Lactoferricin

lactoferricin B (bovine, LfcinB), lactoferricin H (human), hLF1-11 (human lactoferrin residues 1–11), lactoferrampin; parent protein lactoferrin (bLf, hLf)

Antimicrobial & antiviral

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Summary

Class: Short cationic antimicrobial peptides released from the N-terminal region of lactoferrin, an iron-binding glycoprotein naturally present in milk and secretions; naturally occurring fragments
Mechanism: Cationic peptides that bind and disrupt microbial membranes and sequester iron bacteria need; the parent protein also modulates immunity
Routes studied: Lactoferrin protein: oral (supplements, infant formula). Lactoferricin peptides: topical/in-vitro; hLF1-11 given intravenously in a Phase 1 trial
Half-life: Short; small cationic peptides are cleared rapidly
Storage: Research/clinical peptide; lactoferrin supplements are shelf-stable powders
Regulatory status: Lactoferrin (protein) is a permitted food ingredient in many countries; lactoferricin peptides are not approved medicines

Doses are as reported in studies or by the community — never recommendations.

1What it is

Lactoferrin is an iron-binding protein found in milk, tears, saliva and other secretions, and in the granules of neutrophils. When lactoferrin is partly digested (for example by stomach pepsin), it releases short peptides from its N-terminal end that are more potently antimicrobial than the whole protein. The best known is lactoferricin B from bovine lactoferrin. A separate engineered fragment, hLF1-11 (the first 11 amino acids of human lactoferrin), has been taken furthest toward the clinic.

These are naturally derived fragments, not designed research chemicals, and the parent protein (lactoferrin) is widely sold as an oral supplement and added to some infant formulas. Self-injection of the peptides is not an established practice.

2How it's thought to work

Iron sequestration (parent protein). lactoferrin binds iron tightly, starving bacteria of a nutrient they need — a bacteriostatic effect independent of membrane damage.

Membrane disruption (peptides). lactoferricin is cationic and amphipathic; it binds the negatively charged surface of bacteria (including LPS on Gram-negatives) and permeabilises the membrane.

Immune modulation. lactoferrin and its fragments can dampen excessive inflammation (bind LPS, reduce pro-inflammatory signalling) while supporting host defence; some antiviral, antifungal and antibiofilm activity is reported.

Antitumour signals. lactoferricin shows selective toxicity to some cancer cells .

A fragment released from milk lactoferrin. Its positive charge binds bacterial lipopolysaccharide and the peptide then disrupts the membrane; it also starves bacteria of iron.Schematic — not to scale

3What the research shows

hLF1-11 safety in humans

A Phase 1 programme (van der Velden 2009, BMC Medicine) gave hLF1-11 intravenously to 56 subjects (healthy volunteers and stem-cell transplant patients): single doses up to 5 mg and 5-day courses were generally tolerated, with reversible rises in liver transaminases the main possible drug-related finding. This established safety for further study against infections in immunocompromised patients; it was not an efficacy trial. [1]

Graded C/D

Antimicrobial activity in vitro and in animals

Lactoferricin B and hLF1-11 kill a wide range of bacteria and fungi (including Candida and some resistant bacteria) and disrupt biofilms in laboratory and animal models. Translation to approved human anti-infectives has not happened.

Graded A/B

Oral lactoferrin (the protein) in people

The whole protein, as an oral supplement, has human trials in iron status, infant infection/necrotising enterocolitis prevention, and H. pylori adjunct therapy, with mixed results. These concern the protein, not the isolated peptide, and belong to the supplement literature rather than peptide self-use.

Graded C/D

Anticancer and antiviral

Selective killing of tumour cells and antiviral effects reported ; no human therapeutic use.

4Reported side effects and interactions

Literature-reported

hLF1-11 IV was generally well tolerated; the notable signal was reversible elevated liver enzymes. Oral lactoferrin is very well tolerated. No systemic safety data for lactoferricin peptides beyond the hLF1-11 programme.

Community-reported

Oral lactoferrin supplements are used widely and are low-risk. Self-injection of lactoferricin peptides: essentially none documented.

Theoretical. cationic peptides carry general host-cell toxicity concerns at high systemic concentrations.

Interactions. lactoferrin may affect iron absorption; relevant for anyone managing iron status.

Markers researchers commonly monitor

For the oral protein, no specific monitoring is standard. Where the peptides have been given in research:

Marker	Why it's watched
Liver enzymes (ALT/AST)	the hLF1-11 Phase 1 signal; the one marker the trial flagged.
Iron studies (ferritin, transferrin saturation)	because lactoferrin binds iron and affects its absorption.
CBC and CMP	general safety baseline in any injected research use.

Free for everyone. Safety information is never behind a paywall.

5Formulation and handling

Oral lactoferrin supplements are shelf-stable powders/capsules taken by mouth; no . Research peptides (lactoferricin B, hLF1-11) are handled per laboratory/clinical protocol. No calculator link — this is not an established self-injected peptide.

6Commonly studied alongside

Conventional antibiotics and antifungals (synergy), Human defensins and LL-37 (fellow host-defence peptides), probiotics (gut/immune context).

Informational cross-links. Not stack recommendations.

7Regulatory status by region

Region	Status (checked —)
United States	Lactoferrin (protein) is GRAS for certain food uses; lactoferricin peptides and hLF1-11 are not approved drugs
European Union	Bovine lactoferrin authorised as a novel food ingredient; peptides not authorised as medicines
United Kingdom	Similar to EU for the protein; peptides not licensed
Australia	Lactoferrin permitted in some foods/formula; peptides not approved
South Africa	Not separately registered as a medicine
Sport	Not listed by WADA

8Open questions

Can lactoferricin or hLF1-11 become a usable anti-infective, especially for fungal and resistant infections in immunocompromised patients?
How much of oral lactoferrin's claimed benefit survives digestion, and is it the protein or its released peptides doing the work?
What was the mechanism and significance of the transaminase rise seen with IV hLF1-11?

9References

1van der Velden WJFM et al. (2009). Safety and tolerability of the antimicrobial peptide human lactoferrin 1-11 (hLF1-11). BMC Medicine. DOI
2Gifford JL, Hunter HN, Vogel HJ (2005). Lactoferricin: a lactoferrin-derived peptide with antimicrobial, antiviral, antitumor and immunological properties. Cell Mol Life Sci. PubMed · DOI
3Bellamy W et al. (1992). Identification of the bactericidal domain of lactoferrin. Biochim Biophys Acta. PubMed · DOI
4Wakabayashi H, Yamauchi K, Takase M (2006). Lactoferrin research, technology and applications. Int Dairy J. DOI
5García-Montoya IA et al. (2012). Lactoferrin a multiple bioactive protein: an overview. Biochim Biophys Acta. PubMed · DOI

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11Page history

30 Oct 2026Profile published — awaiting medical review

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