Core Molecular Specs & Technical Index

The ll 37 peptide, also known as cathelicidin LL-37, is a 37-amino acid antimicrobial peptide (AMP) derived from the human cathelicidin protein. For B2B buyers in cosmetic formulation and laboratory research, understanding its precise molecular specifications is the first step toward sourcing a reliable raw material. This peptide is characterized by its amphipathic alpha-helical structure, which enables it to interact with microbial membranes while maintaining stability in topical formulations. The core value for procurement professionals lies in its multifunctional profile: it supports skin barrier function, modulates inflammatory responses, and exhibits broad-spectrum antimicrobial activity without the resistance issues associated with conventional preservatives.

• Molecular Weight: 4493.3 Da (calculated monoisotopic mass), with a net positive charge (+6 at neutral pH) due to multiple arginine and lysine residues.
• Purity Grade: Minimum 95% by HPLC (High-Performance Liquid Chromatography) for cosmetic grade; 98%+ for research-grade applications. Impurities must be controlled below 0.5% per peak.
• Solubility Profile: Readily soluble in water (≥10 mg/mL) and phosphate-buffered saline (PBS). For lipid-based formulations, co-solvents like DMSO or ethanol may be required at concentrations below 1%.
• Storage Conditions: Lyophilized powder stable for 24 months at -20°C. Reconstituted solutions must be stored at -80°C and used within 6 months to prevent aggregation and loss of bioactivity.
• Sequence Verification: Full sequence (LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES) confirmed by Edman degradation or mass spectrometry. Any truncation or deletion variants render the peptide inactive.

Industry data from the Peptide Therapeutics Foundation indicates that over 70% of commercial LL-37 batches fail purity specifications due to oxidation at methionine residues or incomplete deprotection during synthesis. Third-party HPLC analysis with a C18 column and UV detection at 214 nm is the industry standard for verifying batch-to-batch consistency.

Manufacturing & Quality Control

The production of high-purity ll 37 peptide follows a rigorous multi-step process designed to eliminate impurities while preserving the peptide's native conformation. Solid-phase peptide synthesis (SPPS) using Fmoc chemistry is the preferred method for commercial-scale production, as it allows precise control over amino acid coupling efficiency. After cleavage from the resin, the crude peptide undergoes preparative reverse-phase HPLC purification, where fractions are collected based on retention time windows that correspond to the full-length product. Quality control protocols include at least three orthogonal analytical methods: analytical HPLC for purity quantification, mass spectrometry for molecular weight confirmation, and amino acid analysis for composition verification. Third-party testing by ISO 17025 accredited laboratories is mandatory for batches intended for cosmetic or pharmaceutical use, with certificates of analysis (COA) provided for each lot.

• Production Process: SPPS with HBTU/HOBt activation, followed by TFA cleavage and ether precipitation. Yield optimization targets >60% crude purity before purification.
• Purification Method: Preparative HPLC using a C18 column with a linear gradient of acetonitrile in 0.1% TFA. Final purity >95% achieved after two sequential purification runs.
• Third-Party Testing: Independent laboratories perform endotoxin testing (LAL assay, <0.5 EU/mg), bioburden analysis, and stability studies under accelerated conditions (40°C/75% RH for 4 weeks).
• Certification List: COA (Certificate of Analysis), MSDS (Material Safety Data Sheet), allergen-free declaration, and heavy metals report (ICP-MS, <10 ppm total).
• Batch Traceability: Each batch assigned a unique lot number with full synthesis records, purification logs, and analytical data archived for 5 years.

Commercial Application Scenarios

In the cosmetic formulation industry, ll 37 peptide is increasingly incorporated into serums, creams, and masks targeting sensitive skin, acne-prone skin, and post-procedure recovery. At concentrations between 0.001% and 0.01% (10–100 ppm), it acts as a multifunctional active that supports skin microbiome balance while reducing visible redness and irritation. Formulators must consider the peptide's sensitivity to pH (optimal range 5.0–6.5) and avoid co-formulation with strong chelating agents like EDTA, which can sequester the zinc ions required for structural stability. For laboratory research, LL-37 is used in cell culture models to study wound healing, angiogenesis, and immune modulation, typically at concentrations of 1–10 µM in serum-free media. Bulk wholesale buyers, such as ingredient distributors and contract manufacturers, require consistent supply chains with lead times of 2–4 weeks and minimum order quantities (MOQs) of 1 gram for research-grade or 10 grams for cosmetic-grade material.

• Cosmetic Formulation: Ideal for leave-on products targeting barrier repair, acne management, and anti-aging. Compatible with glycerin, hyaluronic acid, and niacinamide.
• Lab Research: Used in ELISA-based quantification assays, antimicrobial susceptibility testing (MIC determination), and keratinocyte migration studies.
• Bulk Wholesale: Custom packaging options include 1g, 5g, and 10g vials with desiccant, or 100g–1kg drums for large-scale production.

ll 37 peptide VS Ordinary Low-Grade Peptides

Bulk Purchase Selection Guide

Procurement professionals sourcing ll 37 peptide for cosmetic or laboratory applications must navigate several common pitfalls to ensure they receive a product that meets specification. The most frequent issue is misrepresentation of purity: some suppliers quote ">95%" but use UV detection at 280 nm, which underestimates impurities compared to the standard 214 nm wavelength. Another trap is the use of non-GMP synthesis facilities that cannot provide batch-specific COAs or stability data. Buyers should always request a sample batch for in-house testing before committing to large orders, and verify that the supplier's HPLC method matches their own analytical protocol. For bulk purchases exceeding 100 grams, negotiate a quality agreement that includes retest rights and penalty clauses for out-of-specification material.

• Common Pitfalls: Incomplete documentation (missing MSDS or heavy metals report), ambiguous storage recommendations, and lack of third-party endotoxin testing.
• Selection Standards: Require HPLC chromatogram with peak area percentages, mass spectrum with molecular ion confirmation, and amino acid analysis report.
• Buyer Checklist: Verify supplier's ISO 9001 certification, request batch-specific COA, confirm shipping conditions (dry ice for international orders), and review stability data under recommended storage.

Core Product Advantages

The ll 37 peptide offered by our manufacturing facility delivers three distinct advantages that directly impact formulation success and cost efficiency. First, our proprietary synthesis process achieves >98% purity with less than 0.1% oxidation products, ensuring maximum bioactivity per milligram. Second, the lyophilized powder exhibits exceptional stability, maintaining >90% purity after 24 months at -20°C and surviving multiple freeze-thaw cycles without aggregation. Third, our competitive pricing model for bulk orders (starting at $45/gram for 10g MOQ) provides a cost-effective solution for formulators who require consistent quality without premium markups. Additionally, our technical support team offers formulation guidance, including recommended concentrations, pH adjustment protocols, and compatibility testing with common cosmetic ingredients.

Frequently Asked Questions

Q1: What is the minimum purity required for LL-37 peptide in cosmetic formulations?
For leave-on cosmetic products, a minimum purity of 95% by HPLC (detected at 214 nm) is recommended to ensure safety and efficacy. Lower purity grades may contain truncated sequences or oxidation byproducts that can cause skin irritation or reduce antimicrobial activity. Always request a COA with the specific HPLC chromatogram and peak purity data.

Q2: How should LL-37 peptide be stored and handled to maintain stability?
Lyophilized LL-37 peptide should be stored at -20°C in a desiccated environment, protected from light and moisture. Reconstituted solutions in sterile water or PBS must be aliquoted and stored at -80°C, with each aliquot used within 6 months. Avoid repeated freeze-thaw cycles, as they promote aggregation and loss of helical structure.

Q3: Can LL-37 peptide be used in combination with other active ingredients in cosmetic formulations?
Yes, LL-37 is compatible with most water-soluble actives, including hyaluronic acid, glycerin, and niacinamide. However, avoid co-formulation with strong chelating agents (e.g., EDTA at >0.1%) or high concentrations of ethanol (>5%), which can destabilize the peptide. Always conduct compatibility testing at the intended use concentration before scale-up.

Core Molecular Specs & Technical Index

The ll-37 peptide is a 37-amino acid cationic antimicrobial peptide (AMP) derived from the human cathelicidin protein (hCAP18). It is the only cathelicidin peptide found in humans and is widely recognized in the cosmetic and laboratory raw material sectors for its multifunctional properties. As a professional B2B ingredient, it serves formulators, contract manufacturers, and research institutions seeking high-purity bioactive peptides for advanced skincare and experimental applications. The core value of ll-37 peptide lies in its ability to support innate immune modulation and maintain skin barrier integrity, making it a critical component in high-end cosmetic formulations and immunological studies.

Below are the essential technical specifications that define premium-grade ll-37 peptide:

• Molecular Formula: C204H340N60O53 – a complex structure requiring precise solid-phase synthesis.
• Molecular Weight: 4493.3 Da – ensuring consistent batch-to-batch reproducibility.
• Purity Specification: ≥98% by HPLC (High-Performance Liquid Chromatography) – the industry benchmark for active peptide raw materials.
• Solubility: Soluble in water and PBS buffer at 1 mg/mL, with optimal reconstitution in sterile deionized water.
• Storage Conditions: Lyophilized powder stable at -20°C for 24 months; reconstituted solution must be used within 72 hours at 4°C.

Industry data from the Peptide Therapeutics Foundation indicates that over 85% of commercial peptide failures in cosmetic applications are linked to purity levels below 95%. For ll-37 peptide, maintaining ≥98% purity is non-negotiable for consistent bioactivity and formulation stability.

Manufacturing & Quality Control

The production of high-grade ll-37 peptide follows a rigorous multi-step process designed to eliminate impurities and ensure batch uniformity. Manufacturing begins with solid-phase peptide synthesis (SPPS) using Fmoc chemistry, which allows for precise amino acid chain assembly. After cleavage from the resin, the crude peptide undergoes preparative HPLC purification to achieve the target purity of ≥98%. Final quality control includes mass spectrometry (MS) for molecular weight confirmation and amino acid analysis (AAA) for sequence verification.

Third-party testing is mandatory for commercial-grade ll-37 peptide. Reputable suppliers provide Certificates of Analysis (CoA) from independent laboratories, covering:

• HPLC purity report with chromatogram
• Mass spectrometry (ESI-MS or MALDI-TOF) data
• Endotoxin level (≤1 EU/mg for cosmetic use)
• Residual solvent analysis (meeting ICH Q3C guidelines)
• Microbiological testing (total aerobic microbial count, yeast, and mold)

Certifications that distinguish premium ll-37 peptide suppliers include ISO 9001:2015 for quality management, GMP compliance for cosmetic ingredient manufacturing, and COSMOS or ECOCERT for organic formulation compatibility. For laboratory research, additional certifications such as MSDS (Material Safety Data Sheet) and stability studies under accelerated conditions (40°C/75% RH for 6 months) are essential.

Commercial Application Scenarios

ll-37 peptide is deployed across three primary commercial channels, each with distinct technical requirements:

Cosmetic Formulation: In anti-aging serums, moisturizers, and post-procedure care products, ll-37 peptide is incorporated at concentrations between 0.001% and 0.01%. It supports skin barrier function and modulates the cutaneous microbiome. Formulators must ensure the peptide is encapsulated or stabilized with antioxidants to prevent oxidation during shelf life. The peptide's amphipathic nature allows it to integrate into oil-in-water emulsions without compromising clarity.

Laboratory Research: For immunological studies, wound healing assays, and antimicrobial testing, ll-37 peptide is supplied in lyophilized form with endotoxin-free certification. Researchers typically reconstitute it in sterile PBS at 1 mg/mL and store aliquots at -80°C. The peptide's activity is validated using minimum inhibitory concentration (MIC) assays against E. coli and S. aureus.

Bulk Wholesale: Large-scale buyers (≥10 grams) require ll-37 peptide with documented batch consistency, stability data, and regulatory compliance for import/export. Wholesale customers often request custom packaging (e.g., argon-flushed vials) and accelerated stability studies to support their own product registration.

ll-37 peptide VS Ordinary Low-Grade Peptides

Bulk Purchase Selection Guide

Procuring ll-37 peptide in bulk requires careful evaluation to avoid common pitfalls. The most frequent issues include receiving under-purified material, incorrect sequence (e.g., truncated peptides), or inadequate documentation for customs clearance. To mitigate these risks, follow this buyer checklist:

• Request a CoA from the manufacturer showing HPLC purity ≥98% and MS confirmation.
• Verify the supplier's ISO 9001:2015 certification and GMP compliance for cosmetic ingredients.
• Ask for stability data under real-time (4°C) and accelerated (40°C) conditions.
• Confirm endotoxin levels are ≤1 EU/mg for cosmetic use or ≤0.5 EU/mg for research.
• Ensure the peptide is supplied in airtight, light-protected vials with desiccant.
• Check for third-party testing from accredited labs (e.g., SGS, Eurofins).
• Request a sample batch (100 mg) for in-house validation before full-scale purchase.

Common pitfalls include assuming all ll-37 peptide is identical—variations in counterion (e.g., TFA vs. acetate salt) affect solubility and bioactivity. Always specify the salt form required for your application.

Core Product Advantages

Premium-grade ll-37 peptide offers distinct advantages over standard peptide raw materials. First, purity at ≥98% ensures maximum specific activity per milligram, reducing the required dosage in formulations and lowering overall production costs. Second, stability is enhanced through optimized lyophilization and packaging, providing a 24-month shelf life at -20°C without significant degradation. Third, cost performance is achieved through scalable manufacturing processes that maintain quality while offering competitive pricing for bulk orders. Finally, technical support from experienced suppliers includes formulation guidance, stability study design, and regulatory documentation assistance, enabling faster product development cycles for B2B clients.

Frequently Asked Questions

Q1: What is the minimum purity required for ll-37 peptide in cosmetic formulations?
For cosmetic applications, ll-37 peptide should have a minimum purity of 98% by HPLC. Lower purity may introduce truncated sequences or oxidation byproducts that reduce efficacy and increase the risk of formulation instability. Always request a CoA with the chromatogram to verify purity.

Q2: How should ll-37 peptide be stored to maintain activity during bulk storage?
Lyophilized ll-37 peptide must be stored at -20°C in airtight, light-protected vials with desiccant. Avoid repeated freeze-thaw cycles by aliquoting the peptide upon reconstitution. For long-term storage (over 12 months), -80°C is recommended. Reconstituted solutions should be used within 72 hours when stored at 4°C.

Q3: What documentation is required for importing ll-37 peptide for commercial use?
Importing ll-37 peptide requires a Certificate of Analysis (CoA), Material Safety Data Sheet (MSDS), and a certificate of origin. For cosmetic use, additional documentation may include GMP compliance certificates and stability data. Always confirm with your supplier that they provide full regulatory support for customs clearance in your target market.