. Contains milk. Consult a qualified healthcare professional before starting any supplement.