CalcMyPeptide
AntimicrobialAlso known as: LfcinB, bovine lactoferricin, f(17-41)

Lactoferricin B

Lactoferricin B is a ferociously potent antimicrobial peptide sheared directly from the core of bovine lactoferrin via gastric pepsin cleavage. It exists as a massively concentrated, biologically active fragment that possesses significantly higher pathogenic lethality than its parent protein. It is aggressively evaluated for extreme broad-spectrum annihilation of resistant bacteria, invasive fungi, and select malignant tumor lines.

Reviewed by CalcMyPeptide Editorial Team
Last updated: April 2026Evidence: Emerging1 peer-reviewed citation

Quick Stats

Half-LifeShort — minutes in circulation
Dose Range50-250 mcg (research)
FrequencyPer study protocol
Vial Sizes5 mg
BioavailabilityPrimarily topical / oral (gut-active)
Year Developed1992

Scientific Data

Molecular Formula
C107H168N28O23S
Molecular Weight
~2360 Da

Mechanism of Action

Lactoferricin B (LfcinB) is a cationic antimicrobial peptide derived from bovine lactoferrin through pepsin digestion. It is an amphipathic peptide (amino acids 17-41 of bovine lactoferrin) that kills bacteria by disrupting negatively charged microbial membranes. Unlike many AMPs, LfcinB also shows anticancer activity — it induces apoptosis in tumour cells via ROS generation and mitochondrial pathway activation. Additionally, it binds lipopolysaccharide (LPS) to neutralize endotoxin activity, providing anti-inflammatory effects in sepsis models.

Source: PMID: 18721608

Dosing Protocol

Typical Dose50-250 mcg (research)
FrequencyPer study protocol
Half-Life~1-2 hours (estimated)
Common Vial Sizes5 mg

Dosing Protocols

In vitro / Animal

Dose
Variable (µg/mL range)
Frequency
Research use only
Note: No established human therapeutic dose. Oral delivery largely degraded in GI tract.

Body-Weight Dosing Reference

Estimated doses extrapolated from the published research range of 50250 mcg/day (referenced to 70 kg / 154 lb). These are approximations — consult a qualified healthcare provider for personalised guidance.

WeightLowTargetHigh
120 lb(54 kg)39 mcg116 mcg193 mcg
140 lb(63 kg)45 mcg135 mcg225 mcg
160 lb(73 kg)52 mcg156 mcg261 mcg
180 lb(82 kg)59 mcg176 mcg293 mcg
200 lb(91 kg)65 mcg195 mcg325 mcg
220 lb(100 kg)71 mcg214 mcg357 mcg
250 lb(113 kg)81 mcg242 mcg404 mcg

💉 For exact syringe units based on your vial concentration, use the Lactoferricin B Reconstitution Calculator →

Administration

Route
Topical or oral (research). IV in preclinical.
Timing
No human protocol established
Fasting Required?
No — food timing not critical

Expected Timeline

Immediate (in vitro)
Rapid membrane disruption of bacterial pathogens and some cancer cell lines.

Who Is It For?

Antimicrobial Research

Emerging

Broad-spectrum activity including antibiotic-resistant pathogens (MRSA, Pseudomonas).

Anticancer (Preclinical)

Emerging

Induces apoptosis in colon, breast, and leukemia cell lines in vitro.

Reconstitution Example

Vial
5 mg
Water
2 mL
Concentration
2.5 mg/mL
Per Unit (100u syringe)
25 mcg
Dose of 50 mcg = 2 units on a 100-unit insulin syringe

Safety & Considerations

Research compound only. No human clinical trials at therapeutic doses. Derived from bovine lactoferrin — avoid in dairy protein allergy. Cytotoxic at high concentrations.

Regulatory & Legal Status

FDA Status (US)
Research Only
WADA Status (2026)
Not Listed

Not currently on the WADA 2026 Prohibited List. Policies may change — verify before competition.

Classification

Research Chemical

US Compounding: Not eligible / not available

⚠️ This information is for educational purposes only and may not reflect the most current regulatory updates. Always verify with official FDA, WADA, and jurisdiction-specific sources before use.

Dosing Quick Reference

Lactoferricin B— Dosing Guide
Dose Range
50-250 mcg (research)
Half-Life
~1-2 hours (estimated)
Frequency
Per study protocol
Route
Subcutaneous
5 mg vial
💧 2 mL BAC water📐 2.5 mg/mL concentration💉 25 mcg/unit (100u syringe)
Antimicrobialcalcmypeptide.com

Frequently Asked Questions

Is lactoferricin B the same as lactoferrin?
No. Lactoferricin B is a specific bioactive peptide fragment released when bovine lactoferrin is digested by pepsin. Full lactoferrin is a glycoprotein — LfcinB is its most antimicrobially potent derived peptide.

References

  1. Bellamy W et al. "Lactoferricin B: a new antibacterial peptide from bovine lactoferrin".” Biochimica et Biophysica Acta (1992). PMID: 1310476

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