A Certificate of Analysis is the single document that proves your batch is what the label says it is. Most brand owners file it, never read it, and lose the chance to catch a quality issue before it hits a customer. Here’s how to actually read one.
What a CoA is, and isn’t
A Certificate of Analysis is a record of measured values from QC testing, compared against the specification for that product. It’s a snapshot of one specific batch, not a generic claim about your product family.
Every batch we ship has its own CoA, identified by batch number, manufacturing date, and expiry date.
The anatomy of a proper CoA
Header section, identity
- Product name, matches your label
- Batch / lot number, this is the unique key for traceability
- Manufacturing date and expiry / best-before date
- Quantity manufactured, e.g., 5,000 bottles
- Manufacturer name and registration, ours: Pharm Scale d.o.o., FDA Reg. 14287957814
Specification table, the meat
This is what you should actually read. Each row has three columns:
- Parameter, what was tested (e.g., “Vitamin D3 assay”)
- Specification, what the result should be (e.g., “≥ 90% of label claim”)
- Result, what was actually measured (e.g., “98.2%”)
The 8 lines you should always check
1. Identity test result
Method: HPLC, FTIR, or similar. The result should explicitly confirm the active is what the label says. “Conforms” is acceptable; “passes” is not specific enough, ask what was tested.
2. Active assay result
Should be within ±10% of label claim for most actives. Some thermolabile vitamins (B1, C) need a higher overage during manufacturing because they degrade over shelf life.
3. Disintegration / dissolution time
For solid dose forms only. Capsules should disintegrate in <30 minutes in simulated gastric fluid. If it’s longer, the active won’t release on time.
4. Microbiological, total aerobic count
Look for “< X CFU/g” against the spec. CFU = Colony-Forming Units. Different product types have different limits (botanical ingredients are allowed more than synthetic vitamins).
5. Microbiological, pathogens
E. coli, Salmonella, S. aureus, Pseudomonas. Should ALL read “absent in 1g (or 25g for water-activity foods)”. Anything else is a fail.
6. Heavy metals, lead, cadmium, mercury, arsenic
Look for the actual measured value vs the spec, not just “compliant”. A good CoA shows: “Lead: 0.05 mg/kg (spec: < 0.1 mg/kg)”. A poor one says only “compliant”.
7. Moisture content / water activity
For powders, gummies, and uncoated tablets, this matters for shelf life. Should be within product-specific limits (typically < 5% for powders).
8. Visual / organoleptic
Color, odor, appearance match the reference standard. Sounds soft, it isn’t. Visible discoloration in a finished product is a degradation signal.
Red flags to watch for
- “Compliant” without measured values, the manufacturer didn’t share the actual numbers, ask why
- Missing test parameters, if they’re not testing for heavy metals on a botanical product, you have a problem
- “Estimated shelf life” without stability data, supplier hasn’t actually tested it
- The same CoA being shipped against multiple batches, major audit failure
- Active assay at <90% of label claim, either underdosed or degraded
What to do with the CoA
- File it. Keep it for the entire shelf life of the batch + 1 year. Required by FDA Part 111 and EU good practice.
- Share it. Retailers, especially Amazon, Walmart, big EU pharmacies, will ask for a CoA before listing.
- Use it. If a customer complains about a specific batch, the CoA tells you whether the product was within spec when it left the facility.