A Certificate of Analysis (COA) is the closest thing the supplement industry has to a receipt of honesty. It's a lab report that says, "we sent a sample of this batch to an independent laboratory, here is what they actually found." Reading them is a skill, and it's one of the single most useful skills you can develop as a wellness consumer.
This is a walkthrough of what every line on a real COA means, what numbers to care about, and what tricks to watch for. You can follow along by pulling up an actual report from our Certificate of Analysis page.
The Header: Who, What, When
Every legitimate COA starts with four pieces of information: the testing laboratory's name and accreditation, the product being tested (including batch/lot number), the date of testing, and the date of report issuance.
If any of those are missing, the document is not a COA. It's a marketing flyer.
The accreditation matters. ISO 17025 is the gold standard for analytical labs — it means the lab has been audited for its testing methods and its quality systems. If the COA doesn't reference ISO 17025 or an equivalent (UKAS, A2LA), the numbers below are less trustworthy.
Active Compound Content
This is the headline number for any functional mushroom product. For our Lion's Mane products, you'd look for beta-glucan content (ideally measured by the Megazyme assay), hericenones, and erinacines content. For reishi, you'd look for beta-glucans plus triterpenes (specifically ganoderic acids).
The two questions to ask:
- Is the percentage stated for the right thing? "Polysaccharides: 30%" is meaningless — could include starch from the grain substrate. "1,3/1,6 beta-glucans: 25%" is meaningful.
- Is the absolute amount per serving stated? A 30% extract sounds impressive until you realize the serving is 50mg. Always check the math.
Heavy Metal Testing
This is the most important safety section. Mushrooms are bioaccumulators — they absorb heavy metals from their growing substrate. A COA should test for lead, cadmium, arsenic, and mercury at minimum, with results well below California Prop 65 thresholds (the strictest US standard).
Reference ranges to look for:
- Lead: < 0.5 mg/kg (Prop 65 daily exposure limit calculation)
- Cadmium: < 0.5 mg/kg
- Arsenic: < 1.5 mg/kg (inorganic arsenic is the dangerous form)
- Mercury: < 0.1 mg/kg
If the COA shows "Not Detected" with the method's limit of detection stated, that's the cleanest possible result.
Microbial Testing
Mushroom products are biological. Without proper processing, they can grow things you don't want to eat. A real COA tests for total aerobic count, yeast and mold, E. coli, Salmonella, and Staphylococcus.
Pass thresholds:
- Total aerobic count: < 10,000 CFU/g
- Yeast and mold: < 1,000 CFU/g
- E. coli, Salmonella, Staph: absent in 1g
If a COA skips microbial testing, you're being asked to trust the brand without verification.
Pesticide and Solvent Residue
Especially relevant for organic-claimed products. The COA should include either a clean pesticide panel (showing residues below allowed limits or non-detected) or a residual solvent panel (relevant for extracts produced with ethanol or other solvents, showing solvents have been driven off below safety thresholds).
Identity Confirmation
This is often skipped but it's critically important: confirmation that the species in the product is actually what's on the label. DNA barcoding or HPLC fingerprint matching against a reference sample is the gold standard. Cheaper brands often skip this, and there have been multiple industry studies finding wrong species in significant percentages of products.
Our COAs on the Certificate of Analysis page include identity confirmation for every batch.
What Marketing Tricks to Watch For
The supplement industry has gotten creative. Watch for:
- "Tested for purity" with no lab name or methodology. Meaningless.
- "Third-party tested" without a publicly available report. Possibly meaningful, but you can't verify.
- "Polysaccharides: 30%" on a product that uses grain-substrate mycelium. The 30% may be largely substrate starch, not active mushroom compounds.
- Cherry-picked COAs from one batch. Reputable brands publish recent COAs for every batch. The same one-year-old COA on the website for years is a flag.
Where to Practice
The best way to build COA-reading skill is to actually read some. Our COA page has every batch for every product we make — Lion's Mane, Reishi, Cordyceps, Kava, Kanna, and Yerba Mate. Open three. Compare them. Notice the consistency of the methodology.
Once you've read ours, read one from a brand you're considering. The contrast tells you everything.
Where to Start
For products tested batch-by-batch with full transparency, browse the full Mushroom Alchemy catalog. Every product links to its current batch COA from the product page.
If a brand can't show you the receipt, they don't have the receipt.