What supplement is linked to the liver? Safe vs. Risky Options

October 23, 2025 •

4 min read

According to the National Institutes of Health, supplement-induced liver injury has grown to account for up to 20% of all hepatotoxicity cases in the U.S., making the question of what supplement is linked to the liver more critical than ever. While some supplements may support liver function, others pose serious, often unpredictable, risks depending on dosage and individual susceptibility.

Quick Summary

Certain supplements, including kava, high-dose green tea extract, and some multi-ingredient blends, are tied to liver damage. Protective supplements like milk thistle and antioxidants may support function. Individual risks vary and consulting a doctor is essential.

Key Points

Kava and Liver Injury: The supplement kava, used for anxiety, has been clearly linked to severe liver damage and even liver failure in some cases.
Green Tea Extract vs. Tea: Concentrated green tea extract, unlike the beverage, carries a risk of idiosyncratic liver injury, especially at high doses or in genetically susceptible people.
Dose-Dependent Turmeric Risks: While generally safe in food, highly concentrated turmeric/curcumin supplements have been implicated in causing liver damage in certain individuals.
Multi-Ingredient Dangers: Multi-ingredient supplements for weight loss or bodybuilding, like Herbalife and Hydroxycut, have been frequently cited as agents of liver injury.
Supportive Supplements: Some supplements, such as milk thistle, Vitamin E, and Vitamin C, possess antioxidant and anti-inflammatory properties that may support liver function.
Idiosyncratic Reactions: Liver injury from supplements is often unpredictable and varies from person to person, sometimes linked to individual genetic factors and pre-existing health conditions.
When to See a Doctor: Signs like fatigue, nausea, abdominal pain, or jaundice require immediate medical attention and discontinuation of supplements.

Supplements Linked to Liver Injury

The rising number of cases of drug-induced liver injury (DILI) linked to herbal and dietary supplements is a serious public health concern. Many people assume natural products are inherently safe, but this is a dangerous misconception. The liver's job is to filter everything we ingest, making it vulnerable to harm, especially from concentrated or contaminated products. Several popular supplements have repeatedly been flagged for their potential hepatotoxicity.

Herbal Culprits with Documented Risks

Kava (Kava Kava): A supplement used for anxiety, kava has been linked to severe liver damage, including cases requiring liver transplantation. While the frequency is not precisely known, the U.S. FDA has issued warnings, and some data suggests causality in severe hepatitis cases.
Green Tea Extract (GTE): Unlike drinking green tea, highly concentrated green tea extract has been associated with idiosyncratic hepatotoxicity in susceptible individuals. High doses of the antioxidant EGCG are thought to be the primary cause, with a person's genetics potentially playing a role in their risk.
Turmeric/Curcumin: While widely praised for its anti-inflammatory properties, high doses of concentrated turmeric or curcumin have been linked to liver injury in sensitive individuals. The danger lies in concentrated forms and the individual's genetic predisposition to react poorly.
Other Botanicals: Other herbal supplements frequently mentioned in connection with liver injury include ashwagandha, black cohosh, red yeast rice, and Garcinia cambogia, particularly at high concentrations.

Fitness and Multi-Ingredient Formulas

Multi-ingredient supplements (MINS), often marketed for weight loss or athletic performance, pose a significant risk because it is often unclear which specific ingredient is causing the harm.

Pre-Workout Supplements: Some pre-workout formulas contain stimulants and other compounds that have been reported to exacerbate DILI. Ingredients like DMAA and niacin in high doses have specifically been linked to liver issues.
Protein Powders: While generally safe in moderation, excessive protein intake can put a strain on the liver, especially in those with pre-existing conditions. Low-quality products may also contain harmful contaminants that add to the liver's burden.

Supplements that May Support Liver Health

In contrast to the risks posed by some supplements, others have a long history of use and some scientific backing for their potential role in supporting liver function. This is a complex area of research, and results often vary.

Milk Thistle (Silymarin): The active compound, silymarin, is a powerful antioxidant that may help lower liver inflammation. It has been traditionally used to protect the liver and is one of the most studied herbs for this purpose.
Antioxidant Vitamins (C and E): These vitamins help protect liver cells from oxidative stress and free radical damage, which are major factors in liver disease. Vitamin E has shown promise in reducing fat and inflammation in the liver in some studies.
B Vitamins: Certain B vitamins, particularly B12 and folic acid, can be beneficial for liver health, especially in individuals with fatty liver disease.
SAM-e (S-adenosyl-L-methionine): A naturally occurring compound, SAM-e plays a role in liver processes and has been studied for its potential benefits, though evidence is not conclusive.
Glutathione: An antioxidant naturally produced by the liver, glutathione is available as a supplement and may support the body's detoxification processes.

Potential vs. Proven Risk: A Comparison Table


Feature	Potentially Harmful Supplements	Potentially Supportive Supplements
Mechanism of Action	Often idiosyncratic; can involve direct toxicity, overwhelming the liver's processing capacity, or causing oxidative damage in susceptible individuals.	Primarily antioxidant and anti-inflammatory; may aid detoxification pathways and protect liver cells from damage.
Associated Ingredients	High-dose Kava, concentrated Green Tea Extract, concentrated Turmeric, Ashwagandha, Black Cohosh, various ingredients in MINS.	Milk Thistle (Silymarin), Vitamin E, Vitamin C, B Vitamins.
Risk Profile	Unpredictable, can range from elevated enzymes to severe hepatitis and liver failure, especially with high doses or in susceptible individuals.	Generally considered safer, but efficacy and safety can vary. Not a substitute for medical treatment for liver disease.
Key Precaution	Avoid high doses, be aware of genetic risk factors, and be cautious with multi-ingredient blends. Always consult a healthcare professional.	Discuss with a doctor to ensure suitability, especially if you have pre-existing liver conditions.

Watch for These Signs of Liver Damage

If you take supplements and notice any of the following symptoms, it is crucial to stop the supplement immediately and consult a doctor:

Fatigue or feeling unwell
Pain or discomfort in the upper right abdomen
Swollen belly
Nausea or vomiting
Itchy skin
Jaundice (yellowing of the skin and eyes)
Dark-colored urine
Abnormal liver enzyme levels found in routine blood tests

Conclusion

As the use of herbal and dietary supplements continues to grow, so does the risk of associated liver injury. While some supplements, like milk thistle and antioxidants, may offer potential benefits for liver health, many others, particularly concentrated herbal extracts and multi-ingredient formulas, carry documented risks. The liver's reaction is often idiosyncratic, meaning an individual's genetic makeup and other factors play a significant role. The most responsible approach is to exercise extreme caution, particularly with high doses or unproven products. It is always safest to consult a healthcare professional before starting any new supplement, especially if you have an existing liver condition.

For more in-depth information on specific supplement risks, authoritative sources like the National Library of Medicine's LiverTox database are invaluable. LiverTox - NCBI

Frequently Asked Questions

Herbs most frequently linked to liver injury include kava, high-dose concentrated green tea extract, turmeric/curcumin, ashwagandha, and black cohosh.

Excessive consumption of protein powder can strain the liver, especially in individuals with pre-existing liver disease. High-quality products are usually safe in moderation, but overloading the liver with protein is a concern.

Some pre-workout supplements contain stimulants and other compounds that can potentially cause or worsen drug-induced liver injury (DILI). Ingredients like DMAA and high-dose niacin have specific links to liver issues.

Milk thistle extract, or silymarin, has traditionally been used to support liver health due to its antioxidant properties and potential to reduce inflammation. However, it is not a cure for liver disease.

Vitamins with antioxidant properties, such as Vitamin C and Vitamin E, are important for protecting liver cells. Some B vitamins, including B12, may also benefit liver health.

Early symptoms can include fatigue, nausea, upper right abdominal pain, or an elevation of liver enzymes detected in blood tests. More advanced damage can lead to jaundice (yellowing skin/eyes) and itchy skin.

To protect your liver, avoid excessive doses, be cautious with multi-ingredient products, choose high-quality supplements, and always consult a healthcare professional, especially if you have pre-existing liver conditions.