1. Per-batch Certificate of Analysis (the most important signal)
A real COA is a one-to-two-page lab report tied to a specific batch number, from a named third-party laboratory with accreditation credentials. It reports mitragynine percentage, 7-hydroxymitragynine content, contamination panels (heavy metals, microbials, often pesticides), and the testing methodology used.
What it proves: the batch is what the label says, the lab can be contacted and the result can be verified, and the vendor is willing to be held accountable to a specific measurement rather than a marketing claim.
How to verify: look for a report before buying and match its identifiers to the product. 4 Leaf Herbals publishes selected product- and batch-specific reports on its lab results page. See our COA literacy guide for how to read one once you have it.
2. Mitragynine and 7-OH disclosure on the label
KCPA-compliant labels (and quality-leading non-KCPA vendors) disclose mitragynine content per serving on the product label itself, not just in the COA. For extracts and gummies, the label should state milligrams of mitragynine per dose; for powder, the label should give percentage by weight.
What it proves: the vendor is transparent about dose, the user can do their own math, and there is no plausible deniability about "stronger than advertised" batches that drive accidental over-doses.
Synthetic 7-OH products — concentrated 7-hydroxymitragynine, sometimes sold as "7-OH tablets" — are a different category from natural-leaf kratom and deserve separate evaluation. See our synthetic 7-OH guide for why.
3. Contamination panel coverage
A real COA covers at minimum:
- Heavy metals: lead, cadmium, arsenic, mercury — all measured in ppm, compared to USP or AHPA recommended limits
- Microbials: Salmonella, E. coli, total aerobic plate count, yeast and mold
- Pesticides: panel covering at least 50+ common agricultural chemicals
Reputable vendors reject batches that fail any of these tests. The 2018 Salmonella outbreak that drove the FDA's enforcement posture against kratom was a contamination event, not a kratom-pharmacology event — making microbial testing especially important for a product imported from tropical regions.
4. AKA GMP audit status
The American Kratom Association's Good Manufacturing Practices program audits vendor facilities, processes, supply chains, and quality systems annually. GMP-qualified vendors have demonstrated they can meet a defined operational standard.
What it proves: a third party has inspected the vendor's operations beyond just lab tests. Recordkeeping, sanitation, supply-chain verification, and personnel training all factor in.
Caveat: AKA GMP is voluntary and not equivalent to FDA GMP for food manufacturing. It is the strongest voluntary signal currently available in the US kratom market, but it is not regulatory law in most states. See our GMP standards guide for the program in detail.
5. KCPA compliance
The Kratom Consumer Protection Act sets state-level legal minimums: 21+ age verification, mandatory mitragynine disclosure, prohibition of synthetic alkaloids, contamination thresholds, and accurate labeling. KCPA has passed in over a dozen states as of 2026, and vendors operating in those states are legally required to comply.
What it proves: even in non-KCPA states, vendors who voluntarily comply with KCPA-equivalent standards demonstrate they are running to consumer- protection norms rather than the regulatory floor. KCPA compliance and AKA GMP overlap heavily — most vendors that meet one meet the other.
6. Vendor transparency on sourcing
Reputable vendors will tell you, when asked or proactively on their site, where their leaf material comes from at the country and ideally region level. "Indonesian Borneo, sourced from a network of growers in West Kalimantan" is a meaningful statement. "Premium kratom sourced from Southeast Asia" is not.
What it proves: the vendor knows their supply chain, has a relationship with growers, and can trace problems back upstream if a batch tests poorly. Vendors who buy through anonymous brokers cannot do any of this — they are essentially flipping bulk product without traceability.
Our supply chain guide and trustworthy vendor guide cover what to look for in sourcing claims.
7. Packaging integrity
Packaging matters more than most users realize. Look for:
- Tamper-evident seals on the primary packaging
- Light-blocking packaging (kratom alkaloids degrade with UV exposure)
- Moisture barriers (humidity drives microbial growth)
- Batch number printed on the package, matching the COA
- Expiration or "best by" date
- Lot number for product recall traceability
What it proves: the vendor has thought through how product behaves between their warehouse and your kitchen. Cheap clear bags with no batch markings are a sign of a vendor cutting corners. See our storage and shelf-life guide for how packaging affects what reaches you.
8. Real customer service
Quality vendors answer their phone, respond to email within 24–48 hours, and have a real person handling questions about COAs, shipping, and returns. Quality vendors also do not aggressively upsell — they sell their products at clearly listed prices without surprise additions at checkout.
What it proves: the vendor is operating a real business with operational capacity, not a flip-shipping setup that disappears after a few months. For a regulated-but-not-regulated product like kratom, the vendor's ability to stand behind their product over time matters significantly.
9. Honest content (the meta-signal)
Look at how the vendor writes about kratom on their own site. Quality vendors describe both benefits and risks — they discuss tolerance, dependence, drug interactions, the difference between leaf and extract, when to skip a dose, when to break, who should not use kratom. Vendors that only discuss benefits, that promise unrealistic effects, that compare kratom favorably to prescription medication, or that ignore side-effect education are signaling they care more about conversion than customer outcome.
What it proves: the vendor has a long-term relationship with their customers in mind. Honest content sells slower per visitor but produces repeat customers who trust the brand. It is the cheapest possible quality signal — you can evaluate it in 10 minutes of reading the vendor's site — and it correlates with the other eight signals above more reliably than any single one.
How to use this checklist
Before buying from a new vendor:
- Find the COA for the specific product you are considering. If you cannot find it in two clicks, that is the answer — move on.
- Verify the COA covers heavy metals, microbials, and pesticides. Confirm the mitragynine content matches the label.
- Check for AKA GMP and KCPA compliance signals.
- Look at sourcing language — country, region, and grower-relationship detail.
- Read at least two articles on the vendor's site. Look for risk-honest content, not just product promotion.
- Test customer service before placing a large order — email a question about COAs and see how they respond.
Five vendors will pass the first three steps but fail steps four through six. Two will pass everything. Those are the vendors worth a long-term relationship.
The 4 Leaf Herbals take
Do not rely on a vendor's self-assessment. 4 Leaf Herbals publishes selected product- and batch-specific reports on its Lab Results page. Match the product and lot or batch identifier and review the report's laboratory, analytes, methods, limits, and results. Read our about page for current company information, or browse the shop for current product labels and availability.