Most people choose cannabis products on strain name, THC percentage and price. Two of those three tell you very little, and the information that would actually help is usually available and rarely looked at.
Knowing how to choose cannabis products properly takes under a minute at the counter.
Not medical advice. TruMo Analytics is an accredited cannabis testing laboratory. This explains how to verify what is in a product. Whether a product is appropriate for you is a question for a clinician.
The Five Checks
1. Find the certificate of analysis
Every product in a regulated market has been tested batch by batch before it reached the shelf. The certificate of analysis is that record, usually accessible via a QR code on the packaging or through the retailer’s website.
If nobody can produce one, treat the product as unverified regardless of how it is packaged or described.
2. Match the batch number
This is the check most people skip and the one that most often matters.
Certificates are batch-specific. A report for a different batch — even the same cultivar from the same producer, harvested the same week — describes different material. The identifier on the packaging must appear on the report.
3. Check the dates
Look at both the sample date and the analysis date. A report from many months ago on product that has been in storage since tells you less than a recent one, particularly for microbial results.
Cannabis changes after testing. Heat, light, humidity and time all affect it, and no certificate accounts for a warehouse that ran warm. See how to store cannabis properly.
4. Confirm contaminants were tested
A potency-only certificate is not a safety document. Look for microbials, mycotoxins, heavy metals, pesticides, and — for concentrates and vapes — residual solvents.
Absence of a contaminant panel is not the same as a clean contaminant panel. See contaminant testing explained.
5. Check the laboratory
The report should name the laboratory, its licence and its accreditation status. ISO/IEC 17025 accreditation means an independent body assessed technical competence, not merely that a licence was issued.
A report with no identifiable laboratory behind it is not evidence.
Reading the Numbers
Total THC is calculated, not measured directly. Raw cannabis contains mostly THCA, which converts to THC when heated. Total THC accounts for that conversion and assumes it is complete — which real heating does not achieve. It is a theoretical maximum. See THC percentage explained.
Percentages and milligrams are not interchangeable. Flower and concentrates are reported as a percentage by weight; edibles and tinctures in milligrams per serving and per package.
“Not detected” is not zero. It means nothing was found above the method’s detection limit. A report that states its detection limits is telling you how strong that statement is.
Look at the full cannabinoid profile, not only total THC. The THC:CBD ratio changes a product’s character more than absolute potency does, and CBN levels indicate age or heat exposure. See cannabinoids explained.
What Higher THC Does Not Mean
Potency is a concentration measurement. It is not a quality rating, and it does not predict how a product will affect you.
It says nothing about how the material was grown or cured, about terpene content, about freshness, or about whether the product suits you. For someone with low tolerance, a very high-potency product is more likely to produce an unpleasant experience than a good one.
The market’s fixation on the THC number is also what creates commercial pressure on laboratories to report favourably — see lab ethics and data integrity.
What the Strain Name Tells You
Less than you would expect. There is no registry of cannabis cultivar names and no authority verifying claims, so the same name from two producers is frequently different material — genetically and chemically.
The indica/sativa/hybrid categories have similarly little chemical basis. See indica, sativa and hybrid explained and cannabis genetics.
The measured chemical profile is the reliable identifier. Track which profiles work for you rather than which names — names are not consistent, chemistry is.
Questions Worth Asking a Budtender
Some questions get useful answers. Others do not.
Useful:
- “Can I see the COA for this batch?”
- “When was this tested?”
- “Does this have terpene data?”
- “What is the CBD content, not just the THC?”
- “Which lab tested this?”
Less useful:
- “Which one will help my anxiety?” — a budtender is a retail employee, not a clinician, and this is a clinical question.
- “Is this indica or sativa?” — the answer carries less information than it appears to.
- “What’s your strongest?” — potency is not the useful variable for most purposes.
A dispensary that can answer the first list is one worth returning to. One that cannot produce a COA on request is telling you something.
Keeping Track
The most useful habit is also the simplest: record what you bought, the batch, the measured profile, the dose, and what happened.
After a few purchases this shows patterns that strain names never will — which cannabinoid ratios and terpene profiles actually work for you. That record is also worth bringing to a clinical appointment. See dosage basics.
If You Grow Your Own
Home-grown cannabis is untested by default. You controlled what you applied; you did not control what was in your soil, your water, or your drying room.
Many laboratories accept samples from individuals, and a home test kit is not an equivalent — kits give a rough potency estimate and do not screen for the contaminants that matter. See home kits versus laboratory testing
The One-Minute Version
Ask for the COA. Match the batch. Check the date. Confirm contaminants were tested. Check the lab is accredited.
That is the whole thing, and it puts you ahead of almost everyone else at the counter. Why it matters is in how third-party testing protects patients.