Nothing routinely checks what is inside a packet of kratom before it reaches a buyer in Europe or the United States. No authority sets a limit for lead in it, samples it at the border as a matter of course, or holds anyone to a published specification. That is not an accusation aimed at any particular seller. It is a description of the regulatory position, and it is the reason this page exists.
Every so often somebody has looked anyway. Regulators have run laboratory analyses, academic groups have bought products off shelves and tested them, and forensic toxicologists have worked backwards from deaths. This page collects what those tests found. It is a short list, because there are not many of them.
Why nothing checks
In the European Union, kratom is an unauthorised novel food, meaning a food not eaten to any significant degree in the EU before 15 May 1997 and therefore not permitted on the market until it has been through a safety assessment. Kratom has never been through one. Our EU legal page sets out what follows from that. The part that matters here is narrower: because no authorisation exists, there is no agreed specification for the product, no contaminant limit written for it, and no testing regime attached to it. There is nothing to test against.
The position in the United States is different in mechanism and similar in effect. The FDA has not approved kratom for any use and has taken repeated enforcement action, but products still reach shops and websites without premarket testing.
So when a bag of powder arrives, the honest description is that nobody knows what is in it until somebody analyses that specific bag.
Salmonella, 2017 to 2018
The largest documented failure was a foodborne outbreak. CDC, state health officials and the FDA investigated a multistate outbreak of salmonella infections and concluded that kratom was the likely source.
The final tally was 199 people infected across 41 states, with illness onset dates running from 11 January 2017 to 8 May 2018. Of the 132 people whose records included the information, 50 were admitted to hospital, which is 38 percent. No deaths were reported. Of 103 people interviewed, 76 said they had consumed kratom, most often as powder.
Two details from that investigation say more than the case count. Investigators found 85 different DNA fingerprints of salmonella across the sampled kratom products, which points at contamination arising in many places rather than one bad batch. And when CDC closed the investigation it stated plainly that no single common source had been identified, so contaminated product might still be on sale.
Lead, nickel and other metals
In April 2019 the FDA published laboratory testing of 30 kratom products obtained from a range of sources. The analysis found levels of lead and nickel that exceed safe exposure for oral daily intake, judged against the agency’s own elemental impurities guidance. The FDA’s stated concern was chronic rather than acute: a long-term user, it said, could potentially develop heavy metal poisoning, with nervous system or kidney damage, anaemia, raised blood pressure and increased cancer risk among the possible consequences.
An independent academic group reached a similar result on a smaller sample. Prozialeck and colleagues (2020) bought eight kratom products from shops in the western suburbs of Chicago and tested them. Seven of the eight carried significant levels of nickel, lead and chromium. The eighth was clean.
That last sentence is worth sitting with. One product in the sample was fine. The problem is not that kratom is inevitably contaminated. It is that contamination varies between products and the buyer has no way to tell which one they have.
If you are ever handed a laboratory report for a specific product, reading it is a skill of its own, and what it means turns on how much you take rather than on the number by itself. That is covered separately in how to read a heavy metal test.
Bacteria and fungi
The same Chicago study also cultured the products for microbes. Six of the eight grew bacteria or fungi. None of them grew salmonella specifically, which is a useful corrective: the 2018 outbreak organism was not present, but other organisms were, in most of what they bought.
The amount in the scoop is not a fixed thing
This is the finding with the most direct practical consequence, and it gets the least attention.
Prozialeck and colleagues measured mitragynine, kratom’s most abundant psychoactive alkaloid, in each of their eight products. The concentrations ranged from 3.9 to 62.1 milligrams per gram of powder. That is roughly a sixteen-fold spread across products bought in the same handful of shops in the same suburb.
The consequence is that weight is not dose. Two grams of one product and two grams of another can differ by more than an order of magnitude in how much active alkaloid they contain, and nothing on either package would tell you. Anyone reasoning about kratom in grams, including every dosing figure circulating online, is using a unit that does not measure the thing they think it measures.
Things added that were never on the label
The most serious documented case of adulteration is Swedish, and it killed people.
A preparation sold online as “Krypton” was powdered kratom leaf with O-desmethyltramadol added to it. O-desmethyltramadol is the active metabolite of tramadol, a prescription painkiller, and it is a considerably stronger opioid-receptor agonist than tramadol itself. Kronstrand and colleagues (2011) reported nine fatal intoxications in Sweden in under a year in which both mitragynine and O-desmethyltramadol were found in postmortem blood.
The forensic detail that matters: neither tramadol nor N-desmethyltramadol was present in those samples. If the deceased had taken tramadol, the parent drug and its other metabolites would have shown up. Their absence implies the pure metabolite had been added to the powder deliberately. The authors concluded that this addition contributed to the deaths, and that intake of Krypton “is not as harmless as it often is described on internet websites.”
Nobody buying that product could have detected it. It was sold as kratom, it looked like kratom, and it contained kratom.
Concentrated and synthetic derivatives
The current version of the same problem is 7-hydroxymitragynine, usually written 7-OH. It occurs naturally in kratom leaf in trace amounts and is far more potent at opioid receptors than mitragynine. Products concentrating or synthesising it are now sold in the United States in forms that bear little relation to leaf powder.
In July 2026 the DEA began temporary scheduling proceedings for 7-OH above a proposed threshold, along with three synthetic derivatives that do not occur in the plant at all. The FDA has stated that these actions target concentrated and synthetic products rather than natural leaf containing only trace 7-OH. We covered the notice and the claims made about it in more detail here.
For a buyer the relevant point is that “kratom” on a label now covers a range of preparations with genuinely different pharmacology, and the strongest of them are the newest.
What a lab report settles, and what it does not
A reader who has got this far usually wants to know whether a certificate of analysis solves the problem. It helps less than it looks.
A certificate describes one batch, at one moment, on the tests that were ordered. It is supplied by the party selling the product, and a reader has no way to verify that the tested batch and the packet in their hand are the same material. There is no accredited certification scheme for kratom in the EU, because certification requires an authorised specification to certify against, and there is not one.
So the absence of a test result tells you fairly little, and the presence of one tells you less than it appears to. We are not going to turn that into a checklist. A checklist would imply that a reader can sort the market from a screen, and the evidence above is mostly a demonstration that they cannot.
What none of this can tell you
Prevalence. That is the large gap and it should be stated clearly.
The FDA tested 30 products. Prozialeck and colleagues tested eight, bought in one American metropolitan area. Neither is a random sample of anything, and we found no published systematic testing programme covering the European market at all. Sampling that targets suspected problems will find problems at a higher rate than the market average, which is what targeted sampling is for.
So we cannot tell you what proportion of kratom sold in Europe is contaminated, adulterated or mislabelled. Nobody can, on the published evidence. Anyone quoting you a percentage is estimating, and the honest answer is that the measurement has not been done.
The honest position
What the testing supports is narrow and reasonably firm. Kratom products have been found carrying salmonella, other bacteria and fungi, lead, nickel and chromium; their alkaloid content varies enormously between products; and on at least one documented occasion a preparation sold as kratom contained an added opioid that killed nine people.
What it does not support is a claim about how common any of that is, or a way for a reader to tell a clean product from a contaminated one by looking.
You may have expected this page to end with a list of sellers to trust. It will not. We do not rate, rank or recommend vendors, and our disclosure explains the conflict of interest that makes that rule non-negotiable here.
If you know of a European testing programme or dataset we have missed, we would genuinely like to see it. Write to editorial@wikikratom.com.