Lactoferricin B vs LL-37 — Peptide Comparison

For education only

This guide cannot diagnose a condition or recommend a personal treatment plan. Discuss medical questions with a qualified professional.

At a Glance

Quickcomparison

Dose Range

Lactoferricin B

1–10 mg

LL-37

0.5–1.6 mg/mL (topical)

Frequency

Multiple times daily

Once daily

Administration

Oral (research — resistant to gastric digestion)

Topical application (wound healing)

Cycle Length

4-6 weeks

12+ weeks

Onset Speed

Rapid (hours to days)

Moderate (1-2 weeks)

Evidence Level

Moderate human trials (Phase 1-2)

Efficacy

Benefitratings

Fighting Germs

Cancer Cell Targeting

Immune Support

Wound Healing

Fighting Infections

Immune Boost

Technical Data

Compoundspecifications

Molecular Formula

Approximately C142H224N46O34S2 (varies slightly by reported sequence)

Molecular Weight

~3,126 Da (25-amino-acid bovine lactoferricin B)

Half-Life

Plasma half-life: minutes (proteolytic degradation); gastrointestinal persistence: hours (relative resistance to trypsin and chymotrypsin compared to unstructured peptides); beta-sheet structure and disulfide bond provide moderate protease resistance

Bioavailability

Generated endogenously during gastric digestion of dietary lactoferrin; partially resistant to further proteolytic degradation due to beta-sheet structure and disulfide bond; systemic bioavailability limited by intestinal proteases and hepatic metabolism

CAS Number

146897-68-9

C205H340N60O53

4,493.26 Da

Short systemic half-life (minutes) due to protease susceptibility; local tissue persistence at wound sites is longer due to binding to extracellular matrix components and lipid membranes

Topical application achieves high local wound-bed concentrations; systemic bioavailability limited by rapid proteolytic degradation and serum protein binding; not intended for oral delivery

154947-66-7

Protocols

Dosingtiers

starting

0.5 mg/mL gel

Twice weekly

4 weeks

Lowest dose in the LL-37 (ropocamptide) Phase I/IIa venous leg-ulcer trial and the most effective: ~6-fold faster healing and ~68% ulcer-area reduction vs placebo, applied to the wound twice weekly [4].

standard

1.6 mg/mL gel

Mid dose in the same trial; ~3-fold improvement and ~50% area reduction vs placebo. The highest tested concentration (3.2 mg/mL) showed no benefit over placebo, so dose escalation above this is not supported [4].

Applications

Bestsuited for

Research into dairy-derived antimicrobial peptides and natural innate defense mechanisms

Lactoferricin B is particularly well-suited for individuals focused on research into dairy-derived antimicrobial peptides and natural innate defense mechanisms. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.

Investigation of structure-activity relationships in beta-sheet antimicrobial peptides

Lactoferricin B is particularly well-suited for individuals focused on investigation of structure-activity relationships in beta-sheet antimicrobial peptides. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.

Preclinical development of anticancer peptides targeting membrane phospholipid asymmetry

Lactoferricin B is particularly well-suited for individuals focused on preclinical development of anticancer peptides targeting membrane phospholipid asymmetry. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.

Understanding the gastrointestinal antimicrobial defense provided by dietary lactoferrin digestion

Lactoferricin B is particularly well-suited for individuals focused on understanding the gastrointestinal antimicrobial defense provided by dietary lactoferrin digestion. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.

Treatment of chronic non-healing wounds including venous leg ulcers and diabetic ulcers

LL-37 is particularly well-suited for individuals focused on treatment of chronic non-healing wounds including venous leg ulcers and diabetic ulcers. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.

Immune defense against antibiotic-resistant bacterial infections (MRSA, Pseudomonas)

LL-37 is particularly well-suited for individuals focused on immune defense against antibiotic-resistant bacterial infections (mrsa, pseudomonas). Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.

Anti-biofilm strategies for chronic wound infections and medical device-associated infections

LL-37 is particularly well-suited for individuals focused on anti-biofilm strategies for chronic wound infections and medical device-associated infections. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.

Boosting innate immune defense in immunocompromised or aging individuals

LL-37 is particularly well-suited for individuals focused on boosting innate immune defense in immunocompromised or aging individuals. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.

Safety Profile

Sideeffects

Common

Mild GI discomfort

Bitter taste

Local irritation (topical use)

Mild flatulence

Uncommon

Allergic reaction in milk-sensitive individuals

Serious

Hemolytic activity at high concentrations

Local site irritation

Transient stinging or burning

Mild perilesional erythema

Increased wound exudate

Allergic contact reaction

Hemolytic activity at systemic concentrations

Research Status

Safety& evidence

FDA Status

Research compound

Safety Overview

Lactoferricin B is a 25-amino acid peptide fragment of human lactoferrin with a well-documented natural history—derived from a dietary protein that humans consume in breast milk and dairy products. Preclinical studies show excellent tolerability with no hepatotoxicity, nephrotoxicity, or genotoxicity in animal models even at supraphysiological doses. The antimicrobial and antifungal mechanism (iron sequestration and membrane disruption) appears selective for pathogenic microorganisms with minimal effect on commensal bacteria at therapeutic concentrations.

Contraindications

xKnown allergy to bovine milk proteins or lactoferrin — cross-reactivity possible

xPregnancy and breastfeeding — insufficient safety data for therapeutic-dose lactoferricin supplementation

xActive hemolytic conditions — at higher concentrations lactoferricin shows some hemolytic activity that may worsen hemolysis

xIron overload conditions (hemochromatosis) — lactoferricin retains some iron-binding capacity from the parent lactoferrin molecule

LL-37 is an endogenous cathelicidin antimicrobial peptide naturally produced by immune cells and epithelial tissues, conferring inherent biocompatibility and low toxicity at physiological concentrations. Synthetic LL-37 shows excellent safety in in vitro immune assays and animal models with no hepatotoxicity, nephrotoxicity, or genotoxicity at relevant doses. At elevated concentrations, the cationic amphipathic structure can cause hemolysis and cell membrane damage, but therapeutic doses are far below these thresholds. Injection site reactions are minimal in research applications.

xKnown hypersensitivity to cathelicidin peptides or formulation components

xActive hemolytic conditions — LL-37 demonstrates concentration-dependent hemolytic activity

xPregnancy and breastfeeding — insufficient reproductive safety data from clinical trials

xSevere renal impairment — peptide clearance may be altered

Decision Guide

Which isright for you?

Choose Lactoferricin B if...