What microbial tests are run on kratom and 7-OH products?

The standard panel measures total aerobic microbial count (TAMC) and total yeast and mold count (TYMC), and confirms the absence of Escherichia coli and Salmonella. Some product categories add additional pathogens.

What method is used for microbial testing?

Enumeration is typically performed by plate count or membrane filtration following USP . Tests for specified pathogens use selective enrichment and plating on selective media following USP .

Total Aerobic Microbial Count - the total number of viable aerobic bacteria per gram of sample. It is reported as colony-forming units per gram (CFU/g).

Total Yeast and Mold Count - the total number of viable yeast and mold colonies per gram of sample. Like TAMC, it is reported as CFU/g.

Why are botanical products at risk for microbial contamination?

Botanicals are agricultural products: they are exposed to environmental microorganisms during cultivation, harvest, drying, milling, and packaging. Without controlled processing, microbial counts can exceed acceptance limits.

What does 'pass' mean for microbial testing?

It means TAMC and TYMC are below the applicable USP acceptance limit and that the specified pathogens (E. coli, Salmonella) are absent in the test sample mass. The COA should disclose both the measured values and the limits.

Lab Testing & Quality

Microbial Testing

At-a-glance comparison

Spec	Value
Standard panel for botanicals	Total Aerobic Microbial Count (TAMC); Total Yeast and Mold Count (TYMC); absence of E. coli; absence of Salmonella
Standards reference	USP <2021> Microbial Enumeration Tests; USP <2022> Tests for Specified Microorganisms
Methodology	Plate count or membrane filtration for enumeration; selective enrichment for specified pathogens
Why it matters for kratom	Botanical products are inherently susceptible to microbial contamination from agricultural sources, post-harvest handling, and processing
Typical units	Colony-forming units per gram (CFU/g)
Where results appear	On every reputable kratom and 7-OH product Certificate of Analysis

What is microbial testing?

Microbial testing is the laboratory analysis of a product for the presence and quantity of microorganisms. For dietary supplements and botanical products, including kratom and 7-hydroxymitragynine products, microbial testing is a standard release test that measures the level of total bacterial and fungal contamination and confirms the absence of specific pathogens.

The standard panel for botanical products consists of two enumeration tests - total aerobic microbial count (TAMC) and total yeast and mold count (TYMC) - and two qualitative tests for specified pathogens - Escherichia coli and Salmonella. Some product categories add additional pathogens such as Staphylococcus aureus or bile-tolerant Gram-negative bacteria; the specific panel depends on the regulatory framework and the product type.

How microbial testing is performed?

The standard methodology is described in United States Pharmacopeia chapters Microbial Enumeration Tests and Tests for Specified Microorganisms. Enumeration is typically performed by plate count: a known mass of sample is suspended, serially diluted, plated on selective media, and incubated under defined conditions; the resulting colonies are counted to give colony-forming units per gram (CFU/g). Membrane filtration is used for samples whose composition would interfere with direct plating.

Tests for specified pathogens use selective enrichment in a non-selective medium followed by plating on selective media. The presence or absence of characteristic colonies is determined by colony morphology and confirmed by biochemical or molecular testing. The results are reported as "absent" or "present" in a defined sample mass (typically 10 grams for E. coli and 25 grams for Salmonella).

Acceptance criteria

United States Pharmacopeia chapter specifies microbial acceptance criteria for non-sterile dietary supplements. Acceptance criteria for TAMC and TYMC vary by the dosage form (powder, tablet, etc.) and the intended route of exposure. Specified pathogens (E. coli, Salmonella) are required to be absent in the test sample masses defined above.

The American Kratom Association GMP Standards Program specifies kratom-specific microbial test panels and acceptance criteria for member vendors. Compliance with these criteria is determined by comparing the measured CFU/g against the applicable limit and confirming pathogen absence.

Common questions about microbial testing

What microbial tests are run on kratom and 7-OH products?: The standard panel measures total aerobic microbial count (TAMC) and total yeast and mold count (TYMC), and confirms the absence of Escherichia coli and Salmonella. Some product categories add additional pathogens.
What method is used for microbial testing?: Enumeration is typically performed by plate count or membrane filtration following USP . Tests for specified pathogens use selective enrichment and plating on selective media following USP .
What is TAMC?: Total Aerobic Microbial Count - the total number of viable aerobic bacteria per gram of sample. It is reported as colony-forming units per gram (CFU/g).
What is TYMC?: Total Yeast and Mold Count - the total number of viable yeast and mold colonies per gram of sample. Like TAMC, it is reported as CFU/g.
Why are botanical products at risk for microbial contamination?: Botanicals are agricultural products: they are exposed to environmental microorganisms during cultivation, harvest, drying, milling, and packaging. Without controlled processing, microbial counts can exceed acceptance limits.
What does 'pass' mean for microbial testing?: It means TAMC and TYMC are below the applicable USP acceptance limit and that the specified pathogens (E. coli, Salmonella) are absent in the test sample mass. The COA should disclose both the measured values and the limits.

References

United States Pharmacopeia. (2024). General Chapters , , .
American Kratom Association. AKA GMP Standards Program. https://www.americankratom.org/aka-gmp-program

Important safety information:

Products containing 7-hydroxymitragynine (7-OH) are sold for adult use only (21+). These statements have not been evaluated by the U.S. Food and Drug Administration. Products are not intended to diagnose, treat, cure, or prevent any disease. The FDA has raised safety concerns regarding concentrated 7-OH products; consult a qualified healthcare professional before use. Do not operate vehicles or machinery after use. Keep out of reach of children and pets. Laws vary by state, buyers are responsible for knowing applicable law.