Kratom-associated hepatotoxicity: what it is and what to watch for

At a glance: kratom-associated hepatotoxicity

Key Takeaways

• Kratom-associated hepatotoxicity means kratom-caused liver injury. It is a form of drug-induced liver injury documented in the NIH LiverTox database and the DILIN prospective registry.
• The most common pattern is cholestatic, meaning elevated bilirubin and alkaline phosphatase, often presenting with jaundice and itching. Mixed and hepatocellular patterns are also reported.
• It is a diagnosis of exclusion. Clinicians rule out viral hepatitis, autoimmune disease, bile-duct obstruction, and other medications before attributing injury to kratom.
• It is uncommon and usually reversible. Most documented cases improve once kratom is stopped, with supportive care. Acute liver failure has been reported but is rare.
• Symptoms warrant medical attention. Jaundice, dark urine, or persistent right-upper-abdominal pain should prompt stopping use and seeing a clinician for liver-function testing.

What the term means

Drug-induced liver injury is liver damage caused by a substance rather than by a virus, an autoimmune process, or a structural problem like a blocked bile duct. Kratom-associated hepatotoxicity sits within the broader category of DILI from herbal and dietary supplements.

Alternative and herbal supplements have become the second most common cause of DILI in the United States, and kratom has been specifically implicated. The NIH's LiverTox database, which catalogs drugs and substances known to cause liver injury, includes a kratom entry documenting that kratom use "has been associated with rare instances of acute liver injury."

Kratom-associated hepatotoxicity is liver injury attributed to kratom use after other causes have been excluded.

The mechanism is not fully understood. Unlike acetaminophen-induced liver injury, which follows a predictable dose-dependent pattern, kratom-associated liver injury appears to be idiosyncratic, meaning it affects a small number of users in ways that do not clearly correlate with dose or duration. This idiosyncratic pattern is common among herbal-supplement-related DILI cases generally.

What the injury looks like

Pattern on blood tests

The most commonly reported pattern in kratom-associated liver injury is cholestatic, meaning the markers related to bile flow are the most prominently elevated. Specifically:

• Bilirubin: elevated, sometimes markedly so, which is what causes the yellow coloring of the skin and eyes (jaundice)
• Alkaline phosphatase (ALP): elevated
• ALT and AST: may be elevated but often less dramatically so than in hepatocellular injury

A mixed pattern, in which both cholestatic and hepatocellular markers are elevated, has also been reported. Purely hepatocellular presentations (where ALT and AST dominate) are less typical but documented.

Biopsy findings from published cases describe cholestasis (bile buildup in liver tissue) and bile-duct injury. A 2023 Journal of Hepatology case documented these histologic findings in a patient who presented with jaundice after kratom use.

Symptoms

The DILIN case series described the typical patient as a previously healthy person, most often male, presenting with jaundice and itching as the primary complaints.

Timing

The DILIN data found a median latency of approximately 22 days between kratom use and onset of symptoms. Published case reports describe a range of roughly 1 to 8 weeks. This timing pattern, emerging after a period of regular use rather than immediately, is consistent with idiosyncratic DILI and with what has been observed with other herbal supplements.

How doctors diagnose it

A diagnosis of exclusion

There is no single test that confirms kratom-associated hepatotoxicity. Diagnosis requires excluding other causes of liver injury that are more common and more definitively testable. Clinicians will typically evaluate:

• Viral hepatitis (hepatitis A, B, C, and E serology)
• Autoimmune liver disease (ANA, anti-smooth muscle antibody, immunoglobulin levels)
• Bile-duct obstruction (ultrasound or other imaging)
• Alcohol use history
• Acetaminophen levels
• Other prescription medications or supplements the person is taking

Only after these causes are excluded or deemed insufficient to explain the degree of injury is kratom-associated hepatotoxicity a supportable diagnosis.

Causality scoring with RUCAM

Clinicians use a structured scoring system called RUCAM (Roussel Uclaf Causality Assessment Method) to systematically assess how likely it is that a given substance caused the liver injury. RUCAM scores the time to onset, the pattern of injury, known risk factors, concomitant drug use, prior published reports of the substance causing liver injury, recovery course, and whether symptoms recur if the substance is restarted.

DILIN investigators have used RUCAM scoring to establish causality in kratom cases, with most kratom-associated cases rated as "probable" or "highly likely" under this framework.

The confounder problem

Kratom cases are particularly difficult to evaluate cleanly because of several overlapping factors:

This is why the DILIN and published case reports consistently note that isolating kratom as the definitive cause requires careful exclusion of these confounders, and why the mechanism remains unclear.

Prognosis and what to do

What happens when you stop

Most documented cases of kratom-associated liver injury show improvement after kratom is stopped and supportive care is provided. Supportive care may include IV fluids, nutritional support, and management of symptoms such as itching. Many patients in published cases required hospitalization during the acute phase.

Acute liver failure from kratom has been documented in the literature, but it is rare. The 2023 Journal of Hepatology review noted kratom has been "implicated in acute liver injury (mostly cholestatic), acute liver failure, organ dysfunction, toxicity, coma, seizures, and death," while describing these severe outcomes as uncommon relative to the overall case population.

What to do if you have symptoms

If you notice jaundice, dark urine, persistent nausea, or right-upper-abdominal pain and have been using kratom:

• Stop kratom use
• See a clinician promptly; do not wait for symptoms to resolve on their own
• Tell your provider specifically that you have been using kratom, including the type of product and how long
• Ask for liver function testing: ALT, AST, alkaline phosphatase, and total bilirubin

Early identification and discontinuation is associated with better outcomes. The liver has significant regenerative capacity, and most cases documented in the literature resolved over weeks with supportive care.

The broader picture

Kratom-associated hepatotoxicity is one more way the "natural supplement" framing misrepresents the pharmacological reality of kratom products. Liver injury from herbal products is well-documented across many botanical substances; natural origin is not a safety guarantee. For concentrated 7-OH products specifically, the risk profile may differ from botanical leaf in ways that are still being characterized. The companion article 7-OH and Liver Toxicity covers that evidence.

If kratom or 7-OH use has become difficult to stop, buprenorphine-based treatment is available through telehealth in most states. Learn how Bicycle Health's treatment works.

Frequently Asked Questions

What does "kratom-associated hepatotoxicity" mean?

It means drug-induced liver injury attributed to kratom. "Hepatotoxicity" is liver damage, and "kratom-associated" means kratom is the identified cause. The diagnosis requires ruling out other more common causes of liver injury, including viral hepatitis, autoimmune disease, bile-duct problems, and other medications.

Is kratom liver damage common?

No. Kratom-associated liver injury is documented but relatively uncommon relative to the large number of people who use kratom. The DILIN registry enrolled 11 cases over a 15-year period. The case count increased in the final years of that period as kratom use grew. Not every kratom user will develop liver injury; it appears to occur in a small subset, possibly reflecting individual susceptibility factors that are not yet well understood.

What does kratom liver injury feel like?

The most common symptoms are yellowing of the skin or whites of the eyes (jaundice), dark or tea-colored urine, pale stools, itching, fatigue, and sometimes pain or discomfort in the upper-right abdomen. Nausea and loss of appetite are also common. These symptoms can take one to several weeks of use to appear.

Can you recover from kratom liver injury?

Most documented cases have recovered after stopping kratom with supportive care. The liver has significant regenerative capacity. Recovery can take weeks to months depending on severity. Acute liver failure from kratom is documented but rare. Earlier identification and discontinuation is associated with better outcomes.

How do doctors know kratom caused the liver injury?

They use a structured diagnostic process: first ruling out more common causes (viral hepatitis, autoimmune disease, alcohol, other medications), then applying a causality scoring tool called RUCAM that weighs timing, pattern, recovery course, and prior published cases of the substance causing injury. It is a diagnosis of exclusion, which means other explanations must be eliminated before kratom is named as the cause.