CalcMyPeptide
AntimicrobialAlso known as: Human Neutrophil Peptide 1, HNP-1, DEFA1

α-Defensin 1 (HNP-1)

α-Defensin 1 (HNP-1) is a terrifyingly efficient, endogenous biochemical weapon manufactured directly by human neutrophils. Stored heavily within azurophilic granules, it acts as the immune system's absolute first line of brutal physical defense against invading pathogens. In elite immunology research, it is studied for its ability to literally shred bacterial membranes and violently bridge the gap between innate reaction and adaptive immune memory.

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

Quick Stats

Half-LifeShort — minutes to hours in circulation
Dose RangeResearch only
FrequencyPer study protocol
Vial Sizes1 mg
BioavailabilityTopical / IV (research)
Year Developed1985

Scientific Data

Molecular Formula
C147H229N45O40S6
Molecular Weight
3441.9 g/mol
Developer
Endogenous — isolated/synthesized for research

Mechanism of Action

Human Defensin Alpha-1 (HNP-1, Human Neutrophil Peptide-1) is a cationic antimicrobial peptide (AMP) produced by neutrophils and Paneth cells. It kills bacteria, fungi, and enveloped viruses by inserting into microbial membranes and creating pores. Simultaneously, it acts as a chemoattractant for dendritic cells and T cells, bridging innate and adaptive immunity. Research interest spans wound care, antiviral protection, cancer immunomodulation, and potential gut mucosal defense.

Source: PMID: 12379468

Dosing Protocol

Typical DoseResearch only
FrequencyPer study protocol
Half-Life~2-4 hours (estimated)
Common Vial Sizes1 mg

Dosing Protocols

Research Use

Dose
Variable (µg range)
Frequency
In vitro / topical / IV (animal models)
Note: No established human therapeutic dose.

Administration

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

Expected Timeline

Immediate (in vitro)
Rapid membrane disruption of gram-positive and gram-negative bacteria.

Who Is It For?

Antimicrobial / Immune Modulation

Emerging

Potent AMP with immunomodulatory properties — research-stage only.

Safety & Considerations

Research peptide only. No established human dosing protocol. In vitro and animal studies indicate cytotoxicity at high concentrations — selectivity for pathogens vs host cells is dose-dependent.

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

α-Defensin 1 (HNP-1)— Dosing Guide
Dose Range
Research only
Half-Life
~2-4 hours (estimated)
Frequency
Per study protocol
Route
Oral
1 mg vial
Antimicrobialcalcmypeptide.com

Frequently Asked Questions

What is defensin alpha-1 used for in research?▼
HNP-1 is studied for antimicrobial applications (antibiotic alternatives), antiviral defense, wound healing, and cancer immunotherapy adjuncts. It is not used clinically in humans as a standalone therapeutic.

References

  1. Ganz T “"Human defensin-1 and -2: biological properties and functional activity".” Science (1985). PMID: 6242282

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