How to Read a Mushroom Supplement COA: What the Numbers Actually Mean
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The short answer: A Certificate of Analysis (COA) is a document from an independent lab verifying what's actually in a supplement. For mushroom products, the key numbers to check are: beta-glucan content (should be 20%+ for quality fruiting body extracts), alpha-glucan content (high numbers suggest grain filler), heavy metals (should be below regulatory limits), pesticide residues (should be zero), and microbial safety. If a brand doesn't publish batch-specific COAs from a recognized independent lab, you have no way to verify their claims.
If you've spent any time researching mushroom supplements, you've probably seen brands throw around the term "third-party tested." It sounds reassuring. It's meant to. But what does it actually mean? And more importantly, how do you read the document that supposedly proves it?
A Certificate of Analysis is the single most useful tool for evaluating whether a mushroom supplement contains what it claims. It's also the document most consumers never look at, partly because brands don't make it easy to find, and partly because no one has explained how to read one.
That changes here. This is a practical guide to reading a mushroom supplement COA, line by line, so you can evaluate any product on the market, including ours.
What a COA actually is
A COA is a lab report. An independent laboratory, not the manufacturer, tests a sample of the product and reports what they find. It's the difference between a company saying "our product contains 30% beta-glucans" and an outside lab confirming it.
The key word is independent. A COA from the manufacturer's own lab is like grading your own homework. It might be accurate. But it doesn't carry the same weight as verification from a recognized third-party lab like Eurofins, SGS, NSF, or ConsumerLab.
A valid COA should include: the lab's name and accreditation, the date of testing, a batch or lot number matching the product you purchased, and the actual test results. If any of these are missing, the document is incomplete at best.
The numbers that matter
Beta-glucan content
This is the single most important number on a mushroom supplement COA. Beta-glucans are the primary bioactive polysaccharides responsible for much of the immune-modulating and systemic effects studied in clinical research. A systematic review of 34 randomized controlled trials found beta-glucan doses of 250 to 1,000mg per day effective for immune outcomes (Vlassopoulou et al., 2021).
For quality fruiting body extracts, you want to see beta-glucan content of 20% or higher. Premium extracts often test at 30% to 50%+.
There's a critical nuance here: the testing method matters. There are two primary approaches.
Enzymatic assay testing (like the Megazyme method) specifically measures fungal beta-glucans. It can distinguish between mushroom polysaccharides and grain starch. This is the accurate method.
Proximate analysis is cheaper but measures total polysaccharides without distinguishing source. A mycelium-on-grain product can show high polysaccharide numbers while most of that content is rice starch, not fungal beta-glucans. If a COA uses proximate analysis on a mycelium-on-grain product, the numbers may look impressive while being mostly irrelevant.
Look for which method was used. If the COA doesn't specify, it's probably proximate analysis.
Alpha-glucan content
Alpha-glucans are the indicator for starch content. In a fruiting body extract, alpha-glucan should be low, typically under 5%. In mycelium-on-grain products, alpha-glucan is often 30% to 50%, because most of what's in the product is grain.
One nuance worth noting: some mushrooms, particularly Cordyceps militaris fruiting bodies, naturally contain glycogen and trehalose, which can register as alpha-glucans in testing. Updated testing methods (from 2023 onward) account for this. So a slightly elevated alpha-glucan reading in Cordyceps isn't necessarily a red flag, but it should be explained by the manufacturer. In most other species, high alpha-glucan means grain filler.
Heavy metals panel
Mushrooms are natural bioaccumulators. They absorb substances from their growing environment, which means heavy metal testing isn't optional, it's essential.
A complete heavy metals panel tests for lead, cadmium, arsenic, and mercury. The numbers should be reported in parts per million (ppm) or micrograms per gram, and compared against regulatory limits.
We test against California Proposition 65 limits, which are the strictest consumer safety thresholds in the United States. Most of our results come in at 95%+ below these limits. If a COA doesn't specify which standard the results are compared against, it's harder to evaluate whether the numbers are actually safe.
Pesticide screening
A comprehensive pesticide panel tests for 70 or more compounds. For quality products sourced from reputable growers, the target is zero detected across the entire panel.
This matters especially for mushrooms sourced from regions with less regulated agricultural practices. Quality Chinese growers (where 85% of the world's medicinal mushrooms are cultivated) can and do pass comprehensive pesticide screening. The question isn't the country of origin, it's whether the testing was done. See our article on why most mushroom supplements fail for more on sourcing quality.
Microbial testing
Standard microbial panels include total plate count (overall bacterial load), yeast and mold, coliforms, E. coli, and Salmonella. All should be within established safe limits or absent entirely. This is a basic safety check that any legitimate manufacturer should pass.
Active marker compounds
Beyond beta-glucans, some species have specific marker compounds that indicate quality:
Reishi: Ganoderic acids (triterpenes). These are the compounds linked to Reishi's calming, sleep-supporting, and HPA-axis-modulating effects. They require alcohol extraction to access. If a COA shows high beta-glucans but no ganoderic acid data, the product may have good immune support but limited sleep and stress benefits.
Cordyceps: Cordycepin and adenosine. These are the compounds associated with ATP production and energy support.
Lion's Mane: Hericenones (from fruiting body). These are the NGF-stimulating compounds linked to cognitive benefits. Not all COAs test for these specifically, but brands that do are demonstrating a higher level of quality verification.
Red flags on a COA
No lab name or accreditation. A legitimate COA comes from a named, accredited laboratory. If the document doesn't identify the lab, it may be an internal test presented to look like third-party verification.
No batch number. A valid COA is batch-specific. Every production run should have its own test results. If a brand shows one COA for all their products across all batches forever, that's a marketing prop, not quality verification.
Only "polysaccharides" listed, no beta-glucan specification. Total polysaccharides include starch. Beta-glucan is the number that actually matters. If only total polysaccharides are reported, especially on a mycelium product, the number is likely inflated by grain content.
No heavy metals or pesticide data. If these panels are missing, the testing is incomplete. These aren't optional extras, they're safety fundamentals.
Outdated results. A COA from two years ago doesn't tell you what's in the batch you're purchasing today. Look for recent, batch-specific results.
Results that seem too perfect. Zero across every single line item can sometimes indicate a templated document rather than actual testing. Real lab results typically show trace amounts of some elements, with the key being that they're well below safety thresholds.
How to actually get a COA
The best brands publish COAs directly on their website, often with a QR code on the product packaging that links to the specific batch results. This is the gold standard for transparency.
If COAs aren't published, email the company and ask for the COA for your specific batch (the lot number is usually on the bottom of the bottle). If they won't provide it, or if they provide a generic document without batch-specific data, draw your own conclusions.
We publish our Eurofins COAs and make them accessible because we believe quality that's real should be quality that's verifiable. See our full third-party test results.
A practical example
Here's what you'd see on a quality mushroom supplement COA, using our own results as an example:
Lab: Eurofins (globally recognized, independently accredited)
Testing method: Enzymatic assay for beta-glucans (Megazyme method)
Beta-glucan content: 54.6% (Reishi batch). This is well above the 20% minimum for quality extracts.
Alpha-glucan: Low, confirming minimal grain starch content (fruiting body source verified).
Heavy metals: Lead, cadmium, arsenic, mercury, all 95%+ below California Prop 65 limits.
Pesticides: 70+ compounds tested. Zero detected.
Microbial: Total plate count, yeast and mold, coliforms, E. coli, Salmonella, all within safe limits or absent.
Every number is verifiable. Every claim is backed by an independent document. That's what transparency looks like when it's real. For the full quality framework, see our mushroom supplements buying guide.
FAQ
What is a COA for supplements? A Certificate of Analysis is a document from an independent laboratory verifying the contents of a supplement. It tests for active compound levels (like beta-glucans), contaminants (heavy metals, pesticides), and microbial safety. It's the objective proof behind label claims.
How do I read a mushroom supplement COA? Focus on five key areas: beta-glucan content (should be 20%+ for fruiting body extracts), alpha-glucan content (low means minimal grain filler), heavy metals panel (should be below regulatory limits), pesticide screening (should show zero detected), and the testing lab's name and accreditation (should be an independent, recognized laboratory).
Why don't all mushroom brands publish COAs? Publishing batch-specific COAs requires investment in third-party testing for every production run. Some brands test internally but don't use independent labs. Others may not test at all. Brands that publish independent COAs are demonstrating confidence in their product quality and accountability to their customers.
What beta-glucan percentage is good for mushroom supplements? For fruiting body extracts, 20% is the minimum threshold for a quality product. 30% to 50%+ indicates a premium extract. Mycelium-on-grain products often test below 10% for actual fungal beta-glucans. The testing method matters: enzymatic assay (Megazyme) is more accurate than proximate analysis for distinguishing mushroom beta-glucans from grain starch.
What is the difference between beta-glucans and polysaccharides on a COA? Beta-glucans are a specific type of polysaccharide with documented bioactivity. "Total polysaccharides" includes beta-glucans but also includes starch and other non-bioactive carbohydrates. A COA that only lists total polysaccharides without specifying beta-glucan content may be inflating numbers with grain starch content.
Your body already knows how to regulate. It just needs the right support.
RESO and STASE are a two-formula mushroom system designed around your body's natural circadian rhythm. Morning activation. Evening restoration. 4,000mg of research-backed fruiting body extract per day, third-party tested by Eurofins.
Not a quick fix. A daily practice.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.