Who Should Not Take Kratom?

Most writing about kratom is aimed at people who are going to take it. This lesson is about the people who shouldn’t. Read it as an exclusion list and nothing more.

The last lesson showed that the risk sits in the person rather than in the plant. This one covers the circumstances known to make that risk worse, and how thin the evidence behind each one really is.

There Is No Official List

The two federal agencies that have looked hardest at kratom don’t publish a caution list. The FDA warns consumers not to take kratom at all, and it names three risks: liver toxicity, seizures and substance use disorder. The DEA states that kratom has no legitimate medical use in the United States. Neither one writes an exclusion list¹, and the reason matters. An exclusion list implies that everyone not named on it is fine, and that isn’t their position.

What follows comes from case reports and clinical references written for doctors. One of them says plainly that there’s little information about absolute contraindications for kratom. So this is the best that’s been published, and it isn’t complete.

The Evidence Is Not Equally Strong

Liver injury has the strongest case behind it, and it needs its numbers told in both directions.

Start with what this evidence isn’t: nobody gave anyone kratom. Since 2003, a federally funded network of hospitals has enrolled patients with unexplained liver injury. It works out what caused each one. Three liver specialists review every case and rule out other causes. Then they agree on how likely the suspected product is, on a five-point scale. Between 2003 and 2019, the network enrolled 404 liver injury cases tied to herbal and dietary products. Eleven of them scored definite, highly likely or probable for kratom. That is about 3 percent of the herbal and dietary cases, and 1 percent of all the liver injury cases in the registry.

Here is what happened to those eleven. Nine were men, and the median age was 40. All of them turned yellow, and eight were admitted to the hospital. Three developed features of liver failure. None died, none needed a transplant, and all of them got better. Researchers got hold of three of the products. A federal laboratory found kratom’s main alkaloids in them and no other adulterant. So those patients were taking real kratom rather than something contaminated. That doesn’t tell you what caused the injury.

Eleven is a floor, not a total. It counts only patients who reached a participating hospital and cleared that review. Three of the eleven came in the network’s first decade and eight in its final three years. The NIH liver injury reference counts more cases than the network does, and it grades kratom a likely cause of liver injury.

Among those patients, the median time from starting kratom to first symptoms was fourteen days, with a range of five to twenty-eight. That isn’t a countdown. It is simply where the reported cases clustered. If something changes after you start a new product, that is a question for a doctor.

Seizures rest on much less. A 2025 systematic review of the literature and two federal adverse event databases found twenty patients in total. Only one of the twenty had a measured level of kratom’s main alkaloid in his body. Half were taking other substances, and several already had epilepsy or had undergone brain surgery. Nobody has worked out a mechanism.

Substance use disorder sits in between, and the FDA says so itself. Its own page states that no well-designed study of how habit-forming kratom is has been run. So the gap isn’t overstated warnings. It is that the work needed to say who is at risk hasn’t been done.

Pregnancy and Nursing

This is the one exclusion that appears in every published source. A 2023 review gathered every published case it could find of kratom taken during pregnancy. That came to ten reports covering twelve mother and infant pairs. Nine of the twelve women had taken kratom daily, most of them for months before becoming pregnant. Most were identified only after giving birth, when the baby began showing signs of withdrawal. Ten of the newborns showed neonatal abstinence syndrome, starting on day two on average and peaking by day four. Seven were given morphine and went home between day twelve and day fourteen.

Twelve mother and infant pairs is a set of case reports, not a study of risk, so it can’t tell you your odds in either direction. Pregnant, think you might be, or nursing? That’s a conversation with a doctor. It isn’t a call to make from a website.

Existing Liver, Kidney, Heart, Lung or Nerve Conditions

Clinical references tell people with these conditions to avoid kratom, and case reports describe harm to each of those organ systems. That advice is caution rather than measurement. But an organ already under strain is a poor candidate for an added load nobody has studied.

Anyone Taking Prescription Medication

Kratom’s alkaloids get in the way of enzyme systems² the body uses to clear other drugs. Mitragynine appears to block a clearance route called glucuronidation, and buprenorphine and ketamine are two of the drugs that depend on it. When a clearance route is blocked, another drug can build up rather than simply adding to what kratom does. The clinical reference is plain about it: anyone taking a drug cleared by that pathway should avoid kratom or ask a clinician first.

Kratom doesn’t show up on a standard drug panel either. A surgical team or an emergency crew won’t know unless somebody tells them, so if you have surgery booked, say so beforehand.

A History of Substance Use Disorder

This is the exclusion people are most likely to argue with. Taking several substances is a known risk factor in kratom-associated deaths. Kratom builds tolerance, can lead to dependence³, and brings a withdrawal syndrome⁴ when it stops. Someone with that history would be handling a product that carries the same problem.

We won’t soften this. Kratom is not an answer to anyone’s dependence on anything, and we never describe it that way. If dependence is the reason kratom is on the table, that’s a conversation for a doctor or an addiction specialist.

Anyone Under 21

Whole Earth Gifts sells to adults 21 and over. Some states set a lower limit and some set none. Our limit doesn’t come from a study, because no study exists. The published work covers adults, and where nothing has been measured in young people, a lower limit isn’t the answer.

If You Are Not On This List

Then you’ve reached the end of an incomplete list, which is a different thing from being cleared. Everything above was built from case reports, adverse event databases and clinical references, and none of those can tell one person their own risk. Only one item here has a forward-looking study behind it, and on that one, researchers say plainly that they can’t tell who is susceptible.

So the useful move isn’t to check yourself against a list. It’s to write down what you take and what happens. That gives a doctor something real to work with, and it means you catch a change while it’s small.

Key Takeaways

• Liver injury is rare, serious, and reversible in the cases documented so far. Eleven scored definite, highly likely or probable in twenty years of a national hospital registry. All turned yellow and three reached liver failure. All of them got better. Nobody has shown how it happens or who is susceptible.
• Pregnancy and nursing is the one exclusion in every published source. Ten of twelve documented newborn exposures showed a withdrawal syndrome.
• With prescription medication, the risk isn’t that kratom adds to the drug. Kratom can block the route your body uses to clear it, so the drug builds up.
• Kratom doesn’t appear on a standard drug panel. A surgical or emergency team won’t know unless you tell them.
• Kratom is not an answer to anyone’s dependence on anything. A history of substance use disorder is a reason to stay away, not a reason to try it.