How to Read a Certificate of Analysis (COA)

How to Read a Certificate of Analysis: Overview

Every hemp distributor must get one. It’s a technical document that should be included with every CBD purchase— essentially a nutritional fact sheet for your hemp. 

But how in the hell do you read a certificate of analysis? 

In this post, we’ll answer that question and touch upon a few more like, 

  • What’s a certificate of analysis?
  • Where do you get a certificate of analysis?
  • How do you read a certificate of analysis?
  • How do you understand cannabinoids, heavy metals, and pesticide analyses?
  • What should you do if there’s something wrong with your certificate of analysis?

What’s a Certificate of Analysis?

A certificate of analysis, COA for short, is a document from an accredited third-party lab that shows you what’s in your CBD product. Think about them as the hemp equivalent of a nutritional fact sheet on the back of any food product. 

Certificates of Analysis are important because: 

  • They ensure that your product contains advertised levels of CBD.
    • Some studies have found that nearly 7 out of 10 hemp products do not contain the advertised level of CBD. 
  • They indicate whether or not the product in question is legally hemp or a federally-prohibited cannabis product.
    • Products with over 0.3% of delta-9 THC by dry weight are considered to be THC cannabis. 
  • Depending on how your product is advertised— full-spectrum, broad-spectrum, THC-free, etc.— the presence of additional cannabinoids may raise an eyebrow. 

Read more about the differences between full-spectrum, broad-spectrum, and isolate here.

Where Do You Get a Certificate of Analysis?

When you read a certificate of analysis, be sure to look for the lab that produced it. Vendors should always have their products tested at accredited third-party laboratories. 


Imagine you’re buying a used car. Many of us aren’t mechanics; we can look at the exterior and even look underneath for obvious problems, but would you really buy a car without getting the carfax or having your mechanic take a look under the hood? Probably not. 

The same goes for CBD vendors. They’re probably telling the truth about their products, but every vendor should readily provide you with test results from a neutral third party. Many eCommerce vendors will host their COAs somewhere on their website. Sunset Lake CBD’s certificates of analysis can all be found under the Quality Test tab in the main header menu.

How to Read a Certificate of Analysis Lab Test

From the Top, Of Course!

Top of 3,000mg CBD Oil Tincture Certificate of Analysis
From our Full Spectrum 3,000mg CBD Oil Tincture (C21012AH)

Who conducted the test?

Bia Diagnostics Laboratories. On this particular certificate of analysis, the lab’s contact information is to the right of the name. That might not always be the case. Underneath the lab’s name, we see:  

  • The unique identification number assigned to the sample – C21012AH
  • The name of the sample – 3000 mg tincture (60mL)
  • And, what type of product this sample is – Oil

Who’s getting the test?

That’d be us, Sunset Lake CBD (Sunset Lake Enterprises.) Under our name, we see our incorporation address (street address omitted.) Our Vermont Hemp Program grower’s license number is also listed at the bottom of the first column.

How to Read Your Certificate of Analysis: Cannabinoid Profile

Now we’ve hit the meat of the certificate of analysis. What cannabinoids are in your product and in what concentration? Below is the cannabinoid summary of our 3,000mg CBD Oil Tincture.

3,000 mg CBD Oil Tincture Cannabinoid Profile

How to Read Your Certificate of Analysis: CBD

Wait… what gives? You buy a CBD tincture advertised at 3,000mg and your certificate of analysis says that there’s only 4.79%

Both can be true. Let’s take a look at the “Concentration mg/g” column. Our 3000mg tincture has 47.87mg/g of oil. To get our total mg per bottle we need to do a little math. 

MCT oil, our carrier oil weighs nearly 1 gram/mL. Our 3,000mg tinctures contain 60mL meaning that they also weigh just about 60 grams. We need to take that number and multiply it by our 47.87mg/g CBD concentration to get 2,872.2mg total; well within the 10% margin of error. 

These calculations will apply to most other oil, topical, and edible products too.

How to Read Your Certificate of Analysis: CBD Flower

This calculation can be a bit different when looking at your CBD Flower certificate of analysis. Let’s take a look at our 2019 Hawaiian Haze flower cannabinoid report from ProVerde Labs:

Cannabinoid Report for 2019 Hawaiian Haze CBD Flower

This flower was advertised as containing ~ 15% and your certificate of analysis says that there’s only 0.15% CBD present. What gives? 

Let’s talk about CBDa and conversions, shall we? CBDa, short for cannabidiolic acid, is the precursor to CBD and is mainly found in raw forms of cannabis. When it’s heated, exposed to light, or ignited, CBDa will convert to CBD via a process called decarboxylation; wherein CBDA will drop an extra carboxyl ring. 

Accounting for a loss of mass (the lost carboxyl ring) during conversion, this certificate of analysis suggests that our Hawaiian Haze flower will contain 15.68% total CBD post-decarboxylation.

How to Read Your Certificate of Analysis: THC

Delta9-THC (Δ9 tetrahydrocannabinol) – This is the phytocannabinoid that will get you “high,” and the only cannabinoid specifically restricted in the 2018 Federal Farm Bill. According to the feds (and most states), cannabis is only considered to be hemp if D9-THC makes up less than 0.3% of the sample by dry weight. 

THCa (tetrahydrocannabonic acid) – Tetrahydrocannabonic acid, like CBDa is to CBD, is the precursor to delta9-THC. It is not counted against a CBD product when determining legality though.

How to Read Your Certificate of Analysis: Minor Cannabinoids

THCV (tetrahydrocannabivarin) – Similar to THC in molecular structure sans a few carbon chains. 

CBDV (cannabidivarin) – Similar to CBD in chemical makeup. Like THCV, this phytocannabinoid is still largely unresearched. But early studies are suggesting that this could help with a number of maladies. 

CBG (cannabigerol) – A genetic precursor to both CBD and D9-THC. Think of it as almost a cannabinoid stem cell. 

CBC (cannabichromine) – Considered one of the “big six” cannabinoids prominent in medical research. CBC isn’t intoxicating, but there is research into this phytocannabinoid’s medicinal benefits. 

CBN (cannabinol) – Think of cannabinol as THC in old age. As time passes, THC degrades into the non-intoxicating CBN. 

CBGa (cannabegeriolic acid) – The acidic form of CBG. 

D8-THC (Δ8 tetrahydrocannabinol) – Chemically different from D9-THC, but still intoxicating.

exo-THC (exo-tetrahydrocannabinol) – Exo THC is an impurity formed during the synthesis of D9-THC.

How to Read Your Certificate of Analysis: Weights and Concentrations

Let’s see that 2019 Hawaiian Haze Flower cannabinoid profile again, shall we?

Cannabinoid Report for 2019 Hawaiian Haze CBD Flower
2019 Hawaiian Haze Hemp Flower Cannabinoid Profile

In the weight column, we see what share (%) of the Hawaiian Haze flower sample is each cannabinoid. For example, CBDa made up 17.7% of the flower sample’s dry weight. 

Concentration is a similar measurement. Instead of considering the whole sample of flower, we can boil it down to if we had one gram of flower, how many milligrams of that cannabinoid would be present. In the case of d9-THC, in one gram of flower, there are 0.15 milligrams of d9-THC. 

You can also use concentration to calculate the potential CBD mg total in your hemp flower. For example, if you buy 3.5 grams of Hawaiian Haze flower, you can multiply the weight by the total CBD for: 

3.5 g x 156.78 mg/g CBD = 548.73 mg

How to Read Your Certificate of Analysis: Pesticides and Heavy Metals?

Most certificates of analysis end with cannabinoid reports. Some, more in-depth, certificates of analysis can include heavy metal, fungi, and pesticide reports.

Important definitions: 

  • Conc. – Concentration. 
  • µg – Microgram (.000001 gram)
  • Ppb – parts per billion
  • MDL – Method detection level – the minimum concentration of that substance that can be measured and reported with 99% confidence. 
  • ND – Not detected to the lowest limit of detection. 

Below is the heavy metal analysis of our 2019 Hawaiian Haze flower analysis.

2019 Hawaiian Haze CBD Flower Heavy Metal Test
2019 Hawaiian Haze Hemp Flower Heavy Metals Analysis

Reading the Heavy Metal Analysis

There are really three columns in this section of our certificate of analysis we want to take a look at on the heavy metals test:

Conc. tells us how many micrograms of that heavy metal are in each kilogram of our 2019 Hawaiian Haze hemp flower. 

MDL tells us how sensitive the test is. For example, if our flower had less than 9 micrograms of Arsenic per kilogram, the Conc. column would read “<MDL” mean undetectable amounts. Our flower contains traces that exceed the MDL  but test well under the established limits. 

Status tells us whether or not the flower passes the test.  We pass with flying colors.  

Reading the Pesticide Analysis 

Last, but certainly not least, we come to the pesticide analysis portion. Most simple certificates of analysis won’t contain one of these either, but more in-depth full panel tests will. If you’d like your hemp vendor to produce full-panel results, just ask!

More important definitions:

  • Ppb – Parts per billion
  • LLD – Lower limit of detection
2019 Hawaiian Haze CBD Flower Pesticide Analysis
2019 Hawaiian Haze Hemp Flower Pesticide Analysis

Much like the heavy metals testing, this table tells us the lowest amount of each pesticide that the lab can pick up (LLD,) while also telling us the upper limit of acceptable consumption. 

All of Sunset Lake CBD’s hemp flower is pesticide-free, hence the full column of nondetectable’s in the “Result” column.

What to Do if There Is a Problem With Your Certificate of Analysis

There are a few instances where you should make a stink about your certificate of analysis. 

You didn’t get a certificate of analysis 

This is a big red flag. Every CBD hemp vendor is required to include a certificate of analysis. Without the proper documentation, there’s no way for you to verify what’s in your product. There’s also no paperwork to show authorities should your CBD be mistaken for marijuana. 

Your certificate of analysis doesn’t match the product you received 

Do the strain names match? How about the identification number? If not that could be a problem. Check the company’s website for the correct paperwork. If it’s not present, you could and should request the correct certificate of analysis before placing an order. If they’re worth their salt, they should provide it free of cost and ASAP. 

Your certificate of analysis isn’t from a third-party lab 

Getting a certificate of analysis is better than nothing at all. But unless you trust the company, don’t be afraid to reach out to the vendor and ask for third-party results

If you ever have any questions about our COA’s PLEASE reach out to us. If you’re looking for more information in general or on other companies’ COA’s we would be happy to either help you out or provide you with more resources.

Updated August 5, 2021


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