How to Read a Cannabis Potency COA

A Certificate of Analysis is the single most important document attached to any cannabis product sold in Michigan — and one of the least understood by the people relying on it every day. If you're a processor, a dispensary buyer, or just a cultivator trying to make sense of your own results, here's what's actually on that document and what it means.

Start With the Header Information

Before you even get to numbers, confirm the basics: the lab's name and license number, the batch or lot number matching your own records, the sample collection date, and the testing date. This sounds obvious, but a COA attached to the wrong batch is a real and recurring problem in the supply chain. Cross-check it every time.

The Cannabinoid Panel

This is usually the first table you see, listing individual cannabinoids — THCA, Delta-9 THC, THC (total), CBDA, CBD, CBD (total), and often minor cannabinoids like CBG or CBN depending on the lab's panel.

A few things to look for:

• Total THC vs. Delta-9 THC. Raw cannabis contains mostly THCA, which converts to active Delta-9 THC when heated (decarboxylation). "Total THC" is typically calculated as THCA × 0.877 + Delta-9 THC, accounting for that conversion. If a COA only shows Delta-9 THC and ignores THCA, the number will look artificially low for flower.
• Units matter. Results are usually shown both as a percentage by weight and in milligrams per gram or milligrams per package — make sure you're comparing the same unit when evaluating two products or two labs.
• The label variance. Michigan labeling rules acknowledge that the actual cannabinoid content of a product may vary somewhat from the number printed on the label. If you're a processor, this is exactly why batch-to-batch consistency in your production process matters — the tighter your process, the less risk you carry on this front.

The Contaminant Panels

Below or alongside potency, most COAs include pass/fail results for the other mandatory panels: pesticides, heavy metals, microbials, mycotoxins, and — for flower — moisture content. For edibles and infused products, you should also see a homogeneity result, confirming the cannabinoids are evenly distributed across servings rather than concentrated in a few "hot spots."

Each of these is typically reported as either a simple pass/fail against the regulatory action limit, or as a detected concentration alongside that limit. If a report only shows "Pass" with no numbers, ask the lab for the underlying data — you want to know how close a result was to the limit, not just which side of the line it landed on.

Measurement Uncertainty

A rigorous COA will note measurement uncertainty somewhere, usually as a plus-or-minus value next to each result. This exists because no analytical method is perfectly precise — the reported number is the lab's best estimate, with a defined range around it. This matters most for results that sit close to a regulatory limit or a label claim: a value that's technically "passing" but very close to the edge, with a wide uncertainty band, deserves more attention than one comfortably in the middle of the range.

Method and Instrument Notes

Many labs list which analytical method was used for each panel — HPLC for potency, LC-MS/MS for pesticides, ICP-MS for heavy metals, GC-MS for residual solvents and terpenes. You don't need to be a chemist to read a COA, but knowing the method is there if you ever need to compare results across two labs that returned different numbers for the same product.

Signatures and Accreditation Statement

A legitimate COA is signed off by an authorized reviewer at the lab and typically references the lab's accreditation (such as ISO/IEC 17025) and its CRA license number. If either is missing, that's worth a direct question to the lab.

Why This Actually Matters

A COA isn't paperwork you file and forget. It's the document a retail buyer, an inspector, or a customer will eventually scrutinize — and it's the fastest way to catch a production issue before it becomes a recurring, expensive one. Reading it carefully, batch after batch, is one of the simplest quality habits a cultivator or processor can build.

If you'd like a walkthrough of your own COAs from Prism Triangle, our team is happy to go through a report line by line with you.

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This article is for general informational purposes and reflects common cannabis testing and COA conventions. Always confirm current Michigan CRA requirements and action limits directly with the agency, as figures and rules are subject to change.