How to Read a Cannabis COA: Understanding Cannabis Lab Results

Knowing how to read a cannabis COA can help you move beyond marketing claims and understand what a laboratory actually reported about a tested sample.

A Certificate of Analysis—usually shortened to COA—is a laboratory report that can contain information about cannabinoid content, terpenes where tested, pesticides, residual solvents, heavy metals, microbial impurities, mycotoxins, and other analyses depending on the product and applicable testing program.

But simply finding a PDF labeled “Lab Results” isn’t enough.

Before looking at the THC percentage, first establish whether the report actually corresponds with the cannabis product you’re evaluating.

Then review the laboratory, sample and batch information, testing dates, cannabinoid results, contaminant panels, reporting limits, and overall pass/fail status.

This guide explains each section so you can read a cannabis lab report with much more confidence.

What Is a Cannabis COA?

A Certificate of Analysis is a document issued by a laboratory after analyzing a submitted cannabis or cannabis-product sample.

Depending on the testing program and jurisdiction, a COA can report results for areas such as:

Cannabinoids
Terpenes
Residual pesticides
Residual solvents and processing chemicals
Heavy metals
Microbial contaminants
Mycotoxins
Moisture content
Water activity
Foreign material

California’s Department of Cannabis Control, for example, requires licensed laboratories to report regulatory compliance results on a COA and identifies cannabinoids, residual solvents, pesticides, heavy metals, microbial impurities, mycotoxins, moisture/water activity, and foreign material among its testing categories.

Testing requirements vary between U.S. jurisdictions, so not every COA will contain the exact same panels or limits.

That’s an important point to remember throughout this guide.

The Most Important COA Check Comes Before the Results

Many people open a lab report and immediately look for the THC number.

Start somewhere else.

First ask:

Does this COA actually belong to the product or batch I’m holding?

A perfectly legitimate cannabis laboratory report is not useful for product verification if it describes a completely different batch.

Look for identifying information such as:

Product name
Sample name
Batch or lot number
Production batch number
Sample ID
Client or producer name
Product type
Testing date
Laboratory report number

Compare those details with the information available on the product packaging.

Ideally, there should be a logical connection:

Product packaging → batch identifier → laboratory sample → COA

Batch matching is so important that California’s distributor guidance specifically requires the COA to correspond to the correct batch and the product label to remain consistent with applicable cannabinoid and terpenoid information on the COA.

This is also why our Whole Melt Extracts Verification Guide emphasizes matching identifiers rather than relying only on QR codes or packaging appearance.

Step 1: Identify the Testing Laboratory

A COA should identify the laboratory responsible for the analysis.

Look for information such as:

Laboratory name
Laboratory address
License information where applicable
Accreditation information
Contact information
Report or certificate number

A laboratory name alone doesn’t tell you whether the report corresponds with your product, but it gives you an identifiable organization behind the results.

What Does ISO/IEC 17025 Mean?

You may see ISO/IEC 17025 referenced on cannabis laboratory documents.

ISO/IEC 17025 is an international standard used for the competence of testing and calibration laboratories.

Cannabis testing laboratories can receive accreditation to this standard for relevant testing activities. ANAB, for example, operates an ISO/IEC 17025 accreditation program covering cannabis laboratories performing chemical and microbiological analyses.

Accreditation is a meaningful laboratory-quality signal, but it still does not eliminate the need to make sure the report corresponds with the product you’re checking.

Step 2: Find the Sample and Batch Information

This section may be called:

Sample Information
Sample Details
Batch Information
Client Information
Test Sample
Product Information

Terminology varies by lab.

Look for identifiers that allow the sample to be traced.

Batch Number

A batch number identifies a particular production lot or group.

When available on both the product and COA, compare the values carefully.

A mismatch should be investigated.

Sample ID

The laboratory may assign its own internal sample number after receiving material for testing.

This won’t necessarily be identical to the manufacturer’s batch number.

A COA can therefore contain both:

Producer’s batch/lot number

and

Laboratory sample ID

Don’t confuse the two.

Product Name

Check whether the name and product type make sense.

If you’re evaluating a vape product and the laboratory report clearly identifies an unrelated flower sample, the report should not be assumed to verify your vape merely because the brand name appears somewhere on it.

Step 3: Check the Dates

COAs can contain several dates.

You may see:

Sample received date
Testing start date
Testing completion date
Report date
Date of analysis

These dates help establish when the sample moved through the laboratory process.

A very old report attached to a newly produced batch deserves additional scrutiny if there is no reasonable explanation connecting the two.

Age requirements can also be jurisdiction-specific. California’s current distributor guidance, for example, says the regulatory compliance COA associated with the batch must be less than 12 months old.

That should not be interpreted as a universal national rule for every cannabis product.

Step 4: Understand the Cannabinoid Panel

The cannabinoid panel is often the section readers recognize first.

It may report compounds such as:

Δ9-THC
THCA
CBD
CBDA
CBG
CBGA
CBN
CBC
Other cannabinoids included in the laboratory’s method

Not every laboratory tests or reports exactly the same list.

THC vs. THCA

These are related but different compounds.

Δ9-THC is the psychoactive cannabinoid commonly referred to as THC.

THCA is the acidic precursor that can convert into THC when heated through a process called decarboxylation.

This is why a COA can show both THCA and Δ9-THC separately.

CBD vs. CBDA

The same basic distinction applies:

CBD is the neutral cannabinoid.

CBDA is its acidic precursor.

What Does “Total THC” Mean?

Total THC generally attempts to account for both directly measured Δ9-THC and the potential THC contribution from THCA after decarboxylation.

However, you shouldn’t assume every displayed number was calculated identically without checking the laboratory’s reporting method or applicable regulations.

For consumers, the most important point is:

THCA percentage and Δ9-THC percentage should not simply be added together as though they were identical measurements.

Percentage vs. mg/g: Why Cannabis COAs Use Different Units

Cannabinoid concentrations can be reported in several forms.

Common formats include:

Percentage (%)
Milligrams per gram (mg/g)
Milligrams per package
Milligrams per serving

Percentage

If a flower or concentrate is listed at a particular percentage, the number represents a mass-based concentration.

For a simplified conversion:

1% = approximately 10 mg/g

So a laboratory result of 20% corresponds to roughly 200 mg/g.

This conversion helps explain why one report might display:

20.0% THC

while another displays:

200 mg/g

Those values represent approximately the same concentration.

Milligrams Per Package

Manufactured cannabis products may also display cannabinoid content based on the entire package or individual serving.

For example, California labeling requirements for manufactured cannabis products use THC and CBD amounts in milligrams per package, with serving amounts also required for certain products.

Always check the unit before comparing two numbers.

Step 5: Read the Terpene Panel

Terpenes are aromatic compounds found in cannabis and many other plants.

When terpene testing is performed, the COA may identify compounds such as:

Myrcene
Limonene
β-Caryophyllene
α-Pinene
β-Pinene
Linalool
Humulene
Terpinolene

The report may show each terpene as:

Percentage
mg/g
Another concentration unit

What Does Total Terpenes Mean?

Some reports add individually detected terpenes together and present a Total Terpenes value.

This can help summarize the analyzed profile.

However, terpene results should not be interpreted as guaranteed effects.

A laboratory can measure chemical concentration; a terpene result does not prove that every consumer will experience a particular mood, therapeutic result, or subjective effect.

Is Terpene Testing Always Required?

No.

Testing rules vary.

For example, California’s current cannabis regulations include terpenoid methods if tested, rather than treating the terpene panel identically to every mandatory contaminant category.

So the absence of a terpene panel does not automatically mean a COA is invalid.

Step 6: Understand “ND,” “LOD,” and “LOQ”

This is where cannabis COAs become much easier to misunderstand.

Three abbreviations appear frequently:

LOD

LOQ

ND: Not Detected

ND generally means the laboratory did not detect the analyte at or above its specified detection threshold.

It does not necessarily mean:

“There are literally zero molecules of this substance.”

Analytical instruments have detection limits.

LOD: Limit of Detection

The Limit of Detection is the lowest level at which the laboratory’s method can reliably detect that an analyte is present.

Below that level, the laboratory cannot confidently distinguish the analyte from analytical noise.

LOQ: Limit of Quantitation

The Limit of Quantitation is the lowest level at which the laboratory can reliably measure and report the amount of the analyte with the required quantitative performance.

A simple way to remember the difference:

LOD = Can we reliably detect it?

LOQ = Can we reliably quantify how much is there?

What Does “<LOQ” Mean?

If a result says:

<LOQ

it means the analyte may have been detected or present at a level below what the method can reliably quantify.

That is different from simply treating the result as a precise zero.

Understanding this distinction is particularly useful when reading contaminant and minor-cannabinoid panels.

Step 7: Read the Pesticide Results

Pesticide testing looks for specified pesticide residues.

A COA may list individual compounds along with:

Reported result
LOD
LOQ
Action level
Pass/fail status

What Is an Action Level?

An action level is a regulatory or program threshold used to determine whether the tested concentration meets the applicable requirement.

This is different from the LOD or LOQ.

Remember:

LOD = analytical detection capability

LOQ = analytical quantitation capability

Action level = regulatory/compliance threshold

For example, California requires laboratories to report residual pesticide results and indicate pass or fail based on applicable action levels.

Do not assume the same numerical pesticide thresholds apply in every state.

Step 8: Check the Heavy Metals Panel

Cannabis testing programs may analyze metals such as:

Lead
Cadmium
Arsenic
Mercury

These elements can present concerns at sufficient exposure levels, which is why regulated testing programs may establish action limits.

The COA should show whether the tested sample met the applicable requirements.

Again, pay attention to:

Result
Unit
LOQ/LOD where shown
Action level
Pass/fail result

Don’t compare numbers from different reports without checking the units.

A value reported in µg/g should not be compared blindly with a number reported in another unit.

Step 9: Read the Residual Solvents Panel

Residual-solvent testing is particularly relevant to products manufactured using extraction processes that involve solvents.

The laboratory may test for specified compounds associated with extraction or processing.

Depending on the applicable program, these can include different solvents and processing chemicals.

The report may display:

Analyte → measured amount → action limit → result

A passing result means the sample met the applicable laboratory/regulatory criterion for the analytes evaluated.

It does not mean the laboratory has proven the product contains absolutely no trace of every chemical that could theoretically exist.

That’s an important distinction between testing compliance and an unlimited purity guarantee.

Step 10: Check Microbial Testing

Microbial panels evaluate specified microorganisms or microbial contamination.

Depending on the jurisdiction and product, testing may include organisms such as:

Certain pathogenic bacteria
Certain molds or fungi
Other regulated microbial targets

The exact panel varies.

Results may appear as:

Present / absent
Detected / not detected
Quantitative counts
Pass / fail

Don’t assume two laboratories using differently presented microbial panels are testing precisely the same targets.

Step 11: Understand Mycotoxin Testing

Mycotoxins are toxic compounds produced by certain fungi.

Cannabis testing programs may screen for specific mycotoxins where required.

On the COA, these usually appear within a contaminant section and should be compared with the applicable action levels.

A passing mycotoxin panel refers to the analytes that were tested under that program.

It should not be interpreted as a claim that every conceivable biological contaminant was tested.

Step 12: Look at Moisture and Water Activity

These measurements are easy to confuse.

Moisture Content

Moisture content tells you how much water is present in the sample by mass.

Water Activity

Water activity relates more closely to how available that water is for processes such as microbial growth and other stability-related changes.

They are not interchangeable measurements.

This section is generally more relevant to certain cannabis formats than others.

California includes moisture content and water activity among its cannabis testing categories.

Step 13: Find the Overall Pass or Fail Result

Some COAs provide a clear overall status near the top or bottom:

PASS

FAIL

Others show pass/fail results within each individual testing panel.

A regulatory COA may indicate whether the batch met the requirements for each substance or analysis. California specifically describes the COA as reporting whether a batch passes or fails the applicable testing.

Don’t let a large green PASS prevent you from reading the rest of the report.

You still want to establish:

What was tested
Which sample was tested
What limits were used
Whether the identifiers match your product

Cannabis COA Example: What Each Section Tells You

COA Section	What You’re Looking For	Main Question
Laboratory	Name, license/accreditation information	Who performed the testing?
Product information	Product/sample name and type	What was tested?
Batch/lot	Matching product identifier	Does this report belong to my batch?
Dates	Received/tested/reported dates	When was it tested?
Cannabinoids	THC, THCA, CBD and other results	What cannabinoids were measured?
Terpenes	Individual terpene concentrations	What aromatic compounds were reported?
Pesticides	Results vs. action levels	Did tested pesticides meet requirements?
Heavy metals	Results vs. action levels	Did tested metals meet requirements?
Residual solvents	Results vs. applicable limits	Did the tested sample meet solvent requirements?
Microbial	Detected/not detected or counts	Did microbial testing meet requirements?
Mycotoxins	Measured results	Did tested mycotoxins meet requirements?
LOD/LOQ	Method sensitivity	What could the method detect or quantify?
Overall status	Pass/fail	Did the sample meet the applicable testing criteria?

The table is useful for orientation, but the batch match remains the most important authenticity question.

How to Tell Whether a Cannabis COA Is Relevant to Your Product

Use a simple cross-check.

1. Check the Product Name

Does it correspond with your package?

2. Match the Batch or Lot Number

Where both are provided, they should correspond.

3. Check the Product Type

Flower documentation shouldn’t automatically be applied to a vape or concentrate.

4. Check the Dates

Do they make sense relative to the product and batch?

5. Compare Labeled Cannabinoid Information

Where applicable, determine whether the packaging and COA are reasonably consistent.

6. Check the Laboratory

Make sure there is an identifiable lab behind the report.

7. Review the Complete Testing Panel

Don’t judge the entire COA from the potency section.

This process is particularly important when using laboratory documentation as part of product authentication.

Can a QR Code Link to a COA?

Yes, product packaging may use a QR code or other digital link to make laboratory information easier to access.

But scanning successfully doesn’t automatically complete the verification process.

After opening the COA:

match it to the product.

A copied QR code could theoretically direct multiple products to the same laboratory report.

What matters is whether the identifying information creates a reasonable connection between the report and the particular product or batch.

For Whole Melt products, our Verify Authentic Product resource provides an additional verification pathway.

What a Cannabis COA Does Not Prove

A COA can be valuable, but it has limits.

A report does not automatically prove:

Every Unit Was Individually Tested

Laboratory compliance testing generally involves representative samples drawn from batches rather than individually testing every retail unit.

Every Possible Contaminant Was Tested

Laboratories test specific analytes included in their methods or regulatory requirements.

A Product Will Produce a Specific Effect

Chemical analysis cannot guarantee how a particular person will experience a cannabis product.

Higher THC Means Higher Quality

THC concentration is one laboratory measurement, not a universal quality score.

A Product Is Authentic Just Because a COA Exists

The report needs a meaningful connection with the product or batch.

“Not Detected” Means Absolute Zero

ND is tied to the analytical capabilities and reporting limits of the test method.

Common Red Flags When Reading a Cannabis COA

Some issues deserve further investigation.

The Batch Numbers Don’t Match

A report for another batch shouldn’t be casually substituted for the product in front of you.

No Laboratory Is Clearly Identified

You should be able to determine who performed the testing.

The Product Type Is Wrong

A laboratory report for a completely different product doesn’t verify your product.

The Report Is Missing Important Pages

Some COAs span several pages.

A potency page alone may not show contaminant results.

Units Are Unclear

A number without a meaningful unit is difficult to interpret correctly.

The QR Code Leads to a Generic COA

Check whether the report contains product-specific or batch-specific information.

The Packaging Claims Don’t Match the Report

Significant unexplained discrepancies between labeling and laboratory information deserve investigation.

Only the Highest THC Number Is Highlighted

A COA contains much more useful information than one potency figure.

Why the Highest THC Percentage Isn’t Necessarily the Best COA

Cannabis shopping often reduces lab reports to one number.

That misses most of their value.

A COA can tell you about:

Product identity
Cannabinoid composition
Terpene profile where tested
Contaminant screening
Reporting limits
Regulatory compliance
Batch traceability

A product with a larger THC number isn’t automatically more authentic, cleaner, better produced, or more appropriate for a particular consumer.

Potency is a characteristic.

It is not a complete quality assessment.

Cannabis COA Terms Worth Knowing

Term	Meaning
COA	Certificate of Analysis
Analyte	Substance the laboratory is measuring
Batch/Lot	Identified group of product associated with production/testing
Sample ID	Identifier assigned to a tested sample
ND	Not detected at the laboratory’s applicable detection threshold
LOD	Limit of Detection
LOQ	Limit of Quantitation
Action Level	Threshold used for applicable compliance decisions
Pass	Sample met the relevant criterion for the reported analysis
Fail	Sample exceeded or otherwise failed the relevant criterion
mg/g	Milligrams per gram
µg/g	Micrograms per gram
Total THC	Calculated/reported measure incorporating applicable THC forms
Total Cannabinoids	Combined reported cannabinoids according to the laboratory’s calculation

Knowing these terms makes even a dense laboratory report much easier to navigate.

A 60-Second Cannabis COA Checklist

If you don’t want to analyze every line immediately, use this quick sequence:

If the batch relationship cannot be established, investigate before treating the report as evidence about the product.

How COAs Fit Into Whole Melt Extracts Verification

For Whole Melt products, laboratory documentation should be one part of a broader verification process.

A strong verification chain looks like:

Seller

↓

Whole Melt product

↓

Packaging

↓

Product/batch identifier

↓

Verification information

↓

Relevant COA

The COA is most useful when it supports that chain rather than existing as an unrelated document.

Our products are independently lab tested, and verification support is available when customers need help assessing product information.

For the full process, read our Whole Melt Extracts Verification Guide or use our product verification page.

Frequently Asked Questions

What is a COA for cannabis?

A cannabis Certificate of Analysis is a laboratory report containing results for a tested sample. Depending on the product and applicable testing program, it may include cannabinoid results, terpenes, pesticides, heavy metals, residual solvents, microbial testing, mycotoxins, and other analyses.

How do I know if a cannabis COA is legitimate?

Start by identifying the testing laboratory and determining whether the report contains meaningful sample, product, batch, and testing information. Then check whether those identifiers correspond with the product you’re evaluating. A professional-looking PDF alone isn’t sufficient product verification.

What does ND mean on a cannabis lab report?

ND generally means not detected at or above the method’s applicable detection threshold. It should not automatically be interpreted as an absolute chemical zero.

What is the difference between LOD and LOQ?

LOD is the lowest level at which an analytical method can reliably detect an analyte. LOQ is the lowest level at which the method can reliably quantify its concentration. In simple terms, LOD asks whether something can be detected; LOQ asks whether its amount can be reliably measured.

What does “pass” mean on a cannabis COA?

A pass generally means the tested sample met the applicable criteria for that analysis, such as remaining below an established action level for a specified contaminant. Requirements and thresholds can differ between jurisdictions and product categories.

How can I tell if a COA matches my cannabis product?

Compare the product name, batch or lot number, product type, sample information, testing dates, and other identifiers with the packaging. The stronger the traceable connection between the physical product and laboratory sample, the more relevant the COA is.

Does a high THC percentage mean a cannabis product is better?

No. THC concentration describes one part of the cannabinoid profile. It doesn’t independently establish authenticity, overall quality, contaminant status, flavor, terpene composition, or how an individual consumer will experience the product.

Does a clean COA guarantee a cannabis product is safe?

A COA reports the results of specific tests performed on a sample using defined methods and thresholds. It should not be interpreted as an unlimited guarantee covering every possible substance, every individual retail unit, or every potential risk.

Read the Entire COA, Not Just the THC Number

Learning how to read a cannabis COA becomes much easier once you stop treating it as a potency certificate.

Start with identity.

Which laboratory tested the sample? What product was tested? Does the batch match? When was it tested?

Then move through the chemistry:

Cannabinoids → terpenes → contaminants → reporting limits → pass/fail status.

Understand the difference between ND, LOD, LOQ, and an action level. Check the units. And most importantly, establish that the laboratory report actually belongs to the product or batch you’re evaluating.

That approach turns a complicated laboratory document into a useful product-verification tool.

Checking a Whole Melt product? Continue with our Whole Melt Extracts Verification Guide or use our Product Verification page to review the next step.