How to Read a Cannabis Certificate of Analysis (COA)

Medical Disclaimer

Homestead Health is a licensed medical cannabis processor and does not make medical claims. The information provided is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. All persons must speak to a licensed, state-registered physician to be diagnosed and/or recommended medical cannabis for a qualifying medical condition in the state of alabama.

By Homestead Health – Alabama’s Leader in Pharmaceutical-Grade Medical Cannabis Processing

Overview

Educational resource. Last reviewed: June 2026. This article explains how to interpret a laboratory certificate of analysis. It is for general education only and is not medical advice. For verified results on a specific product, always refer to the certificate of analysis that accompanies your individual package.

In a tightly regulated medical cannabis program, the certificate of analysis – usually abbreviated COA – is the single most important document a patient can learn to read. It is the independent laboratory record that confirms what is, and is not, in a product. A COA is where the abstract promise of “tested and compliant” becomes concrete, verifiable data. Yet most patients have never been shown how to interpret one, and the documents can look intimidating: dense tables of compounds, abbreviations, and numbers with “less-than” signs scattered throughout.

This guide demystifies the COA. It walks through each section a patient is likely to encounter, explains the analytical terms that cause the most confusion, and shows how to match a published COA to the specific package in hand. The goal is practical literacy – so that “third-party tested” becomes something you can independently confirm rather than something you have to take on faith.

What a Certificate of Analysis Is

A certificate of analysis is a formal report issued by an accredited, independent testing laboratory that documents the results of the analyses performed on a sample of a product. In Alabama’s program, finished medical cannabis products are analyzed by a licensed state testing laboratory that operates separately from the companies that grow and manufacture the product [1]. This separation is deliberate: the laboratory has no commercial stake in the result, which is what gives the COA its credibility.

Alabama’s licensed testing laboratories include Green Health Laboratories, which operates under the state’s medical cannabis testing laboratory license [2]. A laboratory of this type publishes results that “relate only to the items tested” – a standard analytical disclaimer meaning the data describes the specific sample submitted, not every package ever produced. That single sentence is why batch-level verification matters, a theme we return to throughout this guide.

The Identity Header: Knowing Exactly What Was Tested

Every COA opens with an identification block. This is the part patients most often skip, but it is what ties the data to a specific batch. Typical fields include:

• Sample ID – a unique identifier assigned to the tested sample.
• Product name and type – for example, an ingestible gel cube, an ingestible tincture, or a topical lotion.
• Lot/Batch number – the manufacturing batch the sample represents.
• METRC Transfer Number – a tracking identifier tied to the state’s seed-to-sale tracking system, which follows the product through the regulated supply chain.
• Collection, received, and finalized dates – the chronology of when the sample was taken, received by the lab, and reported.
• Laboratory information and license number – identifying the accredited lab that performed the testing.

When you compare a COA to a product, the header is where you confirm you are looking at the right document. A COA for a different batch may be perfectly valid and still not describe the package in your hand. This is the core reason responsible programs encourage patients to verify the COA tied to their specific package rather than relying on a generic example posted online.

The Cannabinoid Potency Panel

The cannabinoid potency section is usually the first data table and the one patients care about most. It reports how much of each cannabinoid the sample contains, typically expressed three ways:

• mg/g — milligrams of the cannabinoid per gram of product (a concentration).
• mg/package — the total milligrams in the entire package.
• mg/serving — the milligrams in a single defined serving or dose.

The table lists many individual cannabinoids – THC, THCA, CBD, CBDA, CBG, CBGA, CBN, CBC, THCV, and others – because a complete analytical panel screens for all of them whether or not they are present. For most products in Alabama’s market, the dominant active cannabinoid is delta-9-tetrahydrocannabinol (THC), and many of the minor cannabinoids read as not detected.

“Total THC,” “Total CBD,” and why the math matters

You will notice both “THC” and “Total THC” lines, and they are not always the same number. This reflects the chemistry of the raw plant. In growing cannabis, most THC exists as its acidic precursor, THCA, which is not intoxicating until it is heated and converted—a process called decarboxylation. Laboratories calculate Total THC to express the maximum THC potentially available after that conversion, using a standard formula that adds the directly measured THC to the THCA content adjusted by a molecular-weight conversion factor (approximately 0.877, because a molecule is lost during decarboxylation).

For a finished, already-decarboxylated product such as a gel cube or tincture, the THCA is often fully converted, so “THC” and “Total THC” values are close or identical. Understanding this distinction prevents a common misreading: a high THCA number on raw material does not mean the same number of “active” milligrams without heating, and the Total THC figure is the more meaningful indicator of potency in a finished ingestible.

Reading “ND” and “less-than” values

Two notations cause more confusion than anything else on a COA:

• ND (Not Detected) means the laboratory’s instruments did not detect the compound at all – it was below the limit of detection.
• A “less-than” symbol (<) followed by a number—for example, <0.095 – means the compound, if present, was below the limit of quantitation: the lowest level the lab can reliably measure as a specific value. In practical terms, the lab is reporting that the substance is either absent or present only in trace amounts beneath the threshold at which it can assign a precise figure.

Neither notation is cause for alarm; for contaminants, both are exactly what a patient wants to see. The distinction matters mainly for interpretation: “ND” and “<[number]” both communicate “not present at a measurable, meaningful level,” with the second simply naming the threshold used.

The Contaminant Panels: What is Being Screened Out

The majority of a COA is devoted not to what should be in the product, but to what should not. These contaminant panels are the heart of consumer-safety testing, and a compliant product passes all of them. The standard panels in Alabama’s program include the following.

Heavy metals

The heavy-metals panel screens for arsenic, cadmium, lead, and mercury, expressed in parts per million (ppm). These elements can accumulate in cannabis because the plant readily draws metals from soil and water. On a compliant COA, each appears as a “less-than” value beneath the regulatory action limit, indicating the metal is either absent or present only in trace amounts below the threshold of concern.

Pesticides

The pesticide panel is among the longest sections, screening for a defined list of agricultural chemicals – compounds such as abamectin, bifenthrin, imidacloprid, myclobutanil, and many others – each reported in ppm. Cannabis intended for medical use is held to strict pesticide limits because patients may use products regularly and because certain qualifying conditions involve compromised health. A compliant result shows each pesticide below its limit or not detected.

Residual solvents

When cannabinoids are extracted and concentrated, solvents may be used in processing. The residual-solvents panel confirms that any such solvents – acetone, benzene, butane, hexane, and others – have been removed to below safe thresholds, again expressed in ppm. Benzene in particular is held to a very low limit because of its toxicity. Seeing each solvent reported as a small “less-than” value is the expected, reassuring result.

Microbials

The microbial panel screens for biological contaminants: total yeast and mold, Enterobacteriaceae, coliforms, Shiga-toxin–producing E. coli, Salmonella, and several Aspergillus species. Pathogenic organisms such as Salmonella and the screened Aspergillus species should read “Not Detected.” This panel is especially important for any patient with a weakened immune system.

Mycotoxins

Mycotoxins are toxic compounds produced by certain molds. The panel screens for total aflatoxins (B1, B2, G1, and G2) and ochratoxin A, measured in parts per billion (ppb). These are screened separately from the microbial panel because the toxins can persist even when the mold that produced them is gone.

Filth and foreign matter

A straightforward but meaningful check, this confirms the absence of physical contaminants – reported simply as “Not Detected” on a compliant product.

The Terpene Panel

Many COAs include a terpene profile, listing aromatic compounds such as beta-caryophyllene, linalool, limonene, alpha-pinene, and others, usually in mg/g, with a total terpene percentage. Terpenes contribute to a product’s aroma and are the subject of considerable scientific interest, though claims about their effects should be read cautiously. For the purposes of reading a COA, the terpene panel is descriptive: it characterizes the product’s chemical profile rather than certifying anything about safety. A dedicated companion article explores terpene science and the limits of current evidence in more depth.

Label Potency Versus Tested Potency

One subtlety deserves direct attention because it confuses many patients. The labeled potency of a product (for example, “25 mg”) is a product specification, while the tested potency on any single COA reflects what the laboratory measured in one specific sample. Natural variation in manufacturing means a single batch’s tested value may differ slightly from the round number on the label.

This is normal and expected across all of agriculture and manufacturing. The responsible way to interpret it is to treat the label as the product’s stated specification and the COA accompanying your individual package as the authoritative record of that package’s verified contents. When the two are read together—label for the specification, package COA for verification – patients get an accurate picture without being misled by the inevitable small differences between a round label number and a precise laboratory measurement.

How to Verify Your Specific Package

Because a COA describes the sample tested, the most reliable verification is always batch-specific. Compliant programs increasingly route patients to the exact certificate tied to their package – commonly by scanning a QR code on the packaging that links to the corresponding laboratory results and seed-to-sale record. This approach is more trustworthy than a static COA posted on a website, because it guarantees the data you are reading corresponds to the product you actually hold.

When you verify a package, work through this short checklist:

1. Match the batch. Confirm the lot/batch number on the package matches the COA.
2. Confirm the lab. Check that an accredited, licensed state testing laboratory issued the report.
3. Read the contaminant panels. Confirm heavy metals, pesticides, solvents, microbials, and mycotoxins are all within limits or not detected.
4. Check the potency. Confirm the cannabinoid content is consistent with the product’s labeled specification.
5. Note the dates. A current COA tied to your batch is more meaningful than an old or unrelated one.

Key Takeaways

• A COA is an independent laboratory record of a product’s contents, issued by an accredited state testing laboratory that is separate from the manufacturer [1][2].
• The identity header ties the data to a specific batch; always confirm you are reading the COA for your package.
• “ND” means not detected; a “less-than” value means below the limit of quantitation – both are reassuring on contaminant panels.
• “Total THC” accounts for decarboxylation and is the most meaningful potency figure for finished ingestibles.
• The contaminant panels – heavy metals, pesticides, residual solvents, microbials, mycotoxins, and filth – are the core of safety testing.
• Verify the COA tied to your individual package, ideally via the package’s QR code, rather than relying on a generic example.

Commitment to Alabama Compliance Standards

At Homestead Health, we are committed to transparency and strict compliance with all Alabama regulations. We encourage all patients to prioritize their health and legal standing by seeking only authorized, in-person care by a physician explicitly registered and recognized on AMCC’s website as a valid certifying physician.

It’s the right thing to do and the only way to remain compliant with Alabama’s medical cannabis regulatory guidelines.

Homestead Health Good Manufacturing Practices (GMP)

To support Alabama medical cannabis patients, Homestead Health products undergo rigorous testing protocols (Rule 538-X-6-.04). This includes high-performance liquid chromatography (HPLC) testing for cannabinoid potency and gas chromatography-mass spectrometry (GC-MS) for contaminants. We ensure that our products are free of:

• Heavy metals (lead, arsenic, mercury).
• Microbial pathogens (mold, yeast, salmonella).
• Residual solvents (from the extraction process).

Medical and editorial note: Homestead Health is a licensed medical cannabis processor and does not make medical claims. The information provided is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. All persons must speak to a licensed, state-registered physician to be diagnosed and/or recommended medical cannabis for a qualifying medical condition in the state of alabama.

Alabama Residents Also Ask

Article References

Citations Used For This Article

1. Bhamwiki / Alabama Medical Cannabis Commission. “Alabama Medical Cannabis Commission” (independent state testing laboratory role within the licensed supply chain). https://www.bhamwiki.com/w/Alabama_Medical_Cannabis_Commission
2. Green Health Laboratories – Alabama Medical Cannabis Testing Laboratory (License TLAB000202), Foley, AL. Certificate of Analysis documentation and standard laboratory disclaimers.
3. Alabama Medical Cannabis Commission. “Patients, Caregivers, & Physicians” (program structure and product oversight). https://amcc.alabama.gov/patients/
4. Alabama Medical Cannabis Commission. “Frequently Asked Questions” (approved products and program testing requirements). https://amcc.alabama.gov/frequently-asked-questions/

Additional Reading

• How Alabama Regulates Medical Cannabis: The Compassion Act and the AMCC
• Our Process: From Seed to Sale at Homestead Health
• Rosin vs. Distillate Gummies: Alabama Medical Cannabis Guide
• Understanding Chronic Pain & Alabama’s Medical Cannabis Program
• Medical Cannabis Terpenes: A Guide to Alabama’s Clinical Care