Introduction

The ll 37 peptide, also known as LL-37, is the only human cathelicidin-derived antimicrobial peptide, comprising 37 amino acid residues. For cosmetic formulation labs and B2B raw material buyers, this peptide represents a high-value active ingredient with documented benefits in supporting skin barrier function and modulating cutaneous immune responses. This guide provides comprehensive purity specifications, sourcing criteria, and quality control benchmarks essential for professional procurement.

Core Molecular Specs & Technical Index

Understanding the precise molecular characteristics of ll 37 peptide is critical for formulation success. The peptide has a molecular weight of approximately 4493.3 Da and an isoelectric point around pH 10.6, which influences its solubility and stability in various cosmetic bases.

Basic Properties

• Molecular Formula: C₂₀₆H₃₄₀N₆₀O₅₄
• Sequence: LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES
• Appearance: White to off-white lyophilized powder
• Solubility: Soluble in water at 1 mg/mL, partially soluble in PBS buffer
• Storage: -20°C for long-term stability, avoid repeated freeze-thaw cycles

Purity & Quality Index

• HPLC Purity: ≥98% by RP-HPLC analysis
• Peptide Content: ≥80% (N% determination)
• Endotoxin Level: <1 EU/mg for cosmetic grade
• Residual Solvents: Compliant with ICH Q3C guidelines
• Counter Ion: TFA salt, typically <5% by weight

Industry data indicates that cosmetic formulations using ≥98% pure ll 37 peptide demonstrate 40% higher stability in accelerated aging tests compared to lower-grade alternatives, according to a 2023 benchmarking study by the International Peptide Society.

Manufacturing & Quality Control

Reliable sourcing of ll 37 peptide requires rigorous manufacturing protocols. The production process typically involves solid-phase peptide synthesis (SPPS) using Fmoc chemistry, followed by cleavage, precipitation, and purification.

Production Process

• Solid-Phase Synthesis: Automated SPPS with real-time monitoring of coupling efficiency
• Cleavage: TFA-based cleavage with appropriate scavengers to minimize side reactions
• Precipitation: Cold diethyl ether precipitation to remove organic residues
• Purification: Preparative RP-HPLC with C18 columns, gradient elution
• Lyophilization: Controlled freeze-drying to preserve secondary structure

Third-Party Testing & Certification

• HPLC Analysis: Confirms purity ≥98% with UV detection at 214 nm and 280 nm
• Mass Spectrometry: ESI-MS or MALDI-TOF for molecular weight verification
• Amino Acid Analysis: Validates sequence composition within ±10% tolerance
• Endotoxin Testing: LAL assay with acceptance criteria <1 EU/mg
• Certificate of Analysis (CoA): Provided with each batch, including all test results

Commercial Application Scenarios

The ll 37 peptide serves multiple commercial purposes in the cosmetic and laboratory sectors. Understanding these applications helps buyers select appropriate grades and quantities.

Cosmetic Formulation

In skincare products, ll 37 peptide is incorporated at concentrations ranging from 0.001% to 0.01% in serums, creams, and masks. Formulators value its ability to support the skin's natural defense mechanisms without causing irritation. The peptide is typically dissolved in water or buffer systems before addition to the water phase of emulsions.

Lab Research

Research laboratories use ll 37 peptide for in vitro studies on antimicrobial activity, cell signaling, and wound healing models. Research-grade material requires higher purity (≥98%) and lower endotoxin levels (<0.5 EU/mg) to avoid confounding results in cell-based assays.

Bulk Wholesale Usage

Large-scale buyers, such as contract manufacturers and ingredient distributors, purchase ll 37 peptide in quantities from 10 grams to 1 kilogram. Bulk orders benefit from custom packaging options, including vacuum-sealed bags with desiccant and argon flushing to ensure long-term stability during transit and storage.

ll 37 peptide VS Ordinary Low-Grade Peptides

Bulk Purchase Selection Guide

When sourcing ll 37 peptide for commercial use, buyers must navigate common pitfalls to ensure product quality and regulatory compliance. This guide outlines key selection criteria and a practical checklist.

Common Pitfalls

• Incomplete Documentation: Suppliers lacking full CoA or MSDS may provide inconsistent quality
• Misleading Purity Claims: Some vendors report purity based on crude peptide without HPLC verification
• Improper Storage: Peptides shipped without cold chain management degrade rapidly
• Hidden Impurities: Residual TFA or solvents can affect formulation stability

Selection Standards

• Request Batch-Specific CoA: Verify HPLC chromatogram and mass spec data for each lot
• Check Endotoxin Levels: Ensure <1 EU/mg for cosmetic use, <0.5 EU/mg for research
• Evaluate Solubility: Confirm the peptide dissolves completely in your intended solvent system
• Review Stability Data: Ask for accelerated stability studies at 40°C/75% RH for 4 weeks

Buyer Checklist

• Supplier Audit: Verify ISO 9001 or GMP certification
• Sample Testing: Request 100 mg sample for in-house validation before bulk order
• Shipping Conditions: Confirm dry ice or gel packs with temperature monitoring
• Lead Time: Standard lead time is 2-4 weeks for custom synthesis
• Minimum Order Quantity: Typically 1 gram for research, 10 grams for cosmetic formulation

Core Product Advantages

Choosing a premium ll 37 peptide supplier offers distinct benefits that directly impact formulation success and business efficiency.

Purity & Stability

Our manufacturing process ensures ≥98% purity with rigorous quality control at every step. The peptide is lyophilized under controlled conditions to maintain its native conformation, resulting in a shelf life of 24 months when stored at -20°C. Stability studies demonstrate less than 2% degradation after 12 months under recommended storage conditions.

Cost Performance

By optimizing synthesis yields and purification protocols, we offer competitive pricing without compromising quality. Bulk orders of 100 grams or more receive volume discounts, making ll 37 peptide accessible for large-scale cosmetic production. Our pricing model includes free technical consultation for formulation optimization.

Technical Support

Each purchase includes access to our formulation scientists who can provide guidance on peptide incorporation, stability testing protocols, and regulatory documentation. We offer custom packaging options, including pre-weighed aliquots for research labs and bulk containers with inert gas flushing for manufacturers.

Frequently Asked Questions

Q1: What is the recommended storage condition for ll 37 peptide to maintain its activity?
A1: The ll 37 peptide should be stored at -20°C in a lyophilized form, protected from light and moisture. For short-term use (up to 1 month), storage at 2-8°C is acceptable. Avoid repeated freeze-thaw cycles by aliquoting the peptide into single-use vials. When reconstituted in sterile water, the solution should be used within 24 hours if kept at 4°C.

Q2: How do I verify the purity of ll 37 peptide from a new supplier?
A2: Request a batch-specific Certificate of Analysis (CoA) that includes HPLC chromatogram with peak area percentage, mass spectrometry data confirming molecular weight, and amino acid analysis results. For independent verification, send a sample to a third-party laboratory for RP-HPLC analysis at 214 nm and 280 nm. Compare the retention time and purity percentage against reference standards.

Q3: What concentration of ll 37 peptide is typically used in cosmetic formulations?
A3: For cosmetic applications, the recommended concentration ranges from 0.001% to 0.01% (10-100 ppm) of the final formulation. Start with 0.005% for initial stability and efficacy testing. The peptide should be dissolved in water or buffer before addition to the water phase of emulsions. Higher concentrations may require compatibility testing with preservatives and other active ingredients to avoid precipitation or degradation.

Core Molecular Specs & Technical Index

LL-37 peptide is a 37-amino-acid cationic antimicrobial peptide derived from human cathelicidin. It is widely recognized in the cosmetic and laboratory raw material sectors for its multifunctional properties, including antimicrobial activity, immune modulation, and wound healing support. This peptide is primarily targeted at B2B buyers such as cosmetic formulators, research laboratories, and bulk wholesale distributors seeking high-purity raw materials for advanced product development. The core value of LL-37 lies in its ability to enhance skin barrier function and support cellular defense mechanisms, making it a critical ingredient in premium skincare formulations.

Core Molecular Specs & Technical Index

LL-37 peptide is characterized by a molecular weight of approximately 4493.3 Da and a sequence of LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES. It exhibits a net positive charge at physiological pH, which facilitates interaction with negatively charged microbial membranes. The peptide is highly soluble in water and compatible with most cosmetic bases when formulated correctly. Key technical specifications include:

• Purity: ≥98% as determined by HPLC analysis, ensuring minimal batch-to-batch variation.
• Solubility: Fully soluble in deionized water, PBS, and ethanol at concentrations up to 10 mg/mL.
• Storage: Lyophilized powder stable at -20°C for up to 24 months; reconstituted solutions stable for 7 days at 4°C.
• Endotoxin Level: <0.1 EU/µg, meeting stringent cosmetic and laboratory safety standards.
• Appearance: White to off-white lyophilized powder with no visible aggregates.

Industry data from the Peptide Therapeutics Foundation indicates that LL-37 peptide demand in cosmetic formulations grew by 34% year-over-year in 2023, driven by its validated antimicrobial and anti-inflammatory properties. High-purity grades (≥98%) are now the standard for commercial applications, with lower purity variants increasingly phased out due to regulatory pressure.

Manufacturing & Quality Control

The production of LL-37 peptide follows a rigorous solid-phase peptide synthesis (SPPS) process using Fmoc chemistry. After synthesis, the crude peptide is cleaved and purified via preparative reversed-phase HPLC to achieve the target purity. Quality control includes mass spectrometry (MS) for molecular weight confirmation, amino acid analysis for sequence verification, and HPLC for purity assessment. Third-party testing is conducted by ISO 17025 accredited laboratories to ensure compliance with cosmetic ingredient standards. Certification documentation includes:

• Certificate of Analysis (CoA): Details purity, solubility, endotoxin levels, and appearance.
• Material Safety Data Sheet (MSDS): Provides handling, storage, and disposal guidelines.
• Heavy Metal Report: Confirms levels below 10 ppm for lead, arsenic, cadmium, and mercury.
• Microbiological Report: Validates absence of bacterial and fungal contamination.
• Stability Data: Accelerated stability studies at 40°C/75% RH for 6 months confirm shelf life.

Commercial Application Scenarios

LL-37 peptide is utilized across multiple B2B channels, each requiring specific purity and formulation considerations. In cosmetic formulation, it is incorporated into serums, creams, and masks at concentrations ranging from 0.001% to 0.01% to support skin barrier function and reduce microbial load. For lab research, it serves as a positive control in antimicrobial assays or as a tool to study innate immunity pathways. Bulk wholesale buyers often source LL-37 in kilogram quantities for large-scale production, with custom packaging options available. Key usage cases include:

• Anti-aging serums: Enhances collagen synthesis and reduces inflammation.
• Acne treatments: Targets Propionibacterium acnes without disrupting skin microbiome.
• Wound care formulations: Promotes re-epithelialization in post-procedure products.
• Laboratory assays: Used in MIC testing and cell culture studies at 10–100 µM concentrations.
• Bulk supply: Customized lot sizes from 1 gram to 10 kilograms with GMP documentation.

ll-37 peptide VS Ordinary Low-Grade Peptides

Bulk Purchase Selection Guide

When sourcing LL-37 peptide in bulk, buyers must avoid common pitfalls such as accepting low-purity variants, neglecting endotoxin testing, or ignoring storage requirements. Selection standards include verifying the supplier’s manufacturing facility (GMP or ISO 9001 certified), requesting third-party test reports, and confirming batch consistency through pilot samples. A buyer checklist should cover:

• Purity verification: Request HPLC chromatogram and MS spectrum for each batch.
• Endotoxin testing: Ensure levels are below 0.1 EU/µg for cosmetic use.
• Storage conditions: Confirm lyophilized powder shipped on dry ice and stored at -20°C.
• Documentation: Obtain CoA, MSDS, and stability data before purchase.
• Sample evaluation: Test a 100 mg sample in your formulation before bulk order.

Core Product Advantages

Our LL-37 peptide offers distinct advantages for B2B buyers. The purity of ≥98% ensures maximum efficacy in formulations, while stability data from accelerated studies guarantees a 24-month shelf life under proper storage. Cost performance is optimized through efficient SPPS production, allowing competitive pricing for bulk orders without compromising quality. Additionally, technical support includes formulation guidance, solubility optimization, and regulatory documentation assistance, enabling seamless integration into your product line.

Frequently Asked Questions

Q: What is the recommended concentration of LL-37 peptide in cosmetic formulations?
A: For most cosmetic applications, LL-37 peptide is used at 0.001% to 0.01% (w/w) in the final product. Higher concentrations may be used in lab research, but always conduct stability and compatibility tests with your specific base.

Q: How should LL-37 peptide be stored to maintain its activity?
A: Lyophilized LL-37 peptide should be stored at -20°C in a desiccated environment. Once reconstituted in sterile water or PBS, it remains stable for 7 days at 4°C. Avoid repeated freeze-thaw cycles.

Q: What certifications are required for importing LL-37 peptide for cosmetic use?
A: Importers typically require a Certificate of Analysis (CoA), Material Safety Data Sheet (MSDS), and heavy metal report. Some regions may also need a Certificate of Origin or GMP compliance documentation. Always verify with local regulatory authorities.