Beyond THC Numbers: Cannabis Lab Testing in Thailand and How to Read a COA
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For dispensary owners, cannabis lab testing in Thailand should be treated as a buying tool, not a decorative certificate. A Certificate of Analysis, usually called a COA, can help a retailer check what was tested, which batch the result belongs to, when the sample was analysed and whether the report covers more than cannabinoid percentages. Used properly, it can expose missing information before stock reaches the shelf. Used badly, it becomes little more than a PDF attached to a sales message.
In 2026, Thailand’s medical cannabis market is becoming more structured around traceability, documented quality and professional supply. Current DTAM guidance states that cannabis flower intended for sale must be supported through recognised cultivation standards or a product-quality COA from a private laboratory. That makes the ability to read testing documents increasingly important for cultivators, distributors and dispensaries.
At OG Distribution, we prioritise products supported by appropriate documentation where applicable. However, a retailer should never accept a COA simply because a supplier says one exists. The document must be current, relevant and clearly connected to the stock being offered.
What Is a Cannabis COA?
A COA is a laboratory report showing the results obtained from testing a specific sample. Depending on the requested panel, it may include cannabinoid potency, microorganisms, pesticides, heavy metals, moisture-related measurements or other quality indicators.
The most important words are specific sample.
A COA does not automatically prove that every gram ever produced by a farm has exactly the same composition. It reports what the laboratory found in the material submitted for testing. Batch details, sample dates and product identification therefore matter just as much as the final THC figure.
A useful COA should answer five basic questions:
- Which product or batch was tested?
- Who tested it?
- When was it tested?
- Which analyses were performed?
- What were the results?
When any of those answers is missing, the report needs closer examination.
Match the Report to the Actual Batch
One of the most important parts of cannabis lab testing in Thailand is traceability.
The COA should identify the sample using details such as the cultivar name, batch or lot number, sample code, supplier, harvest date or submission date. The batch number on the report should match the batch being offered to the dispensary.
A supplier may show a genuine COA for a popular strain, but that does not prove the current delivery came from the tested batch. Two harvests sold under the same cultivar name can differ because of growing conditions, harvest timing, drying, curing and storage.
For a meaningful wholesale purchase, the retailer should request the matching document before accepting delivery—not after a customer questions the product.
Check the Laboratory Before the THC Number
Many buyers open a COA and immediately search for the largest percentage. A better first step is checking who produced the report.
Look for:
- The laboratory’s legal name and contact details
- A report or certificate number
- Dates received, tested and reported
- The analytical methods used
- An authorised signature or digital verification
- Accreditation information
ISO/IEC 17025 is the international standard used to assess the competence, impartiality and consistent operation of testing and calibration laboratories. Accreditation adds confidence, but it normally applies to a defined scope. A laboratory may be accredited for some methods and not others, so buyers should check whether the relevant cannabis analysis is included.
A polished logo or the words “certified laboratory” are not enough. For a large order, verify the laboratory independently rather than relying only on information printed on the report.
Understanding the Cannabinoid Panel
The cannabinoid section may list THC, THCA, CBD, CBDA, CBG, CBN and calculated totals.
THCA and CBDA are acidic cannabinoids found naturally in raw flower. Heat converts part of them into THC and CBD. This is why “total THC” is normally calculated rather than copied directly from the THC line.
Retailers should also check the units. Results may be presented as a percentage, milligrams per gram or on a dry-weight basis. Two reports should not be compared until the units and calculation methods are understood.
A high potency figure is not a complete quality score. It cannot prove:
- Good cultivation
- Clean handling
- Correct moisture
- Strong aroma
- Proper curing
- Freedom from contaminants
A 30% result should not automatically be treated as superior to a lower result. Potency is one part of the product profile, not a verdict on the whole flower.
What Do ND, LOD and LOQ Mean?
COAs often contain abbreviations that can easily be misunderstood.
ND usually means “not detected.” It does not always mean the substance is absolutely absent; it may mean the amount was below the method’s ability to detect it.
LOD, or limit of detection, is the lowest level at which the method can identify that something may be present.
LOQ, or limit of quantification, is the lowest level at which the laboratory can reliably report how much is present.
“Not detected” is therefore not always identical to zero, and “below LOQ” does not necessarily mean nothing was found. The report notes should explain how the laboratory uses these terms.
A Potency Test Is Not a Full Safety Panel
A report showing only THC and CBD is not the same as broad contaminant testing.
Depending on the product and requested panel, a COA may also examine:
Microorganisms
Testing may cover yeast, mould, E. coli, Salmonella or other microorganisms. Flower is an agricultural material, so poor drying, humid storage or contaminated handling can create problems after harvest.
Pesticides
A pesticide screen checks for a defined list of chemical residues. Retailers should ask which compounds were included rather than accepting the vague phrase “pesticide tested.”
Heavy Metals
Cannabis can take up substances from soil, water and nutrients. Common panels may examine lead, arsenic, cadmium and mercury. Thai FDA materials recognise testing for THC, CBD and potentially harmful contaminants, including heavy metals, within relevant cannabis-control frameworks.
Mycotoxins
Certain moulds can produce harmful mycotoxins. These may be tested separately from the broader microbial panel.
Residual Solvents
This is mainly relevant to extracts and manufactured concentrates. When solvents have been used during production, a specific panel may check whether residues remain.
The phrase “full panel” does not have one universal meaning. Buyers should always ask for the actual list of analytes and the standards used to determine a pass or failure.
GACP and a COA Are Not the Same Thing
GACP and COA are frequently mentioned together, but they provide different types of evidence.
GACP—Good Agricultural and Collection Practices—relates to the systems used to cultivate, harvest and handle medicinal plants.
A COA reports laboratory findings for a submitted sample or batch.
GACP can show that a farm works within a structured cultivation system. A COA can show what an analytical laboratory found in specific material. One evaluates the production framework; the other provides test data.
Current DTAM guidance states that cannabis flower from a cultivation site seeking permission for sale must have recognised certification through GACP assessment or a cannabis or hemp product-quality COA from a private laboratory.
For dispensaries, the strongest supply relationship is not based on one impressive certificate. It is built from documents, batch records, cultivation information and a physical product that all support the same story.
Red Flags Buyers Should Notice
Retailers should pause when:
- The batch number is missing
- The product name does not match the stock
- The report is unusually old
- The laboratory cannot be verified
- Pages appear cropped or edited
- Only potency was tested, but the supplier claims a complete safety panel
- Units or methods are unclear
- Every batch is presented with identical results
- A QR code does not work
- The supplier refuses to provide the complete report
These points do not automatically prove fraud, but they require a satisfactory explanation before money changes hands.
A screenshot is also easier to alter than a complete laboratory file. Ask for the original PDF or a verifiable online record whenever possible.
Why the Testing Date Still Matters
Cannabis can change after laboratory analysis.
Heat, oxygen, light, time and poor storage may affect flower after the sample was tested. A genuine report from harvest does not prove that badly stored stock remains in the same condition months later.
The testing date should be considered alongside:
- Harvest and packaging dates
- Storage conditions
- Transport time
- Seal condition
- Current aroma, texture and appearance
This is particularly relevant in Thailand’s hot and humid climate. A COA supports a purchasing decision, but it does not replace checking the delivered product.
How OG Distribution Approaches Testing Documents
OG Distribution supplies retail-ready products to licensed dispensaries and businesses across Thailand. Our wholesale information states that we prioritise quality, consistency and supporting documentation such as COAs where applicable.
We believe documentation should be part of the product conversation from the beginning. Useful questions include:
- Which batch does the report cover?
- Which testing panel was ordered?
- Can the laboratory be verified?
- Are the results current?
- Does the delivered stock match the paperwork?
- Is further documentation available where applicable?
Because we work across cultivation, manufacturing, brand development and nationwide distribution, we understand that quality information must move with the product through the supply chain.
Our role is not to tell dispensaries that every certificate proves perfection. It is to help licensed partners source retail-ready products with clearer provenance, appropriate records and more reliable information than unsupported sales claims.
A Practical COA Checklist
Before accepting wholesale flower, check:
- Laboratory name and credentials
- Report number
- Product and batch identity
- Sample and testing dates
- Cannabinoid units and calculation method
- Contaminant panels included
- Pass or fail limits
- ND, LOD and LOQ definitions
- Signature or digital verification
- Match between the COA and delivered stock
Keep the report with the purchasing and batch records. When stock is divided between branches, each location should be able to identify the batch it received.
Final Thoughts
Good cannabis lab testing in Thailand is not about chasing the highest THC result or collecting certificates that nobody reads. It is about connecting a real laboratory report to a real batch, understanding which tests were performed and spotting gaps before they become retail problems. For dispensaries, the strongest buying decisions combine laboratory data, traceable supply, correct storage and a supplier willing to answer detailed questions. OG Distribution works with licensed partners across Thailand to provide retail-ready products and appropriate supporting documentation where applicable, helping stores choose stock on evidence rather than sales claims.