How to Read COAs (Lab Reports)

Learning how to read a CBD COA (Certificate of Analysis) helps you confirm what’s in your product and what isn’t—especially important when you prefer THC-free options. This cbd lab report guide explains where to look on a lab report, how to verify “THC-free,” and which quality checks matter most.

COAs are typically PDFs from an independent, accredited laboratory. They list cannabinoids (like CBD and THC), any detected contaminants, test methods, dates, and the specific batch tested. Because labels and marketing can vary, the COA is the most reliable snapshot of what was actually measured.

For THC-free choices, your goal is to confirm that Δ9-THC (and often THCA) are either “ND” (not detected) or below the lab’s LOQ (limit of quantitation), and that “Total THC” meets your needs. This page focuses on reading lab reports; for broader safety context, see Safety & Testing rather than duplicating it here.

Disclaimer: Information here is educational and not medical or legal advice. CBD can affect people differently. If you have questions about health conditions, medications, or workplace drug testing, consult a qualified professional.

What Is a COA?

A COA is a third-party lab report that verifies product identity and composition. It usually includes: a product name and batch/lot number; test date; lab name and accreditation; methods; cannabinoid potency; and results for contaminants (pesticides, heavy metals, residual solvents, microbials, and more depending on product type).

Quick Checklist Before You Start

Match the product name and batch/lot on the COA to your package or QR code.
Confirm third-party status and ISO/IEC 17025 accreditation on the lab’s report or website.
Check the test date and ensure results are current for your batch.
Confirm the sample type/matrix (e.g., tincture/oil, gummy, capsule, topical) matches your product.
Look for full-panel testing where appropriate: potency plus contaminants relevant to the product.

Step-by-Step: How to Read a CBD COA (THC-Free)

1) Verify identity and authenticity

Batch or lot number: must match your package. Many labels include a QR code that leads directly to the batch COA.
Look for a chain-of-custody or sample receipt ID and a report number.

2) Check the lab and methods

Accreditation: labs commonly note ISO/IEC 17025 and method identifiers (e.g., HPLC for cannabinoids).
Matrix and units: ensure the method fits the product form and units (percent, mg/g, mg/mL, mg/serving) are clear.

3) Read the cannabinoid profile (potency)

Common fields: CBD, CBDA, Δ9-THC, THCA, (sometimes) Δ8-THC and minor cannabinoids.
Units: percent (%), mg/g (solids), mg/mL (liquids), or mg/serving (edibles/capsules). Note the unit for each line.
Total CBD typically accounts for decarboxylation: Total CBD ≈ CBD + 0.877 × CBDA.
Total THC commonly uses: Total THC ≈ Δ9-THC + 0.877 × THCA. Some labs exclude or separately list Δ8-THC—read the lab’s definition on the report.
THC-free verification: Look for Δ9-THC and THCA reported as ND (not detected) or < LOQ (below the limit of quantitation), and confirm the lab’s Total THC aligns with your requirements (often ND or below LOQ). If Δ8-THC is present, note whether the product still meets your “THC-free” preference.
LOQ vs ND: ND means the analyte was not detected above the method threshold. LOQ is the lowest level the lab can quantify with confidence. Values can be “present but below LOQ” even if shown as ND.

4) Compare potency to the label

For tinctures: mg/mL × serving size (mL) = mg/serving. Check consistency with the label.
For gummies/capsules: mg/serving on the COA should align with the labeled claim for that batch.
Reasonable variance is common (manufacturing and method variability). Large discrepancies are a red flag.

5) Review contaminant panels

Residual solvents (extracts): Confirm “Pass” or that findings are ND/below action limits.
Pesticides: Look for a comprehensive screen with clear “Pass” or ND/below LOQ results.
Heavy metals (e.g., lead, arsenic, cadmium, mercury): Results should be below state or lab limits.
Microbials & mycotoxins: Especially important for ingestibles. Acceptable thresholds vary by jurisdiction and product type.
Water activity/moisture (edibles): Ensures reduced spoilage risk.

6) Other useful sections

Terpenes: Optional but informative for aroma/profile in broad-spectrum products.
Stability/expiration: If provided, shows how potency may change over time (see Stability Testing for more depth).

Reading Units and Simple Conversions

% to mg/g (solids): 1% ≈ 10 mg/g.
% to mg/mL (liquids): mg/mL ≈ % × 10 × density (g/mL). Many tinctures are near 1 g/mL; check the COA for measured density.
mg/mL to mg/serving: multiply by the serving volume (mL).
When in doubt, use the lab’s own “mg/serving” column if provided.

THC-Free and Drug Testing: What to Know

Even when a COA shows “ND” for Δ9-THC and a very low Total THC, drug tests vary in sensitivity, and results can depend on frequency of use, metabolism, and test type. Cross-contamination is also possible in manufacturing. If avoiding any risk is critical, discuss with your employer or testing provider and consider products with clear ND results for Δ9-THC, THCA, and Δ8-THC, verified per batch.

Red Flags on a COA

No batch/lot number or it doesn’t match your product.
Out-of-date report or a “generic” COA not tied to your batch.
No third-party lab or missing accreditation details.
Potency claims without a cannabinoid table or without test methods/units.
No contaminant testing for an ingestible product.
Formatting anomalies (e.g., inconsistent fonts) that suggest editing—verify on the lab’s portal via QR code.

FAQ

What does ND mean on a COA?
ND means “not detected” above the lab’s reporting threshold. It does not necessarily mean absolute zero; it means the analyte is below the lab’s ability to quantify.

What’s the difference between LOD and LOQ?
LOD (limit of detection) is the lowest level the lab can detect; LOQ (limit of quantitation) is the lowest level that can be measured with acceptable precision. COAs often use LOQ for reporting.

How is Total THC calculated?
Labs commonly use: Total THC ≈ Δ9-THC + 0.877 × THCA. Some labs treat Δ8-THC separately; check the report’s definitions to see which compounds are included.

Why do potencies vary between labs or batches?
Natural variability, manufacturing tolerances, sampling technique, and analytical methods can cause small differences. Large gaps warrant follow-up.

Does a “THC-free” COA guarantee I’ll pass a drug test?
No guarantee. While ND results reduce risk, testing protocols and individual factors vary. If zero risk is required, consult your employer/testing provider and choose products with batch-specific ND results.

Can terpenes confirm broad-spectrum content?
Terpene data can support a broad-spectrum profile, but absence on the report doesn’t necessarily mean they are absent in the product—some brands do not test or publish terpene results.

Summary

To read a CBD COA, match the batch, confirm third-party accreditation, check dates and methods, read the cannabinoid table (including Total CBD and Total THC), verify ND or < LOQ for THC if you want THC-free, and review contaminant panels. Use the product’s units to confirm per-serving potency. When something looks unclear, compare the COA to the label and contact the brand or lab for clarification.

Ready to compare real-world examples? Explore verified, THC-free options at CannaGea’s THC-Free collection.