Learn how to read a CBD certificate of analysis, from matching the batch number to understanding ND and LOQ for THC and converting mg/g into mg per serving.
A broad-spectrum CBD product may be labeled THC-free, but how can you verify that claim? A certificate of analysis (COA) provides laboratory results showing a tested batch's cannabinoid content and, depending on the testing panel, its contaminant results.
Knowing how to read a CBD COA helps you verify the batch, compare cannabinoid levels with the product label, and understand what a non-detect THC result actually means. These checks are becoming especially relevant as the new federal limit of 0.4 mg of total THC per container approaches in December 2026. [Link “new federal limit” to the October post “What the December 2026 Hemp Rule Means for Your CBD” once it is live.]
Here is how to interpret a CBD certificate of analysis, from the batch number to the cannabinoid profile, using cbdMD's official COA resource.
What Is a CBD Certificate of Analysis?
A CBD certificate of analysis is a laboratory report that documents test results for a product sample. It typically includes cannabinoid concentrations and may also cover heavy metals, pesticides, residual solvents, and microbial contaminants.
For broad-spectrum CBD, the report can help establish whether the tested sample's cannabinoid profile supports the manufacturer's THC-free claim. However, the results apply only to the tested product and batch. A report for another batch does not verify the contents of your package.
How to Read a CBD COA Step by Step
1. Match the Batch Number to Your Product
Before interpreting the results, confirm the COA matches your product by checking the name, formulation, and batch or lot number against the details on the package. Some products also include a QR code that links directly to laboratory results.
cbdMD's COA page helps customers find product testing information. Because inventory changes, the report linked to a product page may not correspond to the batch you received. If the batch numbers differ, request the correct report before relying on the results.
2. Know Where to Find the Results
Once you've located the correct report, start with its summary. According to cbdMD's COA guidance, the first page summarizes CBD content, whether THC was detected, total cannabinoid content, and terpene content. It also shows that the product passed safety testing for residual solvents, pesticides, heavy metals, and biological impurities.
The following pages provide more detail. The second page breaks down the full cannabinoid profile, while the third covers the terpene panel. A short glossary at the bottom of the first page explains unfamiliar abbreviations.
This layout gives you a practical order for reviewing the report: check CBD and THC first, then examine the other cannabinoids, and finally review the safety results.
3. Understand ND, LOD, and LOQ
Three laboratory terms matter most when evaluating a THC-free claim.
- ND (Not Detected): The laboratory did not detect the compound at or above the applicable detection threshold.
- LOD (Limit of Detection): The lowest concentration at which the method can reliably distinguish a compound from background noise.
- LOQ (Limit of Quantitation): The lowest concentration at which the method can measure a compound with acceptable accuracy and precision.
A result below LOQ may mean a compound was detected but could not be measured reliably. The laboratory's reporting conventions determine how the report presents such findings.
The distinction matters because ND does not prove absolute zero THC. It means THC was not detected using the stated method at its applicable threshold. A result showing THC detected below LOQ is different from ND.
When reviewing a COA, check the laboratory's notes for the detection and quantitation limits. These help you understand what a non-detect result can and cannot establish.
4. Calculate THC per Container
A COA may report THC concentration in milligrams per gram (mg/g), while the new federal limit is stated in milligrams per container. You cannot compare these figures directly without calculating the total amount.
For a product measured by mass, use:
Total THC (mg) = THC concentration (mg/g) × product mass (g)
For example, consider a hypothetical product containing 20 g of material with a measured THC concentration of 0.02 mg/g:
0.02 mg/g × 20 g = 0.4 mg THC per container
This example illustrates the calculation only. It is not an actual cbdMD laboratory result or evidence that a product complies with a particular regulation.
For oils and other liquids, check whether the concentration is reported by mass or volume. If the result is in mg/g, you need the product's mass in grams. To convert milliliters to grams, you need the liquid's density.
If THC is reported as ND, you cannot calculate an exact total from that result alone. You would need the detection limit and enough information to interpret it relative to the entire container.
The 0.4 mg-per-container limit makes this distinction important. Before concluding that a product complies, confirm the applicable rule, effective date, and testing requirements. An ND result does not automatically establish compliance with every THC threshold.
5. Convert mg/g into Milligrams per Serving
A COA may report CBD concentration in mg/g rather than the amount in an individual serving. If you know the serving's mass, you can calculate the corresponding amount.
CBD per serving (mg) = CBD concentration (mg/g) × serving mass (g)
For example, suppose a COA reports 6.25 mg/g of CBD and a single gummy weighs 4 g:
6.25 mg/g × 4 g = 25 mg CBD per gummy
The calculation works when both measurements use compatible mass units. For liquids, do not automatically treat milliliters as grams; use the manufacturer's product information or the relevant density data. For gummies, use the mass of an individual gummy rather than assuming every piece weighs the same.
After calculating the amount, compare it with the label. If the figures differ substantially, contact the manufacturer for clarification.
6. Interpret the Minor Cannabinoid Rows
The cannabinoid profile helps explain what else is present alongside CBD in a broad-spectrum formulation.
Depending on the product and laboratory testing panel, the report may include:
- CBG (cannabigerol): Another cannabinoid naturally found in hemp.
- CBN (cannabinol): A cannabinoid that can form as THC breaks down.
- CBC (cannabichromene): Another naturally occurring cannabinoid.
- CBDA (cannabidiolic acid): The acidic precursor to CBD.
- THC-related compounds: Such as delta-9 THC and THCA, depending on the panel.
cbdMD describes its broad-spectrum formula as containing CBD alongside other cannabinoids and terpenes, with THC removed. Its process page explains the company's broad-spectrum extraction approach.
When reading an individual COA, focus on the actual results rather than assuming every product contains the same compounds or concentrations. A numerical result indicates a measured amount, while ND means the compound was not detected at the applicable threshold.
The profile helps you understand the tested sample's composition. It does not show that a product delivers a specific benefit, or that a formula with more minor cannabinoids is necessarily better.
7. Check the Other Quality and Safety Results
Cannabinoid content is only one aspect of product quality. Depending on the testing panel, a COA may also report:
- Heavy metals: Including lead, arsenic, cadmium, and mercury.
- Pesticides: Residues from cultivation.
- Residual solvents: Substances that may remain after extraction or manufacturing.
- Microbial contaminants: Certain bacteria, yeasts, and molds.
- Mycotoxins: Compounds produced by some fungi.
Check the reported results against any stated acceptance limits, and look for pass/fail assessments where provided. A blank section does not mean a substance was absent; it may not have been tested.
cbdMD states that its products are tested by independent, ISO-accredited laboratories. When reviewing any COA, remember that accreditation speaks to the laboratory's competence, but the scope of that accreditation also matters.
What a CBD COA Can and Cannot Tell You
A properly matched COA helps you evaluate the tested batch's cannabinoid profile, compare CBD content with the label, and interpret THC and contaminant results.
However, it does not guarantee that every unit in a batch has identical contents. ND does not prove absolute zero THC, and a cannabinoid profile alone cannot establish how a product will work for you.
If the report is missing, does not match the batch, or conflicts with the label, ask the manufacturer for clarification.
Make the COA Part of Your Buying Checklist
Start by matching the batch number, verifying the cannabinoid profile, understanding ND and LOQ, and calculating cannabinoid amounts when the necessary information is available.
These steps help you evaluate a broad-spectrum CBD product using laboratory evidence rather than relying on its label alone. For cbdMD products, start with the official COA lookup and check the report for your specific batch, or browse our broad-spectrum CBD collection.
Frequently Asked Questions
What does ND mean on a CBD COA?
The laboratory did not detect the compound above its applicable detection threshold.
Is ND the same as less than LOQ?
No. Less than LOQ may mean the compound was detected but could not be measured reliably.
Does broad-spectrum CBD contain zero THC?
Not necessarily. An ND result does not guarantee absolute zero THC.
How do I know if a COA matches my product?
Match the batch or lot number on the package to the number on the report.
Can I calculate THC per container from a COA?
Yes, if the THC concentration is quantified and the product's mass, or volume and density, is known.