Dietary supplements cause a growing share of liver injuries in the United States, rising from 7% of all drug-induced liver injury cases in 2005 to 20% by 2014. The most common culprits are green tea extract, anabolic steroids and related compounds, and multi-ingredient products marketed for weight loss or bodybuilding. Some of these injuries are severe enough to require a liver transplant or result in death.
Green Tea Extract
Green tea extract is the single most commonly implicated herbal agent in liver injury cases tracked by the U.S. Drug Induced Liver Injury Network. The compound responsible is EGCG, a concentrated catechin found at much higher levels in extract capsules than in brewed tea. The European Food Safety Authority concluded that daily doses at or above 800 mg of EGCG taken for four months or longer caused significant elevations in liver enzymes in a small percentage of users, typically under 10%. Below 800 mg per day, studies lasting up to 12 months showed no evidence of liver toxicity.
That said, individual sensitivity varies widely. Case reports have documented liver damage at doses as low as 146 to 292 mg of EGCG per day when taken for several weeks to months. One product that was pulled from the market caused toxic hepatitis at a recommended daily dose of just 375 mg of EGCG, with onset ranging from 9 days to 5 months. Symptoms include yellowing of the skin or eyes, dark urine, abdominal pain, nausea, and unusual fatigue. The pattern is almost always direct damage to liver cells rather than bile duct blockage.
Drinking a few cups of green tea is not the same risk. The concern is concentrated extract in supplement form, where EGCG levels can be many times higher than what you’d get from a cup of tea.
Bodybuilding Supplements
Anabolic steroids, particularly a class known as 17-alpha-alkylated steroids, have a long history of causing a distinctive liver injury marked by intense, prolonged jaundice. These compounds are sometimes sold openly, but more often they’re hidden inside products labeled as “prohormones” or “natural testosterone boosters.”
A newer category of concern is selective androgen receptor modulators, commonly called SARMs. Sold online under names like Ligandrol (LGD-4033), Ostarine, RAD-140, and Andarine, these are marketed as safer alternatives to steroids. They are not. Multiple cases of severe cholestatic jaundice, where the liver can’t properly drain bile, have been linked to SARMs. The injury pattern closely resembles traditional anabolic steroid damage. Other agents found in bodybuilding supplements and linked to liver cases include Cardarine (GW-501516) and Ibutamoren (MK-677).
None of these compounds are approved as dietary supplements. They are unapproved drugs sold through regulatory loopholes, and the doses in commercial products are unpredictable.
Weight Loss Products
Weight loss supplements are a major category of liver risk. Several specific products and ingredients have been flagged over the years. The FDA issued a warning against Hydroxycut in 2009 after reports of liver injury and one death. OxyELITE Pro was linked to a cluster of liver failure cases in Hawaii in 2013, likely caused by the addition of an unapproved ingredient called aegeline. Herbalife products and SLIMQUICK have also appeared repeatedly in liver injury databases.
Garcinia cambogia, a tropical fruit extract popular in weight loss pills, has been associated with cases of acute hepatitis. The challenge with many of these products is that they contain dozens of ingredients, making it difficult to isolate exactly which one caused the damage. In some cases, it may be the combination of multiple compounds stressing the liver simultaneously.
Usnic acid, a compound derived from lichen and once included in the weight loss product LipoKinetix, is another ingredient linked to acute liver failure.
Vitamin A
Preformed vitamin A (retinol) is directly toxic to the liver at high doses. Normal supplemental doses are safe, but intake above roughly 40,000 IU per day (about 12,000 micrograms) can cause damage. That’s approximately 10 times the recommended daily allowance.
Unlike many supplement injuries that appear suddenly, vitamin A toxicity is often chronic. It develops over months to years of moderately excessive intake and causes a specific pattern of damage: excess vitamin A accumulates in specialized storage cells in the liver, causing those cells to become overactive. They produce too much collagen, leading to fibrosis and scarring. Early symptoms include dry skin, cracked lips, joint and muscle pain, fatigue, and mental dullness. By the time liver test abnormalities show up, significant damage may already be underway. This is one reason high-dose vitamin A supplements and excessive liver consumption (an extremely rich dietary source) deserve caution.
Other Herbal Supplements With Liver Risk
Beyond the major categories above, a range of individual herbs and botanicals have been linked to liver injury in clinical databases:
- Kava: Used for anxiety and relaxation, kava has been associated with severe liver damage and was restricted or banned in several European countries.
- Black cohosh: Commonly taken for menopause symptoms, it has appeared in multiple liver injury case reports. Complicating matters, some products labeled as black cohosh have been found to contain other plant species entirely.
- Kratom: Used for pain relief and opioid withdrawal, kratom has been implicated in cases of acute liver injury.
- Niacin (vitamin B3): At high supplemental doses, particularly sustained-release formulations, niacin can cause significant liver enzyme elevations and even liver failure.
- Valerian: A common sleep aid that has appeared in liver injury databases.
- Greater celandine: An herbal remedy used for digestive complaints in Europe, linked to multiple hepatotoxicity cases.
- Pennyroyal: An herbal oil historically used as a folk remedy, highly toxic to the liver even in small amounts.
- Chaparral: A desert plant marketed for various health claims, associated with severe liver damage.
- Germander: Used traditionally for weight loss and digestive issues, well-documented as a cause of hepatitis.
Traditional Chinese medicine formulations and Ayurvedic preparations also appear regularly in liver injury reports. Fo-Ti (also known as He Shou Wu) and herbs containing pyrrolizidine alkaloids, such as comfrey, are particularly notable examples.
Contamination and Hidden Ingredients
Sometimes the listed herb isn’t the problem. In one study, heavy metals or unlisted pharmaceutical drugs were detected in 32% of traditional Chinese medicines collected in California. Among the most common contaminants were methyltestosterone (an anabolic steroid), ephedrine, arsenic, and mercury. Because supplements in the United States face far less regulatory scrutiny than prescription drugs, contamination and adulteration are not rare events.
Products labeled as one herb may contain a completely different plant. Germander has been found in products labeled as skullcap. Various Asian species have been found in products labeled as black cohosh. This means you can do everything right in choosing what you think is a safe supplement and still be exposed to a hepatotoxic substance you didn’t know was in the bottle.
How Liver Injury From Supplements Shows Up
The symptoms of supplement-related liver injury range from none at all to life-threatening. In a large meta-analysis of cases, the most common sign was jaundice, appearing in 46% of patients. Abdominal pain occurred in about 22% of cases, nausea in 17%, and fatigue and loss of appetite were also frequent. More severe cases involved dark urine, pale or clay-colored stools, itching, and fever. On average, liver enzymes were elevated roughly 22 to 28 times their normal upper limit, indicating substantial liver cell damage.
In a 2015 population study, over 18% of acute liver failure cases were attributed to herbal and dietary supplements, and half of those resulted in death or liver transplant. The range of outcomes is wide: some people recover fully once the supplement is stopped, while others progress to organ failure within weeks. Multi-ingredient products are especially difficult to manage because identifying the responsible component takes time, and these products often lack accurate labeling of what’s actually inside.