Do Herbs Such as Ashwagandha and Turmeric Cause Liver Damage? A Deep Dive.

 Table of Contents

• Study Overview & Media Reactions
• Estimated Exposure Explained
• Understanding "Potentially Hepatotoxic"
• What the Numbers Actually Say
• Causality and Quality of Reports
• How Supplements Compare to Drugs and Food
• Is the Supplement Industry Really Unregulated?
• Safe Supplement Use Tips
• Conclusion

Study Overview & Media Reactions

A paper published last year in the JAMA Network Open warned that six popular botanical dietary supplements have been associated with liver injury and that millions of Americans are in danger. This study received significant media attention and led to frightening headlines such as “Millions of Americans May Risk Liver Damage from Unregulated Herbal Supplements”.  Top selling botanicals such as ashwagandha and turmeric have been implicated as well as black cohosh, garcinia, green tea, and red yeast rice. 

The study, “Estimated Exposure to Six Potentially Hepatotoxic Botanicals in US Adults”, was conducted by the University of Michigan and claims that 15.6 million Americans may be taking herbal supplements that are damaging to their liver. The authors of the study also state in the media that “the rates of liver injury due to botanical products has been on the rise from 7% in 2004-2005 to 20% in 2013-2014”.  These reports and their alarming headlines have sparked concern among the public regarding the safety of botanical ingredients. 

Natural products industry trade associations, such as the American Botanical Council (ABC) and the Council for Responsible Nutrition (CRN) were quick to respond calling the study and resulting media coverage “exaggerated”, “misleading”, “alarmist”, and “full of inaccuracies and limitations”. ABC chief science officer, Stefen Gafner, PhD commented that “these data are provided without proper context and suggest that the risk of liver injury is much greater than it actually is”.  Steve Mister, president of CRN, goes further by saying that this analysis of herbal supplement use, “when compared to their actual reported risks, only strengthens the case for their safety.”

At Bold Botanica, we have done our own deep dive into this study and its claims and agree that these findings are flawed and greatly exaggerated.  We have found that the key to understanding the claims lies in the words “estimated” and “potentially”. In addition, neither the authors of the study, nor the media, have applied simple math to their own data to give context to their claims.   

Estimated Exposure Explained

The study used data from a survey, the National Health and Nutrition Examination Survey (NHANES), which was conducted between 2017 and 2020 and included questions regarding use of herbal and dietary supplements (HDS). The Dietary Supplement Health Education Act of 1994 defines an HDS as a product that contains a dietary ingredient such as vitamins, minerals, herbs, botanicals, amino acids, and dietary substances that are intended to supplement the diet. The NHANES data showed that 57.6% of those surveyed use HDS products and 4.7% use the specific six botanicals “of interest”. From this they took data from the 2020 US census and extrapolated the potential numbers of US adults taking these six herbal and dietary supplement products. This is how they calculated the number that 15.6 million adults are taking supplements that might be damaging to their liver. So, although it sounds like a study was conducted, the numbers are an estimate using population data.  We note that using data for the entire US population over the age of 18, may not give the most accurate estimate given that the mean age of HDS users is reported to be 52. 

Understanding "Potentially Hepatotoxic"

How did the study determine that the six botanicals “of interest” are hepatotoxic? The study and all the media articles are written as if all six botanicals cause liver damage, and the high risk is a certainty. However, if you read the study you find that they conducted no clinical trial, no animal trial, or even a systematic review of all of the literature. In addition, in the study’s section on “Limitations”, they noted that, “Our study has several important limitations”:

• “There was no opportunity to determine associations with clinical outcomes, such as episodes of idiosyncratic hepatotoxic effects.” This means they were unable to determine if there were other causes of toxicity such as other health issues, drug exposures, genetic factors, or the individual’s unusual response. 
• “Thus, our study was not designed to identify any causal relationship between consumption of the 6 botanicals of interest and the development of liver injury over time.” 

The authors of this study admit that they did not “identify any causal relationship”, yet all the headlines imply that these six botanicals are certainly hepatotoxic. This alone should discredit the entire article. 

Apparently, the authors base their claims on past research and reports on these six botanicals from other sources, which they include in their references. Some of the references are reports from the Drug Induced Liver Injury Network (DILIN), and they also reference the Liver Tox: Clinical and Research Information on Drug Induced Liver Injury 2012 through 2024 Database from the National Institute of Diabetes and Digestive and Kidney Diseases.  Let’s take a look at these references.

How Many Actual Cases? The Numbers Tell a Different Story.

The primary reference cited in the JAMA study was published in Hepatology in 2017, let’s call it the Navarro study. The primary data presented here are from the DILIN, collected over eight years.  They found 130 HDS-related liver injury cases, however at least 45 of them were attributed to bodybuilding products that were adulterated with prescription-strength anabolic steroids. Since these are due to bad actors and not to actual botanical products, they can be removed, leaving 85 cases attributed to HDS. Spread over eight years, this equals 10.6 cases per year.  To put this into perspective, the JAMA study itself estimates that 15.6 million Americans are using HDS per year, do the math for 10.6 cases per year and you get a 0.000068% annual rate of potential injury. Yet due to 10.6 suspected cases per year, the authors declare that HDSs are “Commonly Associated with Liver Injury”.

The same study reports that data from the Drug Induced Liver Injury Network shows that the proportion of rates of liver injury due to botanical products grew to 20%.  JAMA study authors and the news media are reporting that “Data from Drug Induced Liver Injury Network reported the rates of liver injury due to botanical products has been on the rise from 7% in 2004-2005 to 20% in 2013-2014.” However, they conveniently leave out the key word "proportion". This number of 20% represents the proportion of HDS reports of liver injury compared to the number of reports for prescription drug induced liver injury (80%) in a study of 839 cases, so this is not an actual percent of the population. Also, this data is based on volunteer reporting.  There is no way to know if drug induced reporting is underreported or HDS reporting is overreported, so this ratio is totally relative. 

Just below that it states:

 

“Perhaps the best estimate for the incidence of HDS (herb and dietary supplement) related liver injury comes from a population-based survey in Iceland where the overall incidence of DILI in 2011–2012 was estimated to be 19 cases per 100,000 persons. In that study, 16% of cases were attributed to HDS, suggesting that the incidence of HDS-related acute liver injury was 3 per 100,000 persons.”

So the Navarro article, the JAMA article and the media carelessly make it sound like 20% of us are experiencing liver damage from herbs, when based on the numbers shared above, the reality is that between 0.000068% to 0.003% of us might experience liver damage from herbs and supplements.

When examining cases per each botanical it becomes very difficult to determine the actual number of cases.  Many articles, reviews, and databases may be tracking the same cases and thus include duplicates.  Also, most sources include cases reported globally, and it is even more challenging to separate out cases only occurring in the US. We did some digging, and this is what we found:

Ashwagandha and Turmeric

Turmeric and ashwagandha are among the top-selling herbal products with reported 2023 US retail sales of $170 and $140 million, respectively, and these numbers exclude online sales so they could be doubled.  We dug into the cases referenced in the JAMA article and found that for ashwagandha there have been 6 potential liver injury cases reported in the US between 2017-2022, so 1 per year on average.  The JAMA article estimates that there are 1.25 million users of ashwagandha in the US.  Let’s do the math! So, the annual occurrence of liver injury from ashwagandha may be 0.000080%. 

Ashwagandha has been used safely for thousands of years.  Even the LiverTox database which is referenced in the JAMA article, states that “Ashwagandha is considered generally safe and without major side effects”, and that in clinical trials there have been no reports of adverse events.  The database lists nine references that found that ashwagandha is beneficial and without adverse effects; one study found that ashwagandha helped to decrease hepatic injury.  They cite 8 cases of potential liver injury in the US from 2017 to 2024, so again, 1 per year on average. 

The numbers are similar for turmeric, another herb that has been used safely for centuries including massive culinary usage throughout Southeast Asia.  The JAMA article references up to 18 potential liver injury cases in the US between 2009-2022.  For these we are not able to tell if they may include duplicates.  So, 18 cases over 14 years (average 1.3 cases per year), and the 11.4 million users cited in the JAMA report= 0.000011% chance of liver injury.  In exploring the LiverTox data, they list up to 21 potential US cases (may include duplicates) over 12 years, so an average of 1.8 cases per year.  They state that “Both turmeric and curcumin were considered to be generally safe for many years”, but that recently there have been isolated cases of liver injury.  Due to these isolated cases, they determine that turmeric products are a “likely cause of clinically apparent liver injury”.

Regarding some of the other six potentially damaging herbs, there are some higher numbers of reported cases.  On these we were not able to determine how many have occurred in the US versus globally.  Here is what we could pull from the different references. 

 

 

Causality and Quality of Reports

Determining drug or HDS causality in induced liver injury is extremely complex and difficult. It is far from an exact science and is a “diagnosis of exclusion that rests upon ruling out other common causes of liver disease”.  Common methods such as the RUCAM scale should consider risk factors such as age and alcohol use, the use of other medications with potential for liver damage (comedications or concomitant drugs), and the existence of concurrent diseases and health conditions (comorbidities).

Case studies should consider the following when evaluating causation:

1. Risk factors – Age, weight, alcohol use, genetics – age over 55, obesity, and even regular alcohol consumption of 1 to 3 glasses per day, can cause increased risk of liver injury, especially for women. There are also well-known genetic differences that may contribute to an increased risk for liver injury, for example, the presence of HLA-B*35:01 allele has been found to be associated with higher liver injury risk in those taking drugs and herbal supplements such as turmeric, green tea, and garcinia.

2. Comorbidities – Health conditions such as hepatitis, alcoholic liver disease, heart failure, diabetes, non-alcoholic fatty liver disease, viral infections including herpes, cancer, autoimmune hepatitis, hypertension, pregnancy, idiosyncratic hepatitis, and others can predispose someone to liver damage or increased risk.

3. Concomitant drugs – Over 1,000 drugs can cause liver damage. Certain common drugs are known to be hepatotoxic, such as antibiotics, acetaminophen, non-steroidal anti-inflammatories, statins, birth control pills & progestins, antifungals, antivirals, and many others. Many Americans are taking multiple drugs, and little is known about the liver injury risks of multi-drug interactions. Concomitant substances may also include other dietary supplements. 

4. For Dietary Supplements – In order to exclude other causes, researchers should note more detailed information such as the brand name, ingredients, suggested dose, dose taken, type of extract and solvents used, and test for any contaminants or adulteration of the product.  Some weight loss and bodybuilding supplements have been found to be adulterated with synthetic drugs such as stimulants or anabolic steroids, and others such as Black Cohosh may contain the wrong plant species. Adulteration is a concern in the industry, however it should be excluded when assigning causality. Dosage is also important, as almost any substance, including water, can be dangerous with excessive dosing.  For example, Vitamin A has been cited to be a cause of liver damage, however in the primary case study, the patient was taking 500,000 units of Vitamin A per day, which is about 50 times the “high” dose of 10,000 units. 

History of Overreaction

Unfortunately, there is a long history of questionable research regarding the causality of botanical supplements to liver injury. Medical research authors have argued that in many cases, evidence of causation has been weak, lacking essential information, and failing to exclude many other possible causes of liver injury.

For example, prior to 1999, kava kava was considered a beneficial and exceptionally safe herb. There were at least 13 clinical studies showing kava’s positive effects and safety. Then suddenly there were at least 28 cases of suspected liver toxicity reported in Europe. The alarm bells went off with dire warnings in the media, and kava was banned in several countries.  Experts analyzing the reported cases found evidence of concomitant use of prescription medication, alcohol use, pre-existing liver disease, and excessive dosing. It turned out that a definite causal relationship could only be confirmed in one case. Controversy continued, until 15 years later the bans were lifted, and the consensus today is that “it is not clear whether kava itself causes liver damage, or whether taking kava in combination with other drugs or alcohol is responsible.”  However, cautions are advised, and kava should not be used by anyone who has any liver issues, is taking any prescription drugs, or anyone who is a regular consumer of alcohol.

Similarly, is the situation with black cohosh. Many clinical trials have shown black cohosh to be beneficial with no adverse events reported. However, cases began appearing in medical research, which claimed to link black cohosh to liver damage. There has been much controversy and debate over the quality of the evidence. For example, the European Medicines Agency reported 42 cases of liver injury attributed to black cohosh, yet their investigation showed the cases were poorly documented and concluded that only four cases could be classified as possible, or probable causes of liver injury. Other authors looked at those four cases and found even then that several of the patients were regularly consuming alcohol and taking several prescription drugs with well-known hepatotoxic effects. The current consensus is that liver damage from black cohosh is rare, “the evidence thus far strongly supports the overall safety” of black cohosh, and a minimal issue may be due to adulteration with the wrong plant species. 

Causality in the JAMA References

Given this history of controversy in assigning causality of liver damage to botanical supplements, we wanted to look deeper into the cases being referenced by this article. In the JAMA article itself which analyzes data from the NHANES survey, the authors noted that of the 5,271 HDS users, 3,725 (or 71%) of those were also taking more than one prescription drug (an average of 3) at the time.  Also, 2,664 HDS users (50%) were daily consumers of alcohol, 2,300 (44%) had hypertension and 1,109 (21%) had diabetes. All of these can cause or contribute to liver damage. Yet the authors imply that only the herbal dietary supplements are to blame for any risk of liver injury, while overlooking the possible contribution from prescriptions drugs and comorbidities.  

When looking into the Navarro study, we find similar evidence of other possible causalities being overlooked.  In the study that claims that liver injury from HDS has increased to “20%”, we find that of the 85 non-body building HDS users, the following “characteristics” apply: 22% diabetes, 11% heart disease, 28% gastrointestinal disease, and 54% alcohol use.  Again, all of these can contribute to liver damage, yet the HDS use alone is reported to be the cause.

 

We also checked the references for details on specific individual cases. This kind of investigation is difficult since journal articles do not always include detailed case information and often it requires following up on all the references. For ashwagandha and turmeric we were able to analyze 73 global case reports. We discovered that in 41 of the 73 cases, or 56%, the patients were taking multiple synthetic drugs at the same time and/or had pre-existing health conditions.  In many of these cases, the patients had multiple comorbidities such as diabetes, cancer, pre-existing liver disease, and hypertension, and were taking 4-8 prescription medications including statins, NSAIDS, and for women, progestins- all of which may cause or contribute to clinically apparent liver injury.

Also, we feel it is important to note that none of the individual cases we analyzed documented the patient’s weight or obesity (indicator of potential non-alcoholic fatty liver disease or other illnesses), or considered regular alcohol consumption as a potential risk. Case documentation also often lacked detailed information on the HDS used; the brand, ingredients, or dosage taken.

Blame Dietary Supplements but Prescription Drugs Get a Pass?

In doing this research we spent time reading individual cases and looking up both botanical supplements and prescription drugs in the LiverTox database which seems to be the primary authority on tracking drug causes of clinically apparent liver injury. We began to see a subtle pattern of downplaying the negative potential of prescription drugs, while inflating the causality of botanical supplements. 

One clear example of this was when we came across this case regarding ashwagandha in the literature: 

“The patient's medical history included arterial hypertension (long‐term treatment with phytotherapeutic product named Rauwolfia serpentina), psoriasis, and a status post‐tonsillectomy, without any records of complications. She reported no consumption of alcohol and no history of smoking. The patient traveled to the Mediterranean Sea for holidays 3 months before her presentation in the hospital. The patient experienced no physical symptoms, such as fever or gastrointestinal abnormalities during or following the holiday. She reported only a herpes labialis, which was treated by acyclovir orally. The only drug or toxin exposure in the patient's history prior to the admission that could explain the observed laboratory findings and the histological picture was ashwagandha.”

In this case any possible contributing factors from the pre-existing hypertension, herpes simplex, or use of acyclovir, all of which can contribute to liver injury, is disregarded and the only possible cause is said to be the ashwagandha.  When we looked up acyclovir in the LiverTox database, we found this:

From LiverTox: Acyclovir

“There have been rare instances of acute, clinically apparent liver injury reported that were attributed to acyclovir or valacyclovir (a prodrug of acyclovir with better oral absorption), but these have not been particularly convincing. Some degree of liver injury and even jaundice can occur during the course of herpes simplex infection, and these complications could be mistaken for drug induced liver injury. Furthermore, in the reported cases, patients were receiving other medications and had other underlying comorbidities that may have been responsible for the liver injury.”

So for acyclovir and other drugs, complications in assigning causality are acknowledged, and these are noted in the assessment to downplay possible causation from the drug, however such considerations are not made for botanical supplements, which are quick to be blamed. 

Death By Turmeric?

The JAMA study, the authors, and the media also claim that there have been fatalities due to liver damage from dietary supplements.  Making this claim without details or context can be very misleading and frightening to the public.  We looked to find the details regarding any cases of fatalities and could only find one that was publicly available on the LiverTox database.  In this case a 62 year old female patient had been taking turmeric for over a year as well as several other supplements, and 5 synthetic drugs.  She stopped taking turmeric and was diagnosed with liver disease; but her symptoms did not resolve on discontinuing the turmeric.  However, she then had a heart attack and died 13 days later.  The article did not discuss the possibility that the patient had undiagnosed congestive heart failure which can lead to liver failure.  The patient died of a myocardial infarction, yet the turmeric is listed as the only “probable” cause of death.   

 

How Supplements Compare to Drugs and Food

The research community and the media seem obsessed with reports about the dangers of dietary supplements. However, how does this compare to the dangers of prescription drugs and food? Ironically, there is no formal system for tracking injuries, hospitalizations, or death from drugs, foods, and supplements. Health providers and consumers are encouraged to report adverse drug reactions to the FDA which maintains two databases for adverse reports: FAERS for drugs and CAERS for food and supplements. Researchers will use this data or hospital admission studies to estimate adverse events.

 

Prescription and Over-the-Counter Drugs

A recent analysis estimates that 128,000 Americans die each year as a result of taking medications as prescribed. Nearly 60 to 70% of Americans take at least one prescribed drug.

Death by Tylenol – as it turns out, the greatest danger for liver injury is Tylenol, or acetaminophen. Acetaminophen toxicity is the most common cause of liver transplantation in the US and is responsible for 56,000 emergency room visits, 26,000 hospitalizations, and 500 deaths per year. 60 million Americans consume acetaminophen on a weekly basis.  

Non-steroidal anti-inflammatory (NSAIDs) drugs are even more dangerous- although to the stomach, instead of the liver.  30 million Americans take NSAIDs and the side effects of long-term use cause 103,000 hospitalizations and 16,500 deaths each year. 

Food

Even though America’s food supply is one of the safest in the world, the CDC reports that each year 48 million people get sick from foodborne diseases. This is equal to 1 out of 6 Americans or 16.6% of the population; 128,000 are hospitalized and 3,000 die each year from foodborne illness.

If we look at the FDA‘s list of reported recalls for consumer goods, it appears that food and beverages are far more dangerous than dietary supplements. From 2017 through 2024, 64% of recalls were for food and beverages, 20% for drugs and only 2.2% for dietary supplements. (The rest were for veterinary products, cosmetics or medical devices.)

So let’s compare the above reports to those of dietary supplements. Surveys that have analyzed adverse reports for HDS have suggested that there is an estimated average of 1,500 adverse reports, 400 hospitalizations, and 10-34 potential deaths from dietary supplements per year.  (These adverse reports for HDS include allergic reactions, unsupervised ingestion by children, excess dose, and choking on pills.)  When looking at the adverse event reports for 2023, there were 2,156,613 adverse reports for drugs. For the same year, there were 2,146 suspected adverse reports for dietary supplements- so more than 1,000 times the number of adverse reports for drugs.  The risk of death due to prescription drugs is 3,764 times that of dietary supplements (128K to 34). Also, it appears that your chance of being hospitalized from eating sandwich meat or ice cream is 288 times greater than the risk of taking turmeric or any dietary supplement.  From this data we wonder why there is not more attention from medical research and the media on the health risks of drugs and food, since they are both far more dangerous than dietary supplements.  

Are Cases Increasing?

As we discussed earlier, the JAMA article misleadingly implies that the incidents of liver injury from dietary supplements have increased from 7% to 20%. This is the reported ratio of HDS to drug related events in the last 10 years. This number is relative since we have no actual case numbers and all reporting is voluntary.  Also, we note that sales of supplements have been increasing at an annual average of 7.8% over the last 10 years, which considering the rate of sales increase, rates of liver injury may actually be going down.  In comparison, let’s look at the number of adverse events from the FAERS database for prescription drugs for the last few decades:  

 

It appears that the largest increase in adverse reports is coming from the pharmaceutical industry, not from supplements. 

A Threat to Big Pharma?

To understand the reason for all the hysteria over the safety of dietary supplements given the fact that they are actually much safer than the drugs and food you take in daily, we find a clue in the JAMA study, in the following quote:

 

“The economic impact of the HDS products industry in the US is profound, with over $150 billion in marketplace sales in 2023, and rivals that of all prescription drugs combined.” 

This statement is misleading and exaggerated. The reference to $150 billion in this article is an estimate of the overall economic impact of the dietary supplement industry, including jobs created and taxes collected, not sales alone.  The Nutrition Business Journal reports that dietary supplements sales were actually $63.5 billion in 2023.   Meanwhile, sales for the pharmaceutical industry for 2023 are reported to be between $429-$602 billion.  Another analysis of the overall economic impact of the pharmaceutical industry is reported as follows:

“The U.S. biopharmaceutical industry exceeded $800 billion in direct output in 2022, and with the ripple effect of this production throughout the U.S. economy, supported an additional $850 billion in output through its suppliers and other sectors of the economy, for a total of more than $1.65 trillion. This combined, total output impact represents 3.6 percent of all U.S. output.”

Therefore, the sales of HDS products do not “rival that of all prescription drugs combined”.  So again, as with the risks of injury, the sales of pharmaceuticals dwarf those of the supplement industry as the pharmaceutical industry is 6 to 12 times bigger than the supplement industry. Again, the JAMA article presents misleading information.  

The main point here is that it is obvious that Big Pharma is threatened by the supplement industry, and what they see as an erosion of their drug sales. And the corporate owned media, rather than checking the facts and doing the math, is willing to blindly follow the lead of big money.

Conflicts of Interest

Interestingly, the JAMA article itself continues to contradict its own claims and headlines and reveal the bias in their research.  It is rare that medical research articles offer transparency about conflicts of interest, however surprisingly, this article does so.  At the bottom of the article we learn that two out of the three authors are receiving grant money from five different pharmaceutical companies.  

Also, in one of the other research articles referenced by the JAMA article, we find that the two lead authors are working as consultants for and receiving grant money from several pharmaceutical companies.  We checked and one of these lead authors has written over 20 articles about the dangers of herbal supplements and liver injury and is also a main contributing author to the LiverTox database.  These are only a few conflicts that have been disclosed, but we suspect there are many more.   

 

Is the Supplement Industry Really Unregulated?

One of the biggest misrepresentations about the dietary supplement industry is that it is “unregulated”.  The JAMA article and all the media hype state this over and over again. However, this is just not true. Dietary supplements are actually highly regulated. From the FDA website:

“FDA regulates both finished dietary supplement products and dietary ingredients. FDA regulates dietary supplements under a different set of regulations than those covering "conventional" foods and drug products. Under the Dietary Supplement Health and Education Act of 1994 (DSHEA)…”

DSHEA granted the FDA powers to develop manufacturing standards for dietary supplements,  and passed the cGMP (Current Good Manufacturing Practices) final rule for supplements in 2007; these regulations are published in CFR 111 (Code of Federal Regulations) for all to see. cGMPs regulate manufacturing and are designed to ensure supplement quality and set standards for identity, strength, purity, and composition. The FDA also regulates labeling, health claims, documentation, specifications, sourcing, and training, just to mention a few. The FDA inspects domestic and foreign companies and conducts an average of 600 domestic audits of dietary supplement manufacturers annually. The agency is empowered to take enforcement actions such as issuing warning letters, product recalls and shutting down bad actors in order to protect public health.  

Dietary supplements are regulated at a higher standard than food, and at just a slightly lower standard than drugs. One of the primary differences in supplement and drug regulation is that drugs require “pre-market” approval. The pharmaceutical industry has in the past and continues today to lobby to have supplements regulated as drugs, and to require pre-market approval. However, supplements are not drugs, and they can’t be patented like drugs since most are made from natural sources.  In DSHEA, Congress correctly recognized decades of safe use of HDS and declared that existing dietary supplements were generally regarded as safe.  Only supplements containing “new dietary ingredients” that were not marketed in the United States before October 15, 1994, are subject to pre-market approval. 

Yet the JAMA article, Big Pharma, and the media continue to wrongly insist that supplements are drugs and should be regulated as such: “HDS products can be purchased without a prescription at various unregulated retail outlets or via the internet.” This is because Big Pharma could eliminate $63 billion worth of competition instantaneously if HDS were regulated as drugs. They know that the financial burden of lengthy and unnecessary drug level pre-market approval for each supplement, without the benefit of patents, would bankrupt most supplement companies. Big Pharma and their allies in the FDA already attempted to eliminate supplements this way in the early 90’s by classifying many supplements as drugs or food additives. This sparked one of the largest grassroots political movements in history which prevented their assault on health choice and resulted in the DSHEA regulations in 1994, which have protected our access to supplements for 30 years. 

 

 

Safe Supplement Use Tips

As we have briefly shown here, dietary supplements are actually profoundly safer than the drugs we take or the foods that we eat every day.  The risk of liver injury or adverse effects is truly uncommon and very minimal. 

However, as with any substance, there are some risks consumers should be aware of.  Certain supplements should be used with additional caution, or avoided, by those with existing liver injury or regular alcohol use. There may be unprincipled or careless manufacturers that result in contamination, adulteration, or wrong species used.  A small percentage of the population may have negative genetic or allergic responses to some herbs or supplements.  

Here are some suggestions for safe supplement use:

• Do not purchase the cheapest product. You get what you pay for. Following FDA regulations, using quality ingredients, and testing are all expensive and increase the cost of a quality product 
• Read labels, research ingredients and consult an herbalist or healthcare practitioner 
• Take the recommended dose on the label
• Avoid or use extra caution with weight loss and muscle building products since they are the most commonly adulterated products
• Avoid companies that make direct health claims using names of diseases (unless it is homeopathic); this means they are not following regulations and may also be less likely to follow cGMP requirements
• If you feel you react negatively to an herb or supplement, discontinue use and consult a healthcare practitioner
• Follow the caution that is on almost every dietary supplement label: If you are pregnant, nursing, taking medication or have a medical condition please consult a healthcare practitioner prior to use. 

Conclusion

While the headlines are telling us that 15 million Americans may be at risk of liver injury due to herbal dietary supplements, the data shows that the actual number of possible cases per year is around 10. And we have seen that many of these “potential” cases are based on incomplete documentation, and questionable causality assessments that downplay possible effects of comedications, comorbidities, and regular alcohol use. We agree with Steve Mister, president of CRN, when he said “Revealing that more than 15 million Americans use at least one of these herbal supplements, when compared to their actual reported risks, only strengthens the case for their safety.”

Meanwhile, the use of pharmaceuticals is doubling every decade with 50% of Americans taking multiple medications at the same time. Most recent studies indicate that the prevalence of non-alcoholic fatty liver disease has increased by 50% over the past few decades and as many as 42% of Americans may now be affected. And new studies show that even light or moderate alcohol use, not just excessive use, increases health risks including liver cancer.  Yet these real and increasing risks for liver injury are often ignored by researchers and the media, while undue blame is directed at the supplement industry.  

 

 

References

 

Newsweek. (2024, January 10). Health supplements like turmeric and green tea linked to liver damage. https://www.newsweek.com/health-supplements-turmeric-green-tea-liver-damage-1936581

 

Likhitsup A, Chen VL, Fontana RJ. Estimated Exposure to 6 Potentially Hepatotoxic Botanicals in US Adults. JAMA Netw Open. 2024;7(8):e2425822. doi:10.1001/jamanetworkopen.2024.25822

 

Medical News Today. (2024, August 18) 6 popular herbal supplements linked to potential liver risks. https://www.medicalnewstoday.com/articles/6-popular-herbal-supplements-green-tea-curcumin-linked-potential-liver-risks

 

American Botanical Council. (2024). JAMA paper exaggerates liver injury risk of several herbal dietary supplements. HerbalGram. https://www.herbalgram.org/news/press-releases/2024/jama-paper-exaggerates-liver-injury-risk-of-several-herbal-dietary-supplements/

 

Council for Responsible Nutrition. (2024). CRN responds to JAMA botanical use survey: Widespread use of herbal supplements confirms their safety. https://www.crnusa.org/newsroom/crn-responds-jama-botanical-use-survey-widespread-use-herbal-supplements-confirms-their

 

Navarro, V. J., Khan, I., Björnsson, E., Seeff, L. B., Serrano, J., & Hoofnagle, J. H. (2017). Liver injury from herbal and dietary supplements. Hepatology, 65(1), 363-373. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5502701/

 

Navarro, Victor J et al. “Liver injury from herbals and dietary supplements in the U.S. Drug-Induced Liver Injury Network.” Hepatology (Baltimore, Md.) vol. 60,4 (2014): 1399-408. doi:10.1002/hep.27317

 

Björnsson, E. S., Bergmann, O. M., Björnsson, H. K., Kvaran, R. B., & Olafsson, S. (2013). Incidence, presentation, and outcomes in patients with drug-induced liver injury in the general population of Iceland. Gastroenterology, 144(7), 1419–e20. https://doi.org/10.1053/j.gastro.2013.02.006

 

American Botanical Council. (2024). Herbal market report 2024. HerbalGram. https://umb.herbalgram.org/media/jk4f3rzm/hg141-hmr-web.pdf

 

National Institute of Diabetes and Digestive and Kidney Diseases. (2019). LiverTox: Clinical and research information on drug-induced liver injury. Ashwagandha.  National Center for Biotechnology Information. https://www.ncbi.nlm.nih.gov/books/NBK548536/

 

 

National Institute of Diabetes and Digestive and Kidney Diseases. (2019). Turmeric and curcumin. LiverTox: Clinical and research information on drug-induced liver injury. National Center for Biotechnology Information. https://www.ncbi.nlm.nih.gov/books/NBK548561/

 

National Institute of Diabetes and Digestive and Kidney Diseases. (2019). Causality assessment in drug-induced liver injury. LiverTox: Clinical and research information on drug-induced liver injury. National Center for Biotechnology Information. https://www.ncbi.nlm.nih.gov/books/NBK548049/

 

National Institute of Diabetes and Digestive and Kidney Diseases. (2019). RUCAM. LiverTox: Clinical and research information on drug-induced liver injury. National Center for Biotechnology Information. https://www.ncbi.nlm.nih.gov/books/NBK548272/

 

Teschke, R., Frenzel, C., Glass, X., Schulze, J. and Eickhoff, A. (2013), Herbal hepatotoxicity: a critical review. Br J Clin Pharmacol, 75: 630-636. https://doi.org/10.1111/j.1365-2125.2012.04395.x

 

Roerecke, M., Vafaei, A., Hasan, O. S. M., Chrystoja, B. R., Cruz, M., Lee, R., Neuman, M. G., & Rehm, J. (2019). Alcohol Consumption and Risk of Liver Cirrhosis: A Systematic Review and Meta-Analysis. The American journal of gastroenterology, 114(10), 1574–1586. https://doi.org/10.14309/ajg.0000000000000340

 

Hoofnagle, J. H., Bonkovsky, H. L., Phillips, E. J., Li, Y. J., Ahmad, J., Barnhart, H., Durazo, F., Fontana, R. J., Gu, J., Khan, I., Kleiner, D. E., Koh, C., Rockey, D. C., Seeff, L. B., Serrano, J., Stolz, A., Tillmann, H. L., Vuppalanchi, R., Navarro, V. J., & Drug-Induced Liver Injury Network (2021). HLA-B*35:01 and Green Tea-Induced Liver Injury. Hepatology (Baltimore, Md.), 73(6), 2484–2493. https://doi.org/10.1002/hep.31538

 

Centers for Disease Control and Prevention. (2022, March 11). Type 2 diabetes and liver disease. https://www.cdc.gov/diabetes/diabetes-complications/type-2-diabetes-liver-disease.html

 

Mayo Clinic. (2023, October 13). Autoimmune hepatitis: Symptoms and causes. https://www.mayoclinic.org/diseases-conditions/autoimmune-hepatitis/symptoms-causes/syc-20352153

 

GoodRx Health. (2023, May 5). The 10 worst medications for your liver. https://www.goodrx.com/health-topic/liver/the-ten-worst-medications-for-your-liver

 

Cheruvattath, R., Orrego, M., Gautam, M., Byrne, T., Alam, S., Voltchenok, M., Edwin, M., Wilkens, J., Williams, J.W. and Vargas, H.E. (2006), Vitamin A toxicity: When one a day doesn't keep the doctor away. Liver Transpl, 12: 1888-1891. https://doi.org/10.1002/lt.21007

 

American Botanical Council. (2002). Kava safety questioned due to case reports of liver toxicity. HerbalGram, 55. https://www.herbalgram.org/resources/herbalgram/issues/55/table-of-contents/article2147/

 

Kuchta, K., Schmidt, M., & Nahrstedt, A. (2015). German Kava Ban Lifted by Court: The Alleged Hepatotoxicity of Kava (Piper methysticum) as a Case of Ill-Defined Herbal Drug Identity, Lacking Quality Control, and Misguided Regulatory Politics. Planta medica, 81(18), 1647–1653. https://doi.org/10.1055/s-0035-1558295

 

Mount Sinai. (n.d.). Kava kava. https://www.mountsinai.org/health-library/herb/kava-kava#:~:text=More%20than%2030%20cases%20of,drugs%20or%20herbs%20is%20responsible.

 

Gori L, Firenzuoli F, Is black cohosh a hepatotoxic medicinal herb? Forsch Komplementärmed, 17 (2007), pp. 109-110

 

Rolf Teschke, Alexander Schwarzenboeck, Wolfgang Schmidt-Taenzer, Albrecht Wolff, Karl-Heinz Hennermann, Herb induced liver injury presumably caused by black cohosh: A survey of initially purported cases and herbal quality specifications, Annals of Hepatology, Volume 10, Issue 3, 2011, Pages 249-259, ISSN 1665-2681, https://doi.org/10.1016/S1665-2681(19)31536-4.

 

Firenzuoli, F., Gori, L., & Roberti di Sarsina, P. (2011). Black Cohosh Hepatic Safety: Follow-Up of 107 Patients Consuming a Special Cimicifuga racemosa rhizome Herbal Extract and Review of Literature. Evidence-based complementary and alternative medicine : eCAM, 2011, 821392. https://doi.org/10.1093/ecam/nen009

 

American Botanical Council. (2006). The safety of black cohosh in clinical studies. HerbalGram, 72. https://www.herbalgram.org/resources/herbalgram/issues/72/table-of-contents/article3039/

 

Centers for Disease Control and Prevention. (2022, March 11). Type 2 diabetes and liver disease. https://www.cdc.gov/diabetes/diabetes-complications/type-2-diabetes-liver-disease.html

 

Roerecke, M., Vafaei, A., Hasan, O. S. M., Chrystoja, B. R., Cruz, M., Lee, R., Neuman, M. G., & Rehm, J. (2019). Alcohol Consumption and Risk of Liver Cirrhosis: A Systematic Review and Meta-Analysis. The American journal of gastroenterology, 114(10), 1574–1586. https://doi.org/10.14309/ajg.0000000000000340

 

Tóth, M., Benedek, A. E., Longerich, T., & Seitz, H. K. (2023). Ashwagandha-induced acute liver injury: A case report. Clinical case reports, 11(3), e7078. https://doi.org/10.1002/ccr3.7078

 

Anderson, S. (2024, January 12). 6 popular herbal supplements, including green tea and curcumin, linked to potential liver risks. Medical News Today. https://www.medicalnewstoday.com/articles/6-popular-herbal-supplements-green-tea-curcumin-linked-potential-liver-risks

 

National Institute of Diabetes and Digestive and Kidney Diseases. (2019). Turmeric and curcumin. LiverTox: Clinical and research information on drug-induced liver injury. National Center for Biotechnology Information. https://www.ncbi.nlm.nih.gov/books/NBK548561/

 

Esposito, L. (2016, September 27). The danger in taking prescribed medications. U.S. News & World Report. https://health.usnews.com/health-news/patient-advice/articles/2016-09-27/the-danger-in-taking-prescribed-medications

[The above article was removed and replaced during the time our investigation took place, the below redirected Google listing still exists, article can still be found on Yahoo]

 

Los Angeles Times. (1998, April 15). Medications Kill 100,000 Annually, Study Says.  https://www.latimes.com/archives/la-xpm-1998-apr-15-mn-39509-story.html

 

National Institute of Diabetes and Digestive and Kidney Diseases. (2017). Acetaminophen toxicity. LiverTox: Clinical and research information on drug-induced liver injury. National Center for Biotechnology Information. https://www.ncbi.nlm.nih.gov/books/NBK441917

 

University of North Carolina at Chapel Hill. (2005, January 11). Over-the-counter painkiller is leading cause of acute liver failure, study finds. ScienceDaily. https://www.sciencedaily.com/releases/2005/01/050111123706.htm

 

U.S. Department of Agriculture. (n.d.). How many foodborne illnesses occur each year? https://ask.usda.gov/s/article/How-many-foodborne-illnesses-occur-each-year

 

U.S. Food and Drug Administration. (n.d.). Recalls, market withdrawals & safety alerts. https://www.fda.gov/safety/recalls-market-withdrawals-safety-alerts

 

U.S. Food and Drug Administration. (n.d.). CFSAN adverse event reporting system (CAERS). https://www.fda.gov/food/compliance-enforcement-food/cfsan-adverse-event-reporting-system-caers

 

U.S. Food and Drug Administration. (n.d.). FDA adverse event reporting system (FAERS) public dashboard. FDA.gov

 

Council for Responsible Nutrition. (2016). CRN report: Dietary supplement companies pump more than $158 billion into the U.S. economy. https://www.crnusa.org/newsroom/crn-report-dietary-supplement-companies-pump-more-158-billion-us-economy-23-2016

 

Nutraceuticals World. (2024). Dietary supplement market grows again after post-COVID normalization. https://www.nutraceuticalsworld.com/exclusives/dietary-supplement-market-grows-again-after-post-covid-normalization/

 

IQVIA Institute. (2023). The use of medicines in the U.S. 2023. https://www.iqvia.com/insights/the-iqvia-institute/reports-and-publications/reports/the-use-of-medicines-in-the-us-2023

 

BioSpace. (2024). U.S. pharmaceutical market size to reach USD 1.09 trillion by 2033.

 

Pharmaceutical Research and Manufacturers of America. (2024). Industry economic impact.

 

Navarro, V. J., Bonkovsky, H. L., Hwang, S. I., Vega, M., Barnhart, H., & Serrano, J. (2013). Catechins in dietary supplements and hepatotoxicity. Digestive diseases and sciences, 58(9), 2682–2690. https://doi.org/10.1007/s10620-013-2687-9

 

U.S. Food and Drug Administration. (n.d.). Dietary supplements. https://www.fda.gov/food/dietary-supplements

 

Natural Products Association. (n.d.). Dietary supplements: How foods became regulated. https://www.npanational.org/resource/dietary-supplements-foods-became-regulated/

 

U.S. Government Publishing Office. (n.d.). Current good manufacturing practice in manufacturing, packaging, labeling, or holding operations for dietary supplements (21 CFR Part 111).

 

R. William Soller PhD, Holly J. Bayne, Christopher Shaheen; “The Regulated Dietary Supplement Industry: Myths of an Unregulated Industry Dispelled” American Botanica Council Herbalgram ISSUE: 93 Page: 42-57 

 

Supply Side Supplement Journal. (2025) FDA in 2025: Navigating changes in food and dietary supplement investigations

Teschke R, Frenzel C, Glass X, Schulze J, Eickhoff A. Herbal hepatotoxicity: A critical review. Br J Clin Pharmacol. 2013;75(3):630-636.

 

Zhong, Wenjun et al. “Age and sex patterns of drug prescribing in a defined American population.” Mayo Clinic proceedings vol. 88,7 (2013): 697-707. doi:10.1016/j.mayocp.2013.04.021

 

Díaz, L.A., Lazarus, J.V., Fuentes-López, E. et al. Disparities in steatosis prevalence in the United States by Race or Ethnicity according to the 2023 criteria. Commun Med 4, 219 (2024). https://doi.org/10.1038/s43856-024-00649-x

 

Today. (Jan. 25, 2025) Is any amount of alcohol safe? Here’s what 8 doctors actually tell their patients https://www.today.com/health/behavior/drinking-alcohol-doctors-recommendations-rcna188526

 

 

Additional References

Anke, J., & Ramzan, I. (2004). Kava hepatotoxicity: Are we any closer to the truth? [PDF]

Planta Medica, 70(3), 193-196. https://doi.org/10.1055/s-2004-815533

 

Coulter, D., Tamayo, C., Sotheeswaran, S., & Ulbricht, C. (2007). Assessment of the risk of

 hepatotoxicity with kava products [PDF]. World Health Organization.

https://iris.who.int/bitstream/handle/10665/43630/9789241595261_eng.pdf

 

Dog, T. L., Powell, K. L., & Weisman, S. M. (2003). Critical evaluation of the safety of Cimicifuga racemosa in menopause symptom relief. The Journal of the North American Menopause Society, 10(4), 299-313. https://doi.org/10.1097/01.GME.0000056039.51813.21

 

Huntley, A., & Ernst, E. (2003). A systematic review of the safety of black cohosh. The Journal of the North American Menopause Society, 10(1), 58-64. https://journals.lww.com/menopausejournal/abstract/2003/10010/a_systematic_review_of_the_safety_of_black_cohosh.10.aspx

 

Lombardi, N., Crescioli, G., Maggini, V., Ippoliti, I., Menniti‐Ippolito, F., Gallo, E., Brilli, V., Lanzi, C., Mannaioni, G., Firenzuoli, F., & Vannacci, A. (2021). Acute liver injury following turmeric use in tuscany: An analysis of the italian phytovigilance database and systematic review of case reports. British Journal of Clinical Pharmacology, 87(3), 741-753. https://doi.org/10.1111/bcp.14460

 

Philips, C. A., Valsan, A., Theruvath, A. H., Ravindran, R., Oommen, T. T., Rajesh, S., Bishnu, S., & Augustine, P. (2023). Ashwagandha-induced liver injury—A case series from india and literature review. Hepatology Communications, 7(10). https://doi.org/10.1097/hc9.0000000000000270

  

Teschke, R., Schwarzenboeck, A., Schmidt-Taenzer, W., Wolff, A., & Hennermann, K.-H. (2011). Herb induced liver injury presumably caused by black cohosh: A survey of initially purported cases and herbal quality specifications. Annals of Hepatology, 10(3), 249-259. https://doi.org/10.1016/s1665-2681(19)31536-4