How to Read a Mushroom Supplement COA (Certificate of Analysis)

A Certificate of Analysis (COA) is the single most important document when evaluating a mushroom supplement. It's the difference between trusting a brand's marketing claims and actually verifying what's in the product. Yet most consumers have never seen one, let alone know how to read one.

This guide will teach you exactly what to look for.

💡 Key TakeawayA COA is the only way to verify what's actually in your mushroom supplement. If a brand can't provide one, walk away — no matter how good their marketing looks.

What Is a COA?

A COA is a document issued by a laboratory — ideally a third-party, independent lab — that reports the results of analytical testing on a specific product batch. It typically covers identity verification, potency/active compounds, and safety testing (contaminants).

Think of it like a home inspection report for supplements. It tells you what's actually in the bottle.

Where to Find COAs

Reputable mushroom supplement brands publish COAs on their website, often on individual product pages or a dedicated "Lab Results" section. If a brand doesn't make COAs available, that's a red flag. You can always email a company and request the COA for a specific batch number (found on your product's label).

The Key Sections of a Mushroom Supplement COA

1. Lab Information

The top of the COA should identify the testing laboratory. Look for accredited labs — ISO 17025 accreditation is the gold standard. Common labs in the mushroom supplement space include Eurofins, ALS Global, and Medallion Labs. If the testing was done "in-house" by the supplement company itself, the results are less trustworthy.

2. Product Identity

The COA should clearly identify the product tested, including the brand name, product name, batch/lot number, and date of testing. The batch number should match what's on your product label.

3. Beta-Glucan Content

This is the most important metric for functional mushroom supplements. Beta-glucans are the primary bioactive polysaccharides responsible for immune modulation and other health benefits.

What to look for:

Good: Beta-glucan content above 20% (fruiting body extracts typically range 20-60%)
Great: Above 30% beta-glucans
Red flag: Below 10%, or beta-glucans not tested at all
Major red flag: "Polysaccharides" listed instead of beta-glucans — polysaccharide testing includes starch, which means mycelium-on-grain products can show high polysaccharide numbers that are mostly grain starch, not bioactive compounds

⚠️ Red Flag"Polysaccharides" listed instead of beta-glucans is the oldest trick in the book. Polysaccharide testing counts starch from grain substrates, so a mycelium-on-grain product can show 60%+ "polysaccharides" that are mostly rice starch — not bioactive mushroom compounds.

The Megazyme assay is the industry-standard method for beta-glucan testing. If you see this method referenced, that's a good sign.

4. Triterpene Content (for Reishi and Chaga)

For reishi and chaga specifically, triterpene content matters. These alcohol-soluble compounds are responsible for many of the adaptogenic and anti-inflammatory effects. Look for triterpene content above 2% for reishi products.

5. Heavy Metals Testing

Mushrooms are bioaccumulators — they absorb substances from their growing environment, including heavy metals. Every COA should test for at least four heavy metals:

Lead (Pb): Should be below 0.5 ppm (parts per million). California Prop 65 limit is 0.5 μg/day.
Arsenic (As): Should be below 1.0 ppm for inorganic arsenic.
Cadmium (Cd): Should be below 0.5 ppm.
Mercury (Hg): Should be below 0.1 ppm.

"Not detected" (ND) is the best result. Any result above the limits mentioned should give you pause.

6. Microbial Testing

This checks for bacterial and fungal contamination:

Total Aerobic Count: Should be below 100,000 CFU/g
Yeast and Mold: Should be below 1,000 CFU/g
E. coli: Should not be detected
Salmonella: Must not be detected
Coliforms: Should be below 100 CFU/g

7. Pesticide Residues

Not all COAs include pesticide testing, but the best ones do. Organic-certified products should be tested for a panel of common pesticides with all results below detection limits.

Red Flags That Should Make You Walk Away

No COA available at all — If a brand can't or won't show you test results, move on.
"Polysaccharides" instead of beta-glucans — This is the oldest trick in the book for hiding low-quality mycelium-on-grain products.
In-house testing only — Third-party testing is essential for credibility.
Outdated COAs — A COA from 3+ years ago doesn't tell you about today's product.
Missing heavy metals panel — This is basic safety testing. No excuse to skip it.
The COA doesn't match the product — Check that the batch number and product name align.

A Real-World Example

Let's say you're evaluating a lion's mane capsule product. Here's what a good COA should look like:

✅ Third-party lab (ISO 17025 accredited)
✅ Beta-glucans: 28% (Megazyme method)
✅ Heavy metals: All below limits (Pb <0.2 ppm, As <0.3 ppm, Cd <0.1 ppm, Hg: ND)
✅ Microbial: All pass
✅ Identity confirmed: Hericium erinaceus fruiting body
✅ Date: Within the last 12 months
✅ Batch number matches product label

✨ Pro TipSave this checklist to your phone. Next time you're at a headshop, pull it up before buying any mushroom supplement. Or photograph the label and check these points at home.

How ShrooMap Uses COA Data

At ShrooMap, we incorporate COA verification into our product rating methodology. Brands that provide transparent third-party testing receive higher trust scores, and we flag products that lack proper documentation. You can see COA status on individual product pages throughout our brand directory.

Take Action

Next time you're shopping for a mushroom supplement — whether at a local headshop or online — ask for the COA before you buy. Any brand worth your money will be happy to provide it. Use our product comparison tool to evaluate options that have been independently verified.

Species-Specific What to Look For Beyond Beta-Glucans

Different mushrooms have different key bioactive compounds. Here's what to look for specifically for each major species:

Reishi: Ask for triterpene content. Ganoderic acids are responsible for reishi's adaptogenic and anti-inflammatory effects, and they're only captured by alcohol extraction. A quality dual-extracted reishi COA shows both beta-glucan content (≥15% for reishi) AND triterpene content (≥2%). If it only lists polysaccharides without triterpenes, it's water-only extracted and you're missing half the medicine.

Lion's Mane: Beta-glucan content plus identity confirmation as H. erinaceus fruiting body. High-end brands test for hericenone content, but this isn't yet industry standard. Beta-glucans ≥20% from verified fruiting body is the minimum. Alpha-glucan content should be very low (<5%).

Turkey Tail: Should show some of the highest beta-glucan percentages of any species — 30-60% is normal for quality fruiting body extracts. Low beta-glucan content (<20%) in turkey tail is a strong signal of mycelium-on-grain filler.

Cordyceps Militaris: Cordycepin content matters significantly. A good militaris extract COA shows cordycepin ≥0.15% (quality products test above 0.3%). Low cordycepin means lower-quality raw material or excessive dilution. Beta-glucans should still be ≥20%.

The Alpha-Glucan/Beta-Glucan Ratio: The Most Important Single Number

Pure mushroom fruiting body: HIGH beta-glucans, LOW alpha-glucans. Mushrooms don't contain starch — they contain fungal beta-glucans. Alpha-glucan content in a pure mushroom extract should be minimal (<5%).

Mycelium on grain: LOW beta-glucans, HIGH alpha-glucans. The grain substrate contributes massive amounts of starch. A typical mycelium-on-grain product: 5% beta-glucans, 45% alpha-glucans. If beta-glucans divided by total glucans is less than 50%, you're looking at a grain product. Good products have beta-glucan ratios of 85-95% of total glucan content.

Some brands only report "total polysaccharides" and omit the alpha/beta breakdown entirely. This is the classic red flag. Grain starch is a polysaccharide. A "50% polysaccharides" claim might be 40% starch and 10% actual mushroom compounds. Always demand specific beta-glucan AND alpha-glucan numbers separately. When shopping at headshops, ask staff if they can pull up the COA for any product you're considering — a shop that can access this documentation is one that takes quality seriously.

Frequently Asked Questions

How often should a company update their COA?

COAs should be batch-specific and no older than 12-18 months for current product. A COA from 3 years ago doesn't tell you about today's product. Reputable brands test every production batch and make COAs available by batch number — some have QR codes on the product linking directly to the specific batch's COA. This is the gold standard for transparency and consumer trust.

Can I request a COA from a brand directly?

Yes, and you should if it's not posted on their website. Email or live chat with the batch number from your product label. If a brand refuses to provide a COA, dismisses the request, or says their testing is "proprietary," that's a serious red flag. Any legitimate supplement company has testing documentation — it's required for manufacturing compliance. "Proprietary" is code for "the results would embarrass us."

What's the difference between a COA and an "Organic Certification"?

Completely different documents covering different things. Organic certification verifies the mushrooms were grown without synthetic pesticides or fertilizers. A COA is an analytical test of the actual product that verifies identity, potency, and safety. Both can coexist — but you want a COA regardless of organic status. Organic oat powder in a capsule is still oat powder. The COA tells you what's in the bottle; organic certification only tells you how the raw material was grown.

Why do some brands list "polysaccharides" instead of "beta-glucans" on their label?

Because polysaccharides testing is cheaper and catches grain starch, inflating the numbers. Polysaccharides includes alpha-glucans (starch), beta-glucans (actual mushroom compounds), and other carbohydrates. A product can show 60% polysaccharides while only containing 5% actual beta-glucans — the rest is rice. Beta-glucan testing (Megazyme method) specifically isolates fungal beta-glucans from starch. Brands that list polysaccharides instead of beta-glucans without explanation should be questioned. Our fruiting body explainer digs into this sleight of hand in detail.

What should I do if a product fails one of the COA checks?

Depends on what failed. Heavy metals above limits: don't take it, consider returning it, report to FDA if levels are extreme. Beta-glucans below 10%: you've bought a low-quality product — stop buying it, look for alternatives. Identity not confirmed: possible adulteration — don't consume, inform the retailer. Outdated COA: contact the brand for current batch documentation. If they can't provide it, switch brands. Your leverage is purchase decisions — vote with your wallet for brands that take testing seriously.

Advanced COA Reading: Catching Sophisticated Adulteration

The basic COA check (beta-glucans high, alpha-glucans low, heavy metals pass, identity confirmed) catches most quality problems in the supplement market. But as consumers get better at demanding COAs, some bad actors have gotten better at providing misleading documentation. Here's what sophisticated adulteration looks like and how to catch it.

Batch switching: A brand produces one high-quality batch, gets an excellent COA, and uses that COA for all subsequent batches that may use cheaper material. The fix: check that the batch number on the COA matches the batch number on your product. If the brand only has one COA for all products regardless of batch number, that's a red flag.

In-house testing: Some brands conduct their own testing rather than using third-party labs, then present this as a "COA." In-house testing has obvious conflicts of interest — the company being tested is running the test. Real third-party COAs come from ISO 17025-accredited independent laboratories (Eurofins, Intertek, NSF International, Nammex, Agiliti Health). If the "lab" on the COA is affiliated with the supplement brand or you can't find it independently, it's likely in-house testing. Treat it accordingly.

Testing the raw material, not the finished product: A technically accurate COA can show excellent beta-glucan content for the mushroom extract ingredient, while the actual capsule or gummy product is heavily diluted with fillers. Ask specifically whether the COA is for the raw extract or the finished product. You want finished product testing — the thing actually in the bottle.

Outdated heavy metals limits: Heavy metals standards vary by country and have been progressively tightened as the health impacts of low-level heavy metal exposure have become better understood. Some brands display COAs that passed older, less stringent limits that would fail current California Prop 65 standards or NSF requirements. Check that the limits on the COA match current regulatory standards — for lead specifically, current guidance for frequent-use supplements is 0.5 ppm or below for adults, 0.1 ppm for children's products.

The microbial pass with no methodology: A COA that shows "microbial contamination: PASS" without listing the specific tests, limits, and numerical results is providing minimal information. You want to see specific colony-forming unit counts for total aerobic bacteria, yeast, mold, and explicit "not detected" results for pathogens like E. coli and Salmonella. A COA that just says "PASS" on microbial without the details leaves too much room for selective reporting.

For the vast majority of purchases from quality brands, these sophisticated issues don't arise — you're looking for basic transparency, not forensic accounting. But knowing these patterns makes you a more informed buyer. Our curated products in the capsules, tinctures, and gummies categories have been evaluated against these quality criteria. Use our tools as a starting point, then develop your own verification habit as you identify brands you trust.

Building Your Verification Practice

Learning to read a COA once is useful. Making COA verification a consistent practice before every significant supplement purchase is valuable. Here's how to build the habit efficiently without making it onerous.

For products you buy regularly from brands you've already verified: you don't need to re-read the full COA every order. What you need to check: is this the same batch as last time (batch number on the product matches previous orders), and has the brand changed any of their sourcing or testing claims recently? A quick scan of their current website for changes is sufficient. Brands that consistently produce excellent COAs and have been doing so for years have earned a degree of trust that makes the full verification process unnecessary for every purchase.

For new brands or products: full verification, no exceptions. Check: third-party ISO-accredited lab (not in-house), beta-glucan percentage (species-specific minimums above), alpha-glucan percentage (should be low for fruiting body products), heavy metals (all within limits), microbial results (specific numbers, not just "PASS"), identity confirmation (species, part used, DNA verification if available), and batch date match to product. This takes 5-10 minutes for a product you're considering spending $30-50/month on. Non-negotiable if you're making health decisions based on the product.

Crowdsource verification in the community: r/FunctionalMushrooms on Reddit has users who regularly discuss and post COA analysis for major brands. If you're evaluating a brand someone else has already scrutinized, the community may have done significant due diligence work that you can benefit from. This doesn't replace checking yourself — community consensus can be wrong, and brands change their sourcing over time — but it's a useful efficiency tool, particularly for identifying brands with well-known quality problems that you can avoid outright.

Keep records: when you find a brand whose COA passes all your criteria, keep a note of what you verified and when. Build a personal "trusted brands" list that you update periodically as you verify new products or as existing brands' quality changes. This transforms COA verification from a per-purchase chore into a progressive knowledge base about the market. Over time you'll have a curated list of brands you trust, brands you've ruled out, and new entrants you haven't evaluated yet. ShrooMap's product ratings and comparison tools give you a starting point for this list, with quality criteria already evaluated for the products in our capsules, gummies, and mushroom coffee categories.

The COA as a Market Signal: What It Tells You Beyond Chemistry

A COA tells you about the product. But a company's willingness to provide a COA also tells you about the company — and that signal is worth reading.

Brands that proactively display COAs on their product pages, link to them via QR code from the product packaging, post them by batch number, and update them when batch numbers change have made a deliberate choice to build their brand on transparency. That choice costs something: testing is expensive (comprehensive COAs from labs like Eurofins run hundreds to thousands of dollars per batch), and it creates accountability — if a test result is disappointing, there's no way to hide it from customers who've been directed to check the COA. Brands that choose this level of transparency are betting their reputation on consistent quality. That's a meaningful signal.

Brands that provide COAs only when pressed, that have generic "batch COAs" with no specific product connection, that provide in-house testing documentation instead of third-party data, or that simply don't have COAs available at all have made a different choice. They've chosen opacity. That choice is also meaningful. It doesn't definitively prove their products are bad — some legitimate brands simply haven't prioritized documentation systems. But it removes the primary mechanism by which you can verify their quality claims. Without a COA, you're trusting their marketing, not their chemistry.

Use this framework when evaluating new brands: a company that makes it easy to find and verify their quality documentation has earned more trust than one that makes it difficult, regardless of how impressive their marketing is. The brands in ShrooMap's curated capsules, gummies, and mushroom coffee categories are selected in part based on documentation transparency. Our comparison tools incorporate quality verification status as a core evaluation criterion, giving you a shortcut to the brands that have done the transparency work.

Your Next Steps

You now have everything you need to evaluate functional mushroom supplement quality. The practical workflow is simple: when you find a product you're considering, go to the brand's website, find the COA section (usually under "quality," "lab testing," or "transparency"), pull up the most recent batch COA for your specific product, and run through the five-point check: beta-glucans above minimum, alpha-glucans low, heavy metals below limits, identity confirmed as species and plant part claimed, microbial results with specific counts. This takes 5-10 minutes and is the single highest-ROI quality action you can take as a supplement consumer.

For brands that don't make COAs easily accessible, send an email asking for the COA for the specific batch you're considering purchasing. Their response — or lack thereof — tells you something important about how seriously they take quality accountability. Brands with nothing to hide make it easy to find the data. Brands with something to hide make it difficult or impossible.

ShrooMap has done this due diligence work for the products in our curated categories. Our capsules, gummies, tinctures, and mushroom coffee categories feature products that have met our quality verification standards. Use our platform as a starting point, develop your own COA verification habit for ongoing purchases, and you'll never again wonder whether the functional mushroom supplement you're taking actually contains what it says on the label.