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Lactoferrin Side Effects & Safety

Evidence:Moderate
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This content is for informational purposes only and does not constitute medical advice. Statements about dietary supplements have not been evaluated by the FDA and are not intended to diagnose, treat, cure, or prevent any disease. Individual results may vary — consult your healthcare provider before starting any supplement. Full disclaimer

Safety Profile

Overall safety rating: Generally Safe

Potential Side Effects

  • Very well-tolerated with an excellent safety profile
  • Rare mild GI symptoms (bloating, diarrhea) at higher doses
  • Not suitable for individuals with confirmed cow milk protein allergy
  • No significant adverse effects in clinical trials even at high doses

Drug & Supplement Interactions

  • Iron supplements — lactoferrin enhances iron absorption; may need to adjust iron supplement dose
  • Antibiotics — potential synergistic antimicrobial effects; lactoferrin may enhance antibiotic activity
  • Antifungals — lactoferrin has additive antifungal effects and may enhance azole antifungal efficacy

Maximum Dose

Do not exceed: Clinical studies have used up to 3000mg/day without serious adverse effects

Full Lactoferrin Guide

References

  1. ReviewLegrand D, Elass E, Carpentier M, Mazurier J (2005). Lactoferrin: a modulator of immune and inflammatory responses. Cellular and Molecular Life Sciences. DOI PubMed
  2. Meta-analysisMayorga V, Navarro R, Roldan V, Urtecho M, et al. (2025). Efficacy of lactoferrin supplementation in pediatric infections: a systematic review and meta-analysis.. Biochemistry and cell biology = Biochimie et biologie cellulaire. DOI PubMed
  3. Wang Y, Florez ID, Morgan RL, Foroutan F, et al. (2023). Probiotics, Prebiotics, Lactoferrin, and Combination Products for Prevention of Mortality and Morbidity in Preterm Infants: A Systematic Review and Network Meta-Analysis.. JAMA pediatrics. DOI PubMed
  4. Yami HA, Tahmoorespur M, Javadmanesh A, Tazarghi A, et al. (2023). The immunomodulatory effects of lactoferrin and its derived peptides on NF-κB signaling pathway: A systematic review and meta-analysis.. Immunity, inflammation and disease. DOI PubMed
  5. Meta-analysisBerthon BS, Williams LM, Williams EJ, Wood LG (2022). Effect of Lactoferrin Supplementation on Inflammation, Immune Function, and Prevention of Respiratory Tract Infections in Humans: A Systematic Review and Meta-analysis.. Advances in nutrition (Bethesda, Md.). DOI PubMed
  6. Zhao X, Zhang X, Xu T, Luo J, et al. (2022). Comparative Effects between Oral Lactoferrin and Ferrous Sulfate Supplementation on Iron-Deficiency Anemia: A Comprehensive Review and Meta-Analysis of Clinical Trials.. Nutrients. DOI PubMed
  7. Meta-analysisAli AS, Hasan SS, Kow CS, Merchant HA (2021). Lactoferrin reduces the risk of respiratory tract infections: A meta-analysis of randomized controlled trials.. Clinical nutrition ESPEN. DOI PubMed
Show 4 more references
  1. Meta-analysisRazak A, Hussain A (2021). Lactoferrin Supplementation to Prevent Late-Onset Sepsis in Preterm Infants: A Meta-Analysis.. American journal of perinatology. DOI PubMed
  2. Ponzini E, Scotti L, Grandori R, Tavazzi S, et al. (2020). Lactoferrin Concentration in Human Tears and Ocular Diseases: A Meta-Analysis.. Investigative ophthalmology & visual science. DOI PubMed
  3. Dai C, Jiang M, Sun MJ, Cao Q (2020). Fecal Lactoferrin for Assessment of Inflammatory Bowel Disease Activity: A Systematic Review and Meta-Analysis.. Journal of clinical gastroenterology. DOI PubMed
  4. Abu Hashim H, et al. (2022). Role of lactoferrin in preventing preterm birth and pregnancy complications: a systematic review.. Reproductive sciences. DOI PubMed