GLP: Good Laboratory Practice for Cannabis

Good Laboratory Practice (GLP) for Cannabis Testing Laboratories

Good Laboratory Practice (GLP) is a vital quality framework applied specifically to laboratory testing in the medical cannabis industry. It ensures the reliability, consistency, and accuracy of results, which are essential for meeting regulatory requirements, ensuring product safety, and building trust among patients, healthcare providers, and consumers.

GLP standards primarily focus on independent third-party testing laboratories that verify the quality and safety of cannabis products before they are released to the market. However, in-house processing labs that perform their own analytical testing for internal quality control can also benefit from adhering to GLP principles, ensuring that their testing methods meet the same stringent requirements as external labs. This not only improves product quality but also helps meet regulatory and compliance benchmarks.

The Importance of GLP in Cannabis Testing

In the rapidly evolving cannabis industry, particularly within the medical cannabis space, analytic testing is essential to validate the safety, potency, and purity of products. While the scientific techniques used for cannabis testing—such as HPLC (High-Performance Liquid Chromatography), GC (Gas Chromatography), and microbial assays—are well understood, standardization is still a challenge, even in mature markets.

Testing is essential for verifying cannabinoid content, identifying contaminants such as pesticides, heavy metals, and residual solvents, and ensuring microbial safety. GLP-compliant laboratories play a key role in ensuring these tests are accurate and reliable. In addition, any laboratory performing testing, whether in-house or independent, must use validated methods, reference standards, and trained personnel to meet regulatory guidelines and ensure product integrity.

Internal Testing vs. Third-Party Testing

While third-party testing is often required for regulatory compliance, having an in-house GLP-compliant testing program can offer significant advantages for cannabis and hemp processors. By incorporating GLP into their in-house labs, processors can ensure faster turnaround times for quality checks, improve the consistency of their processes, and make real-time adjustments based on validated data. This internal testing provides an additional layer of quality assurance, complementing external validation by third-party labs.

It is critical, however, that both in-house and third-party labs adhere to GLP standards. Without rigorous GLP implementation, testing data could be unreliable, leading to product recalls, non-compliance with regulations, or worse—unsafe products reaching patients or consumers.

ISO 17025: The Benchmark for Cannabis Testing

GLP-compliant laboratories should operate in accordance with ISO 17025 standards. ISO 17025 specifies the general requirements for the competence of testing and calibration laboratories, ensuring that laboratories consistently produce valid results. This international standard covers the testing, calibration, and sampling processes using both standard and laboratory-developed methods. Cannabis testing laboratories following ISO 17025 protocols provide the assurance that their testing is both accurate and consistent, with proper calibration and documentation.

ISO 17025 is particularly important in cannabis testing for validating critical parameters such as:

Cannabinoid potency (THC, CBD, CBG, etc.)
Terpene profiles
Microbial contamination (yeasts, molds, and bacteria)
Pesticide residues
Heavy metals
Residual solvents (from extraction processes)

For companies working with hemp, these tests are crucial to ensure that products comply with legal THC limits (<0.3%) and are free from harmful contaminants.

The Role of Third-Party Cannabis Testing Labs

While in-house testing can serve as the first line of quality control, third-party testing provides independent verification that ensures regulatory compliance. By working with external laboratories certified under GLP and ISO 17025 standards, cannabis processors can enhance their credibility and demonstrate to regulators, consumers, and business partners that their products meet the required safety and quality standards.

Third-party testing offers:

Independent validation of product safety and potency
Proof of compliance with state, national, and international regulations
Certificates of Analysis (CoAs) that can be shared with distributors, retailers, and end-users

Rhizo Sciences works closely with accredited third-party laboratories to ensure that every product we process or distribute adheres to the highest quality standards. We support our partners in choosing the right laboratories, implementing quality testing programs, and maintaining compliance with evolving regulations.

GLP Implementation: Rhizo Sciences’ Expertise

Rhizo Sciences is a trusted partner for cannabis and hemp companies looking to implement GLP within their laboratories or partner with third-party GLP-compliant testing labs. Our consulting services include helping businesses develop robust testing and quality control programs that meet all regulatory and market requirements. Whether you are establishing an in-house lab or seeking external verification, we ensure you have the tools and expertise to meet the highest standards.

Why Choosing a GLP-Compliant Vendor Matters

When selecting a cannabis or hemp vendor, it’s critical to choose one that adheres to GLP and ISO standards. This guarantees that the products have been rigorously tested for quality, safety, and regulatory compliance. By choosing GLP-compliant vendors, you protect your brand, your customers, and your reputation in the market.

At Hempex, we are committed to quality at every step of the process. Our hemp-derived products, including CBD oil, CBD distillate, and CBD isolate, are thoroughly tested for cannabinoid content, contaminants, and overall purity, ensuring consistency and safety in every batch.

Hempex Hemp Quality Statement

Although hemp is distinct from cannabis in terms of THC content, it remains part of the cannabis species and is subject to similar regulatory scrutiny. Hempex follows the same rigorous GLP and GMP standards as medical cannabis, ensuring the safety, quality, and consistency of all our products.

Our Commitment to Quality Hemp Products:

All of our hemp-derived products are thoroughly tested for cannabinoid profiles, contaminants, and purity in GLP-compliant, ISO 17025-certified laboratories.
We provide full transparency through Certificates of Analysis (CoAs) that accompany every batch of product, including CBD oil, CBD distillate, and CBD isolate.
We adhere to stringent quality controls to ensure consistency across all products, protecting both consumers and businesses from substandard materials.
We maintain sustainable and environmentally responsible practices throughout the supply chain.

Partner with Hempex for GLP-compliant hemp products that meet the highest standards of quality and safety. Contact us today to learn more about how we can support your business with safe, reliable, and compliant hemp products.