How to Read a Kratom Lab Test (COA): What Every Buyer Should Know
A kratom lab test, aka a certificate of analysis (COA) is your most reliable tool for evaluating what you’re actually buying. Unlike marketing claims or vendor testimonials, a COA is data. It tells you the alkaloid profile, contaminant levels, and microbial status of a specific batch. But only if you know how to read it.
Most kratom buyers ignore COAs entirely. Others glance at them and have no idea what the numbers mean. Vendors exploit both gaps—some hide their testing results, others publish them without explanation. The ones worth buying from make testing transparent and answer your questions about the data.
This guide walks you through every section of a kratom COA, what the numbers actually mean, and how to spot vendors hiding problems behind jargon or missing data.
Core Components of a Kratom COA
A complete kratom COA covers five main categories: alkaloid profile, heavy metals, microbial contaminants, moisture content, and water activity. A reputable lab tests all of these. If a vendor’s COA is missing any section, ask why.
Alkaloid Content
The alkaloid profile is what most buyers focus on first. Kratom’s primary alkaloids are mitragynine and 7-hydroxymitragynine (7-OH). You’ll see these reported as a percentage of the total product weight.
Mitragynine typically ranges from 0.5% to 1.5% in raw leaf powder. Seven-OH is usually much lower, often between 0.01% and 0.1%. Mitragynine explained – the dominant alkaloid in kratom – is measured as a percentage of product weight. Consistency matters across batches: a batch that falls far below the vendor’s stated range suggests poor handling, storage, or harvest timing.
A COA should also list secondary alkaloids: speciosphylline, paynantheine, and others. These contribute to the overall alkaloid profile and help you compare consistency across batches from the same vendor.
Heavy Metals Testing
Heavy metals testing checks for lead, cadmium, arsenic, and mercury. These are naturally present in soil and can accumulate in plants, including kratom. The key metric here is ppm (parts per million) or mg/kg (milligrams per kilogram—equivalent to ppm).
Current industry standards suggest thresholds around:
- Lead: <5 ppm
- Cadmium: <1 ppm
- Arsenic: <2 ppm
- Mercury: <0.2 ppm
These are not legally binding limits for kratom in the U.S., but they align with FDA guidance for dietary supplements. If a COA shows detectable levels of any heavy metal, the vendor should explain the context. Low-level detection isn’t necessarily a dealbreaker, but “ND” (non-detectable) is what you’re looking for.
Microbial & Bacterial Analysis
This section tests for harmful bacteria like E. coli, salmonella, and listeria. The COA will report either “ND” (non-detectable) or a count in colony-forming units (CFU). For food and supplement products, ND is the standard you expect.
Some labs also test for yeast and mold. Kratom powders can absorb moisture during storage, creating conditions for mold growth. A reputable vendor controls storage conditions and tests regularly to catch this.
Moisture & Water Activity
Moisture content and water activity (aw) measure how much water is in the product. Kratom powder should typically have moisture content below 12% and water activity below 0.65 aw. These numbers indicate proper drying and storage. High moisture creates risk for bacterial and mold growth.
How to Read the Numbers
Numbers mean nothing without context. Here’s how to interpret the data on a real COA.
Understanding Alkaloid Percentages
A COA might show mitragynine at 1.2% and 7-OH at 0.08%. These percentages tell you the concentration by weight. If you’re taking a 5-gram serving, you’re consuming roughly 60 mg of mitragynine.
Compare this across batches and vendors. If one vendor’s green vein consistently tests at 1.0% mitragynine and another’s at 0.6%, the difference is measurable. Consistency matters—vendors who control their supply chain have more consistent testing results.
Also check the testing date. A COA from nine months ago may not reflect the current batch. Ask vendors how often they test and whether recent results are available.
Interpreting Contaminant Test Results (ppm, mg/kg, “ND”)
“ND” means non-detectable—the contaminant is below the lab’s detection limit. This is what you want to see for microbial (E. coli, salmonella) and ideally for heavy metals too.
When a report shows a number (e.g., “Lead: 2.3 ppm”), that’s detectable contamination. Low levels aren’t uncommon in plant material, but transparency matters. A vendor should be able to explain where the contamination came from and what steps they take to minimize it in future batches.
Watch for reports that list heavy metals with no threshold context. A vendor showing “Arsenic: 1.2 ppm” without noting the industry threshold looks like they’re hiding. Compare their results to other vendors and ask questions.
Red Flags to Watch For
Not all COAs are equal. Here’s what to watch for:
Missing sections. If a COA omits heavy metals, microbial testing, or moisture content, that’s a red flag. Ask why before buying.
Suspiciously high alkaloids. Mitragynine above 2.0% is uncommon in legitimate raw leaf powder. If a vendor’s alkaloid profile is consistently in the 1.8–2.5% range, verify the lab’s methodology. Some labs measure alkaloids differently, but massive outliers suggest poor quality control or inaccurate testing.
Detectable contaminants without explanation. A report showing E. coli, salmonella, or high heavy metal levels with no vendor comment is concerning. Legitimate vendors explain batch contamination and corrective actions.
Outdated testing. A COA dated six months or a year ago doesn’t reflect your current order. Reputable vendors test every batch or every few batches. Ask when the product you’re buying was last tested.
Labs without accreditation. Look for mention of ISO 17025 or AOAC (Association of Official Analytical Chemists) accreditation. These standards mean the lab’s methods are validated and results are reliable. If a vendor won’t name their lab or the lab has no recognizable credentials, move on.
How to Use COA Data to Evaluate Vendors
A COA tells you more than just numbers. It reveals how serious a vendor is about quality.
Transparency indicators. Vendors who publish COAs prominently, make them easy to find, and link them directly to products are prioritizing transparency. Some vendors hide COAs behind email requests or publish generic “typical analysis” without batch-specific data. The first type is worth dealing with.
Consistency across batches. Download COAs from a vendor across different months. Do the alkaloid ranges stay consistent? Do contaminants stay ND? Vendors with tight control over sourcing and processing show less variation.
Lab quality and accreditation. A vendor using the same accredited lab repeatedly signals commitment to quality. If every product has a COA from a different lab, that’s a yellow flag. Reputable labs like Ralston Analytical have established standards and reputations.
When you’re evaluating kratom quality, the COA is one piece. Combine it with vendor reputation, customer reviews, and price positioning. A suspiciously cheap product with a perfect COA deserves skepticism.
Action Steps: Your Buyer Checklist
Step 1: Request or locate the COA. Before buying, ask the vendor for a COA linked to your specific product batch. If they can’t or won’t provide it, buy elsewhere.
Step 2: Verify the key sections. Check that the COA includes alkaloid profile, heavy metals (all four), microbial testing, and moisture content. Compare alkaloid ranges to the vendor’s stated product type.
Step 3: Compare and follow up. Compare the COA to other vendors. If something looks off, email the vendor and ask for context. How they respond tells you a lot.
Related Resources
To understand how alkaloid content fits into broader kratom quality, see our guides on kratom pills vs extract capsules for format comparisons, and how kratom is harvested and processed to understand the supply chain behind those test results.
A: Mitragynine is the primary alkaloid in kratom leaf. 7-hydroxymitragynine vs traditional kratom explains how this alkaloid compares in concentration and how it relates to different kratom strains. Both are naturally present in kratom, but mitragynine is typically 10–20 times more abundant.
A: Harvest timing, growing conditions, post-harvest processing (drying, fermentation), and storage all affect alkaloid content. Additionally, different labs may use slightly different testing methods, which can cause variation. Reputable vendors test every batch and show consistent results within a reasonable range.
A: ND stands for “non-detectable.” It means the contaminant (heavy metal, bacterial pathogen, etc.) is below the lab’s detection threshold. For microbial testing and heavy metals, ND is what you want to see.
A: Transparency is a baseline indicator of vendor integrity. If a vendor claims their kratom is high-quality but won’t show testing data, that’s a significant red flag. There’s no legitimate reason to hide test results.
A: Ideally every batch, or at minimum every 2–3 batches. Testing frequency shows how seriously a vendor takes quality control. Ask when the COA was generated relative to when you’re placing your order.
Take the Data Seriously
A kratom COA is public information most vendors would rather you ignore. Reading it requires a little patience, but it eliminates guessing. You can verify alkaloid profiles, confirm heavy metals are non-detectable, and hold vendors accountable for what they sell.
Start with Tusk Kratom products; every order includes a current batch COA. Use it as a baseline to understand what quality looks like, then apply the same standards to any vendor you buy from. The vendors worth buying from will have no problem showing their data and answering your questions about it.