58 South Molton Street, Mayfair, W1K 5SL London

Remarkable Molecule

LL-37 Peptide: A Multifaceted Peptide

The LL-37 peptide, also known as cathelicidin antimicrobial peptide (CAMP), is a remarkable molecule in the realm of host defence peptides (HDPs). 

In summary, LL-37 was discovered in the late 1990s, and has been the focus of extensive research due to its potent antimicrobial properties and diverse range of biological functions. 

If you are new to the realm of cutting-edge peptides and their potential applications, you can explore our Peptide Therapy introduction guide and also book a consultation with us to learn more about Peptide therapy homepage.

This article delves into the multifaceted world of LL-37, shedding light on its structure, mechanisms of action, and its broader implications in various aspects of human health.

Potent Antimicrobial Properties

What is it?

LL-37 is a naturally occurring antimicrobial peptide found in humans, specifically derived from the cathelicidin gene (CAMP). 

This small cationic peptide, comprising 37 amino acids, plays a pivotal role in the innate immune system, serving as a first-line defence against a wide range of pathogens, including bacteria, fungi, and viruses.

LL-37 is an amazing peptide often described like this: 

“LL-37, the sole human cathelicidin, draws particular attention because of its outstanding abilities. In addition to being a broad spectrum antibiotic, LL-37 has potent chemotactic and immunomodulatory properties.”

LL-37 is generated from the cathelicidin gene (CAMP), which is present in humans. This gene serves as the blueprint for the synthesis of LL-37, and its expression can be induced in response to various infectious challenges. The peptide is then synthesised and released as part of the body’s innate immune response.

LL-37 is not just any ordinary antimicrobial peptide; it possesses a multifaceted nature that allows it to effectively combat a wide spectrum of microorganisms. Its remarkable antimicrobial properties are made possible by its unique structural features, including its cationic charge and amphipathic structure.

One of the key features of LL-37 is its positive charge, resulting from the presence of positively charged amino acids, such as arginine and lysine, within its sequence. This positive charge enables LL-37 to interact with negatively charged components on the surface of microbial cells, making it an ideal candidate for disrupting the integrity of microbial membranes.

LL-37’s amphipathic structure is another crucial aspect of its functionality. This means that it has regions that are both hydrophobic (water-repellent) and hydrophilic (water-attracting). This structural duality allows LL-37 to insert itself into the lipid bilayer of microbial cell membranes. 

Once integrated, it can disrupt the membrane’s integrity by forming pores or causing structural damage, ultimately leading to cell death. The versatility of this structure allows LL-37 to effectively target various types of microorganisms.

LL-37 operates as an essential component of the innate immune system, which serves as the body’s first line of defence against invading pathogens. The peptide is rapidly mobilised when the body recognizes an infection. Its rapid response and broad-spectrum antimicrobial activity make LL-37 a critical player in preventing the spread of infections in their early stages.

How does it work?

LL-37’s mechanism of action is a captivating example of nature’s ingenuity in the realm of host defence peptides. Its antimicrobial activity primarily centres around its exceptional ability to disrupt the structural integrity of microbial membranes, a process that involves a precise interplay of its cationic and amphipathic characteristics.

Cationic Charge:

  • LL-37’s potent antimicrobial properties are, in part, a result of its cationic charge. 
  • This positive charge arises from the presence of positively charged amino acids, predominantly arginine and lysine, within its amino acid sequence. 
  • The cationic nature of LL-37 plays a pivotal role in its interaction with microbial membranes. As microbial membranes are typically negatively charged due to the presence of phospholipids and other components, LL-37 is attracted to these membranes by electrostatic forces.

Amphipathic Structure:

  • The amphipathic structure of LL-37 is another key aspect of its functionality. This structure means that it possesses regions with distinct hydrophobic (water-repellent) and hydrophilic (water-attracting) properties within its sequence. This duality allows LL-37 to insert itself into the lipid bilayer of microbial cell membranes, as it can interact both with the hydrophobic lipid tails and the hydrophilic phosphate head groups of the membrane.

Disruption of Microbial Membranes:

  • Once LL-37 has integrated into the lipid bilayer of a microbial membrane, it can exert its antimicrobial effects. The peptide can disrupt the integrity of the membrane through several mechanisms:
  • a. Formation of Pores: LL-37 can insert itself into the membrane and disrupt the lipid bilayer’s structural integrity, leading to the formation of pores or holes in the membrane. These pores can cause leakage of essential cellular components, ultimately leading to cell death.
  • b. Membrane Structural Damage: LL-37 can also disrupt the overall structure of the microbial membrane, making it more permeable. This disruption can interfere with the microorganism’s ability to maintain its cellular integrity and perform essential functions.

Versatility in Targeting Microorganisms:

  • LL-37’s adaptability and versatility are evident in its ability to adopt different conformations depending on the type of pathogen it encounters. This adaptability allows LL-37 to tailor its mode of attack to specific microbes, making it a formidable defender against a broad spectrum of pathogens.
What are the benefits?

LL-37’s versatile nature extends beyond its role as an antimicrobial peptide.

Research indicates that LL-37 plays a role in wound healing, tissue repair, and immune regulation. The peptide can modulate the inflammatory response and has been investigated in the context of autoimmune diseases and chronic inflammatory conditions. 

In a review by Kahlenberg et al. (2014), LL-37 was found to have immunomodulatory properties, suggesting potential therapeutic applications in autoimmune disorders.

Another review titled ‘Antimicrobial Peptide, LL-37 and its potential as an anti-HIV Agent highlights just one of the many benefits of LL-37, especially regarding HIV: 

“LL-37 has been studied for its anti-HIV activity and the limited data available suggest it can inhibit HIV infection in primary T cells as well as exert inhibitory effects on key HIV enzymes. Its immunomodulatory properties may both enhance and inhibit HIV replication. In addition, LL-37 has both 1) the ability to kill other sexually-transmitted pathogens and 2) spermicidal activity; thus, it is a good candidate for multipurpose prevention technology. Further investigation of its anti-HIV activity is warranted.”

Is it Antibacterial?

The antibacterial properties of LL-37 have been extensively studied, and research has consistently shown its effectiveness against a broad spectrum of bacterial species. 

LL-37 exhibits activity against gram-positive bacteria, including Staphylococcus aureus, as well as gram-negative bacteria like Escherichia coli and Pseudomonas aeruginosa.

A study exploring The Human Cathelicidin Antimicrobial Peptide LL-37 as a Potential Treatment for Polymicrobial Infected Wounds highlighted LL-37’s capacity to directly disrupt bacterial membranes, emphasising its role as an effective antimicrobial agent: 

“The single human cathelicidin peptide LL-37 has been shown to have antimicrobial and anti-biofilm activity against multiple Gram-positive and Gram-negative human pathogens, and have wound-healing effects on the host. The combination of the anti-biofilm effect and wound-healing properties of LL-37 may make it highly effective in resolving polymicrobial infected wounds when topically applied. Such a peptide or its derivatives could be a platform from which to develop new therapeutic strategies to treat biofilm-mediated infections of wounds.”

Is it Antifungal?


LL-37’s antimicrobial powers are not limited to bacteria; it extends to fungi as well. 

Fungal infections, such as candidiasis, can be challenging to treat, and LL-37 offers a promising solution. 

LL-37’s mechanism of action against fungi mirrors its approach to bacteria. The peptide’s cationic charge and amphipathic structure allow it to interact with the negatively charged components of fungal cell membranes. As it integrates into the lipid bilayer of the fungal membrane, it disrupts its structural integrity. This disruption can result in the formation of pores, leakage of cellular contents, and ultimately, cell death, similar to its action against bacteria.

Beyond direct membrane disruption, LL-37 may also impair the integrity of fungal cells in other ways. For example, it can interfere with the fungal cell’s ability to establish a successful infection by inhibiting adhesion to host cells or biofilm formation, a characteristic feature of Candida infections.

Is it Antiviral?

In recent years, LL-37’s antiviral properties have come to the forefront. Researchers have discovered that LL-37 can inhibit the replication of various viruses, including human immunodeficiency virus (HIV), influenza, and herpes simplex virus. 

Its mechanism of action against viruses is multifaceted, involving direct virucidal activity, interference with viral entry into host cells, and modulation of the host immune response.

LL-37’s antiviral potential has generated significant interest in exploring its therapeutic applications in combating viral infections.

A study by Bergman et al. (2007) indicated that LL-37 can effectively reduce viral replication and has potential applications in the fight against viral infections stating:  

“We have evaluated the capacity of LL-37 to inhibit HIV-1 infection in vitro. Here we demonstrate that LL-37 inhibits HIV-1 replication in PBMC, including primary CD4+ T cells. This inhibition was readily reproduced using various HIV-1 isolates without detectable changes in the target cell expression of HIV-1 chemokine receptors. Accordingly, the HIV-1 inhibitory effect was shown to be independent of FPRL-1 signalling. Given the epithelial expression of LL-37, it may contribute to the local protection against HIV-1 infection.”

Dosage and how to take it

After delving into our informative article on LL-37, you may be eager to explore its potential, especially if you’re new to Peptide Therapy.

The safety and potential side effects of LL-37, like any compound, can vary based on factors such as the dosage, individual characteristics, and interactions with other medications or medical conditions.

To obtain LL-37 or any of our peptides, you can schedule a consultation with our Integrative and Functional Medicine specialist, Jessica. With her extensive experience in Peptide Therapy, she will guide you through your journey.

These consultations are available for international clients, and are not subject to the UK only.

Diverse Range of Biological Functions

Why Nūūtro is your go-to for Peptide Therapy

In contrast to the myriad sources that might leave you puzzled or uncertain, our unwavering commitment at Nūūtro sets us apart. We are dedicated to providing you with the gold-standard in quality, safety, and integrity when it comes to LL-37.

Here at Nūūtro, you can have full confidence in our team and products, driven by an unwavering pursuit of well-being. We are genuinely excited to be a part of your transformation. We’re here to support you every step of the way.

Our steadfast commitment to your health is evident in every aspect of what we do:

  • We only source our peptides from accredited USA-labs that use the purest ingredients.
  • Jessica has personally met the owner and COO of our peptide supplier, we only do business with integrity.
  • Our peptides are rigorously third-party tested.
  • We work with you to discuss other issues such as gut inflammation and hormonal disbalance prior to ensuring the peptides work to their full efficacy. 

Enjoy your journey here with Nūūtro, where we can assist you in achieving your wellness goals. 

To learn more about our Peptide Therapy programmes click here.

Enquire Today

To learn more about our Peptide Therapy, please request an appointment at info@nuutro.co.uk