I’ve spent considerable time reviewing the clinical research on lactoferrin, and it’s a genuinely interesting compound. Unlike some supplements where you’re basically hoping for a placebo effect, lactoferrin has actual biological mechanisms that researchers can point to. That said, the quality of evidence varies quite a bit depending on which benefit you’re looking at.

What is lactoferrin?

Lactoferrin is a glycoprotein belonging to the transferrin family. It weighs around 78 kDa (kilodaltons) and contains 691 amino acids. The name comes from its original discovery in milk, though scientists now know it appears in many bodily fluids.

Researchers first identified it in whey back in 1939, classifying it as a type of erythrin. It took until 1960 for scientists to properly isolate and purify it from both human and bovine milk. That’s when they confirmed it was the primary iron-binding protein in milk.

Your body produces lactoferrin through mucosal epithelial cells and neutrophils (a type of white blood cell). It shows up in most exocrine secretions including milk, tears, saliva, intestinal mucus, and genital secretions. Neutrophils store it in their specific granules as part of the innate immune response.

The iron-binding property is important here. Lactoferrin can grab onto iron ions, which has downstream effects on bacterial growth, oxidative stress, and inflammation. This mechanism underlies many of the potential benefits researchers have investigated.

What are the benefits of lactoferrin?

1. Lactoferrin may reduce respiratory infection risk

Respiratory tract infections cover a broad range of conditions affecting your airways. Upper respiratory infections include common colds, laryngitis, pharyngitis, tonsillitis, rhinitis, sinusitis, and otitis media. Lower respiratory infections include bronchitis, bronchiolitis, pneumonia, and tracheitis.

These infections drive a substantial portion of antibiotic prescriptions in general practice, somewhere around 60 percent. The NHS deals with enormous costs from this, with acute cough prescriptions alone running over £15 million annually.

A meta-analysis covering six randomised controlled trials found that lactoferrin significantly reduced respiratory infection incidence compared to controls Note 1. The proposed mechanisms involve its effects on immune function and its ability to inhibit bacterial and viral growth.

My assessment: The results look promising, but I’d note that the sample sizes were relatively small and some studies had bias concerns. This is one of those areas where the biological rationale makes sense, but we need larger, better-designed trials before making strong claims. If you’re someone who catches colds frequently, it might be worth considering, but don’t expect miracles.

2. Lactoferrin may help prevent necrotising enterocolitis in preterm infants

Necrotising enterocolitis is a serious inflammatory bowel condition that primarily affects premature babies. Risk factors include preterm birth, abnormal gut bacterial colonisation, and insufficient breastfeeding.

The condition involves varying degrees of intestinal damage, ranging from mucosal injury through to full-thickness necrosis and perforation. Symptoms can be vague and may include feeding intolerance, bowel obstruction, abdominal distension, bloody stools, lethargy, breathing difficulties, metabolic acidosis, shock, and sepsis.

A systematic review and meta-analysis examining nine randomised controlled trials with 1,834 preterm infants found that preventive lactoferrin supplementation significantly reduced late-onset sepsis and necrotising enterocolitis rates Note 2. It also appeared to lower hospital-acquired infections, infection-related deaths, time to full enteral feeding, and hospital stay length.

This is actually one of the more compelling applications for lactoferrin. The population is well-defined, the outcomes are clear, and the mechanism makes biological sense since preterm infants have underdeveloped immune systems and gut barriers. Several neonatal intensive care units have incorporated lactoferrin into their protocols, though practices vary.

3. Lactoferrin improves iron deficiency anaemia

Iron deficiency anaemia remains the most common nutritional disorder worldwide, affecting over two billion people. Pregnant women face particularly high risk, with prevalence averaging 14 percent in industrialised countries and 56 percent in developing nations.

Even mild to moderate iron deficiency during pregnancy can lead to adverse birth outcomes including preterm delivery, inappropriate birth weight, growth restriction, and in severe cases, foetal death.

A meta-analysis examining four randomised controlled trials with 600 pregnant women who had iron deficiency anaemia found that daily oral bovine lactoferrin worked as effectively as ferrous sulphate in improving haemoglobin levels Note 3. The key difference was fewer gastrointestinal side effects with lactoferrin.

This finding caught my attention because iron supplements are notorious for causing constipation, nausea, and stomach upset. If lactoferrin provides similar benefits with better tolerability, that’s genuinely useful for the many women who struggle to take traditional iron supplements. The NHS notes that iron supplementation side effects lead many patients to discontinue treatment, so alternatives matter.

4. Lactoferrin may enhance Helicobacter pylori eradication therapy

Helicobacter pylori is a gram-negative bacterium considered one of the most common bacterial infections globally. It colonises the stomach lining surface and increases risk for chronic gastritis, peptic ulcer disease, gastric mucosa-associated lymphoid tissue lymphoma, and gastric adenocarcinoma.

Standard eradication treatment involves triple therapy: a proton pump inhibitor combined with amoxicillin and clarithromycin. However, antibiotic resistance has become an increasing problem, reducing treatment effectiveness in many populations.

A meta-analysis of nine randomised controlled trials involving 1,343 participants found that adding lactoferrin to standard H. pylori eradication therapy both increased eradication rates and reduced drug side effects like nausea Note 4.

The mechanism likely involves lactoferrin’s iron-binding properties. H. pylori needs iron to survive and multiply, so lactoferrin may essentially starve the bacteria while the antibiotics do their work. It’s a reasonable adjunct therapy, though I’d emphasise it supplements rather than replaces proper medical treatment. If you’re dealing with confirmed H. pylori infection, work with your doctor on the full treatment protocol.

5. Lactoferrin may help regulate stress responses

Stress occurs when environmental demands exceed your adaptive capacity. Not all stress is harmful. Brief, manageable stress can enhance performance and focus. Problems arise when stress becomes chronic or overwhelming, exhausting your physiological systems.

A double-blind, placebo-controlled trial studied 18 healthy female university students and found that oral lactoferrin helped regulate autonomic nervous system activity compared to placebo Note 5. Specifically, heart rate variability measurements showed parasympathetic upregulation and sympathetic downregulation.

I should be honest about this one. The sample size of 18 participants is quite small, and the study only looked at healthy young women. We can’t extrapolate these findings to broader populations or assume the effects are meaningful in real-world stress scenarios. The biological mechanism involving gut-brain axis communication is plausible, but this needs substantially more research before drawing conclusions.

6. Lactoferrin may improve mild to moderate acne

Acne is a chronic inflammatory condition affecting the hair follicle sebaceous units. It’s among the most common skin conditions, primarily affecting adolescents though it can occur at any age.

Symptoms range from increased sebum production and comedones (blackheads and whiteheads) to inflammatory papules, pustules, and in severe cases, nodules and cysts. Scarring and pigmentation changes can result from more severe presentations.

The pathogenesis involves abnormal hair follicle keratinisation, increased sebum production driven by androgens, and overgrowth of Propionibacterium acnes bacteria. These factors interact in ways researchers are still working out.

A randomised, double-blind, placebo-controlled trial followed 168 patients with mild to moderate acne over three months. The treatment group received oral lactoferrin combined with vitamin E and zinc. Results showed improvements in total lesion count, inflammatory lesions, and sebum levels Note 6.

One limitation here is that the treatment combined three active ingredients, making it difficult to attribute effects specifically to lactoferrin. Zinc alone has established benefits for acne. Still, the combination approach reflects how supplements often work best in practice rather than as isolated compounds.

Are there any side effects of lactoferrin?

At moderate doses, lactoferrin appears safe for most people. Reported side effects include diarrhoea, skin rash, dizziness, headache, reduced appetite, fatigue, chills, and constipation. These occur more frequently at higher doses.

The Mayo Clinic notes that lactoferrin from bovine sources has been used safely in research at doses up to 4.5 grams daily for up to a year. However, most supplements contain much lower amounts, typically 100 to 500 mg per dose.

Since lactoferrin comes primarily from cow’s milk, anyone with dairy allergies should exercise caution. Cross-reactivity is possible even with purified supplements.

Safety precautions (2 contraindications to use)

1. Avoid if you have iron overload conditions

Because lactoferrin enhances iron absorption, people with haemochromatosis or other conditions causing elevated blood iron should avoid supplementation. Adding more iron when levels are already high can damage organs including the liver and heart.

2. Consult a healthcare provider in specific circumstances

The following groups should seek medical advice before using lactoferrin supplements:

People with impaired liver or kidney function
Pregnant or breastfeeding women
Children under 18 years
Anyone taking prescription medications (potential interactions)

This isn’t an exhaustive list. Whenever you’re considering a new supplement, particularly if you have existing health conditions or take medications, speaking with a healthcare provider is worthwhile. They can assess your individual situation and potential interactions that might not be obvious from general guidance.

Summary

Lactoferrin is one of the more scientifically interesting supplements out there. Its iron-binding properties give it real biological effects that go beyond wishful thinking. The evidence is strongest for preventing infections in preterm infants and as an adjunct to iron supplementation during pregnancy. Benefits for respiratory infections, H. pylori treatment, stress regulation, and acne have supporting research but need larger, better-designed studies.

For urinary tract health, lactoferrin’s antimicrobial properties may offer some protection against bacterial infections, though direct evidence for UTI prevention is limited. Its presence in normal urinary secretions suggests it plays some role in the body’s natural defence against pathogens in the urogenital tract.

As with any supplement, lactoferrin works best as part of a broader health strategy rather than a standalone solution. The research is promising in several areas, but managing expectations is important. Talk to your doctor if you’re considering supplementation, particularly if you have existing health conditions.

References

Lactoferrin supplementation and respiratory tract infections: A meta-analysis (2021) - PubMed
Lactoferrin and necrotizing enterocolitis prevention in preterm infants: Systematic review (2018) - PubMed
Bovine lactoferrin versus ferrous sulfate for iron deficiency anemia in pregnancy (2017) - PubMed
Lactoferrin as adjunct to Helicobacter pylori eradication therapy: Meta-analysis (2009) - PubMed
Lactoferrin effects on autonomic stress responses (2018) - PubMed Central
Lactoferrin, vitamin E and zinc for acne treatment (2017) - PubMed