What lactoferrin actually does
What people take it for, and how much of it holds up.
Short answer
The strongest evidence is for iron deficiency, where lactoferrin performs about as well as iron tablets with fewer stomach problems. Most other claims come from laboratory work rather than trials in people. One of the best-known claims, preventing infection in premature babies, was tested in a large trial and did not hold up.
Where it does reasonably well
Iron deficiency is the strongest case. Trials in pregnant women with iron deficiency anemia have compared lactoferrin against ordinary iron tablets and found similar improvement in blood counts, with noticeably fewer digestive complaints. That last part matters more than it sounds: plenty of people abandon iron tablets because of how they feel on them, and a treatment that actually gets taken beats one that does not.
Put a number on “small”: the pooled analysis covers four trials and 600 women in total, and the advantage it found was concentrated in one of them. The dose used was 100 mg twice a day. This is treatment of diagnosed deficiency under supervision, not a reason for anyone to take it generally.
Where the evidence runs out
Most of what is claimed for lactoferrin comes from work in cells or in animals. That research is real and often interesting, but a compound that slows bacterial growth in a dish has not thereby been shown to do anything for a person. The distance between those two statements is the whole problem with how this subject usually gets written about.
The one that was tested and failed
Several small trials suggested lactoferrin prevented infections in very premature babies. It was a plausible idea and the early results agreed with each other. A much larger trial then tested it properly in 2,203 infants across 37 UK hospitals, and found no reduction in infection at all. Infections occurred in 29% of the lactoferrin group and 31% of the group given a placebo, a difference well inside the range you would expect from chance.
That is worth knowing for two reasons. It is the answer for that specific use. And it is a clean illustration of why a run of small promising trials is not the end of a story.
More answers are being added to this section.
Where this comes from
- Abu Hashim H, Foda O, Ghayaty E. Lactoferrin or ferrous salts for iron deficiency anemia in pregnancy: a meta-analysis of randomized trials. Eur J Obstet Gynecol Reprod Biol 2017;219:45-52 — four trials, 600 women, pooled
- Paesano R, et al. Efficacy and tolerability of oral bovine lactoferrin compared to ferrous sulfate in pregnant women with iron deficiency anemia. Acta Obstet Gynecol Scand 2009;88(8):931-7 — the dose used: 100 mg twice a day
- ELFIN trial investigators group. Enteral lactoferrin supplementation for very preterm infants: a randomised placebo-controlled trial. Lancet 2019;393(10170):423-433 — the 2,203-infant trial that found no effect
This page is general information, not medical advice, and not a recommendation to take anything. It cannot interpret your test result. Lactoferrin supplements are made from cow's milk and are unsuitable if you have a milk protein allergy. If you are pregnant, breastfeeding, giving anything to an infant, or being treated for a health condition, talk to a doctor or pharmacist first.