How to read a cannabis lab test report
A cannabis lab test report, often called a certificate of analysis (COA), records what a laboratory found in a particular sample. It may cover potency, terpene profile, pesticides, heavy metals, microbes and residual solvents. The key word is sample: a credible report links its numbers to a named product and batch rather than making a vague claim about an entire brand.
In Australia, the lawful route matters. Many people obtain medicinal cannabis through a participating GP and an authorised prescription pathway; SEEK is one example, not the sole route. Authorised products carry Australian registration and supply information, while recreational cannabis remains illegal in most jurisdictions. The ACT permits limited household cultivation under strict conditions, but that is not the same as a nationwide retail market.
A report can help compare products, verify a label and flag unwanted residues. It cannot guarantee every item in a package, determine whether a product is legal to possess, or replace the directions supplied by a prescriber or manufacturer. For illicit or unlabelled goods, a polished PDF may still be copied from another batch or describe a sample no one can connect to what was sold.
Read the report in a fixed order: identify the product and batch, confirm which tests were performed, interpret the units, then examine potency and safety results. Keep the document with the packaging. In Australia, legal status, driving rules and product storage remain separate decisions from laboratory performance.
Separate laboratory evidence from service claims
Begin by separating laboratory findings from retail promises. A COA is evidence about tested attributes of a sample. Delivery speed, price and a satisfaction guarantee say nothing about potency or purity. They may describe service quality, but a batch-linked report is the relevant evidence for claims about what is inside a cannabis product.
Atlantic Green Cross publishes its Halifax delivery expectations for daily home service across Halifax Regional Municipality, including a $40 minimum order and a 1–3 hour guarantee or a free order. Those conditions concern fulfilment in Nova Scotia, not chemical quality, and they do not indicate that the retailer delivers in Australia.
Match the product and batch
Match the report to the exact flower, edible, concentrate, pre-roll, vape or CBD product in your hand. Look for the product name, format, batch or lot number, package size and sometimes a QR code. A report for “Sativa 10 g” cannot validate a different flower merely because both came from the same producer. Photographs can help when an outer box has been separated from the inner pouch.
Also confirm whether the document reports the finished retail product or only the starting material. A flower COA and a concentrate COA may contain different panels, even when both list THC. For a concentrate cartridge, hardware fit is another layer: a cartridge battery guide can explain compatible power and charging habits, but it says nothing about the oil’s purity or potency.
Decode potency numbers
Potency figures only compare well when their units match. A percentage by mass means grams per 100 g: 18.4% equals 184 mg per 100 g, or 1.84 mg/g. Laboratory documents may instead report mg/g, mg per container or mg per serving. Do not convert a per-serving figure into a package total without checking the declared serving size and net weight.
Total THC may be the measured sum of several cannabinoids, or a “total” calculated after converting acidic forms such as THCA to THC. Read the formula and footnotes rather than assuming two reports use the same method. CBD, CBN and minor cannabinoids are often reported separately; a long list does not automatically mean a stronger or better product.
| Report entry | What it means | Common mistake | Useful comparison |
|---|---|---|---|
| 18.4% THC by mass | 184 mg of THC per 100 g of material | Comparing it directly with a per-serving amount | Confirm the percentage and total-THC definition |
| 5 mg/g THC | The same potency as 0.5% by mass | Reading it as 5% | Match the units before comparing batches |
| 20% total THC | May include THCA converted to THC | Assuming all 20% is directly measured THC | Read the calculation method and footnotes |
| 12 mg THC per serving | The amount in one labelled serving | Assuming the whole package contains 12 mg | Check serving size and net weight |
| CBD not detected | The lab found none above its detection limit | Treating it as proof of absolute zero | Compare the stated detection limits |
| Pesticide at 0.02 ppm | A detected residue equal to 0.02 parts per million | Calling it safe or unsafe without context | Check the compound, threshold and legal limit |
Use the report as a comparison tool, not a dosing calculator. For prescribed medicinal products, follow the label and clinician’s instructions. For a legal hemp product with a stated CBD concentration, compare servings rather than percentages, since a small percentage can still produce a meaningful milligram amount.
Read terpene and contaminant results
The terpene section identifies volatile compounds such as limonene, myrcene or linalool. GC or GC–MS testing can quantify them, while “not detected” only means none was found above the method’s detection limit. A simple aroma description is not a laboratory profile, and the presence of a terpene does not prove the expected flavour, potency or effects.
The safety panel matters more than a decorative terpene chart. Check whether pesticides, mycotoxins, lead, arsenic, cadmium, mercury, harmful microbes or residual solvents were tested. “None found” is reassuring only when the named compounds, detection limits and pass criteria are shown. Vitamin E acetate and other additives may be absent from a flower COA because the laboratory analysed plant material, not the liquid used in a vape.
Verify methods and laboratory credentials
Treat the laboratory and method details as quality checks. Look for the laboratory’s legal name, address, accreditation or recognised quality standard, report date and an authorised signatory. Confirm that the methods suit the matrix: microbial testing for dried flower is not interchangeable with residual-solvent testing for an oil, and a cannabinoid assay may not measure degradation products.
Check the sample dates. A report created long after harvest may describe an older batch, while a fresh report does not validate an old package. Expiry, retest and storage conditions reveal whether the result is still commercially relevant. If two documents disagree, compare batch numbers, units and footnotes before trusting either.
Apply results within Australian rules
Use results to match a product to the intended outcome without turning laboratory numbers into medical promises. Higher THC is not automatically better, and CBD is not a universal answer to sleep, pain or anxiety. For legal products, the dosage form and labelled amount remain central; for medicinal cannabis, a pharmacist or prescriber can explain how the cannabinoids and product directions fit together.
Language and numeracy can also distort interpretation. A consumer who needs help with a report can ask a pharmacist or accredited interpreter, and EspaNet language support may help with material in another language. A sales page that converts a complicated laboratory result into a single percentage without explaining its source should not replace the original report.
Preserve the record and protect the product
Store the report with the product or in a digital folder organised by batch. Keep the original package, receipt and any signs of tampering because those details support traceability. For products obtained legally in Australia, use the labelled storage range and keep the product in its original, child-resistant packaging, away from children and pets.
Be careful when transporting a prescribed product through a city commute in Sydney, Melbourne or Brisbane. Keep it sealed, discreet and inaccessible to passengers, and comply with local possession and transport rules. Driving law varies by state and territory, and detectable THC can create penalties even where the medicine itself was lawfully supplied.
The strongest-looking percentage is not the report’s main message. Its value comes from traceability: the exact product, exact batch, tested contaminants, credible method and honest interpretation. The point to remember is that the product and batch must match the lab test, the units and detection limits must be clear, and unexplained discrepancies deserve caution before use.