How to Read a Mushroom COA (Lion's Mane Edition)

A COA (certificate of analysis) is a lab report documenting a product's tested composition — and for mushroom supplements it's the only reliable way to tell real extract from grain-grown filler.

Plenty of supplement categories let you take quality on trust. Mushrooms don't, because the cheapest way to make a "lion's mane" powder is to grow mycelium on grain and dry it together with that starch — and you cannot see that on the front label. The marketing will say "full-spectrum" or "organic" either way. A COA cuts through it with numbers.

Beta-glucan percentage is the real measure of active mushroom extract. For lion's mane fruiting body, under ~10% is weak or grain-diluted, 20–25% is a solid honest floor, and 30%+ is excellent.

Beta-glucans are cell-wall polysaccharides used as the standardized potency marker for medicinal-mushroom extracts. In plain terms, the beta-glucan % is the closest thing to a straight answer to "how much real mushroom extract is in here?" It's the first number to find on any lion's mane COA.

Place the figure on a simple scale: under about 10% is weak — either a low-grade extract or one diluted with grain starch. Around 20–25% is a solid, honest floor that reputable fruiting-body extracts hit and back with a COA. 30%+ is excellent and near the top of what's credibly disclosed for lion's mane — for instance, FreshCap states 31% on a 14:1 fruiting-body powder, and Real Mushrooms states above 25% with public COAs.

'Total polysaccharides' combines beta-glucan (real extract) and alpha-glucan (grain starch), so a big polysaccharides number can be mostly filler. Only a separately stated beta-glucan figure tells you about real mushroom.

This is the most common sleight of hand on mushroom labels and COAs. Polysaccharides are a broad category, and the two that matter here are very different: beta-glucan is the active mushroom marker, while alpha-glucan is largely grain starch from the growing substrate. A "total polysaccharides" line adds them together.

A trustworthy COA reports beta-glucan and alpha-glucan separately, precisely so you can see the difference. When both are broken out, the comparison itself is the test — which brings us to the alpha-glucan tell.

Alpha-glucan is the grain-starch marker. A COA showing high alpha-glucan and low beta-glucan is the unmistakable signature of mycelium grown on grain — mostly filler, not mushroom.

Here's where reading a COA pays off most. When a lab breaks out alpha-glucan and beta-glucan separately, the ratio between them tells you what you're really buying:

Low alpha-glucan, high beta-glucan → a real fruiting-body extract. The bulk of the measured glucans are the active mushroom marker, with little grain starch. This is what you want.

High alpha-glucan, low beta-glucan → mycelium-on-grain. The product is dominated by leftover starch from the rice or oats the mycelium was grown on, with little actual extract. When labs independently analyze cheap mycelium products, this lopsided pattern is exactly what they tend to find.

A complete mushroom COA also confirms identity (it's genuinely Hericium erinaceus) and tests for contaminants like heavy metals and microbials — glucan content alone isn't the whole safety picture.

Potency is the headline, but a thorough COA covers more. Two sections matter:

Identity / authenticity. A good COA confirms the material is actually the species claimed — lion's mane (Hericium erinaceus) — rather than a mislabeled or adulterated substitute. It's a basic but meaningful check that you're getting the mushroom on the label.

Contaminant testing. Mushrooms can accumulate heavy metals, and supplements can carry microbial or mold contamination. A real COA reports testing for heavy metals and microbials against accepted limits. This is a genuine safety feature — see our lion's mane safety guide for why tested products are the lower-risk choice.

None of these figures are health claims. Beta-glucans, hericenones, and erinacines are studied in preclinical lab and animal research; those are promising signals, not proven human outcomes. These statements have not been evaluated by the FDA, and lion's mane is not intended to diagnose, treat, cure, or prevent any disease.