How to Read a Certificate of Analysis for Oregano Oil (And What to Look For)
How to Read a Certificate of Analysis for Oregano Oil (And What to Look For)
Most supplement buyers have heard the words third-party tested. Far fewer know what to do with the actual document when they find it. A certificate of analysis is a one-page report that either backs up what a brand claims or quietly exposes where it cuts corners.
Almost everyone in the supplement space knows a CoA exists. Very few buyers know what the columns actually mean, which is exactly the gap brands are counting on. A certificate of analysis is not marketing material. It is a technical document, and reading it takes about sixty seconds once you know which rows to look at.
Here are the five rows that matter, in plain language, so you know what you are actually holding when you pull up a brand's test results.
1. The carvacrol row: the single most important number on the page
Carvacrol is the active phenolic compound in oregano oil responsible for its potency. Every quality CoA will show a percentage: the higher the number, the more of the active compound is present per dose. A formula sitting at 85 percent carvacrol delivers more of the working compound per softgel than one at 50 percent.
When a brand does not print its carvacrol level anywhere, check the CoA. If the carvacrol row is blank, unlabeled, or absent entirely, treat that as an answer. A brand confident in its potency does not hide the number.
2. The identity confirmation: are you getting Origanum vulgare?
Not all oregano is the same species, and not all species carry the same carvacrol profile. The identity row on a CoA should confirm Origanum vulgare, the Mediterranean botanical traditionally prized for its carvacrol content. Wild-harvested Greek oregano scores higher than many cultivated alternatives.
A CoA that simply says oregano without botanical confirmation is leaving the door open. The identity row should read Origanum vulgare or list a voucher specimen reference to the source material.
👉 Want to see a CoA that prints all five rows in plain numbers? See 85% Carvacrol Oil of Oregano →
3. Heavy metals: what the limits mean in plain language
A complete CoA reports on lead, arsenic, mercury, and cadmium. Each metal has a maximum limit expressed in parts per million (ppm) or micrograms per gram. Passing means the measured value falls below that limit, not that the metal is absent entirely.
For a dietary supplement, the accepted passing threshold for lead is typically under 0.5 ppm. The CoA should show both the method detection limit and the actual measured result for each metal. If the results section is blank or shows only a pass/fail checkmark without numbers, that is less useful than a CoA that shows the actual measurement.
4. Microbial testing: why it matters more than most buyers realize
The microbial panel covers total aerobic plate count, yeast, mold, E. coli, and Salmonella. Botanical concentrates can carry microbial load from the plant material itself, which is why this row matters even for an oil-based supplement.
Passing results show colony-forming units (CFU) per gram within the USP or NF standard for dietary supplements. A clean result on yeast and mold in particular tells you the material was handled properly from harvest through encapsulation.
5. Who issued the test: the difference between in-house and independent labs
The issuing lab row is where a CoA reveals whether the result is independently verified or simply self-reported. An in-house test conducted by the brand's own facility is not the same as one issued by an accredited third-party lab.
Look for ISO 17025 accreditation on the lab header, or a recognized third-party lab name such as Eurofins, Covance, or NSF. When we pulled our own CoA and ran through this checklist, the 85% carvacrol row on Hyams Oil of Oregano was printed in plain numbers, issued by an independent third-party lab.
Hyams Oil of Oregano: 85% carvacrol, third-party verified, five rows clean
We built this checklist first, then held it up against our own formula. Hyams Oil of Oregano posts its certificate of analysis results for carvacrol concentration, botanical identity (Origanum vulgare, wild-harvested), heavy metals, microbial counts, and independent lab issuance.
- 85% carvacrol, verified on CoA
- Origanum vulgare wild-harvested identity confirmed
- Heavy metals below threshold
- Microbial counts within range
- Third-party independent lab tested
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Frequently asked
A certificate of analysis (CoA) is a document issued by a testing lab that reports the measured results of a supplement against its specifications. For oregano oil, the key rows include carvacrol percentage, botanical identity, heavy metals, and microbial counts.
The higher the carvacrol percentage, the more of the active compound per dose. Many products sit around 50 to 60 percent. A high-quality oregano oil formula will state its carvacrol level clearly; 85 percent is toward the upper end of what commercially available oregano oil reaches.
Independent lab testing does add a cost, but reputable brands absorb it. An accredited third-party lab result means the brand did not simply issue its own passing grade.
Many brands post CoA results directly on their website or on a product page. If one is not visible, you can contact the brand and request the most recent batch CoA. A brand with nothing to hide will share it.
Five rows. One number that matters most. Now you know what to look for.
The carvacrol row, the identity confirmation, the heavy metals panel, the microbial results, and the issuing lab. That is the whole checklist.
See Hyams Oil of Oregano →Third-party tested. 85% carvacrol.