Updated 19th November 2025
Are dietary supplements linked to a rise in liver damage?
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If you’ve looked around a grocery store, followed influencers on social media, or listened to any podcasts in the last few years, you will have likely noticed the meteoric rise in supplements.
In 1994, approximately 4,000 dietary supplement products were available. That figure is now approximately 100,000 in the United States alone.
Similarly, in 2021, the global supplement industry was valued at $152 billion, and it is projected to reach $300 billion by 2028.
In fact, in the United States, the supplement industry has grown 10-fold from $4 billion in the 1990s to $40 billion in 2019.
Fifteen years ago, there was little more than vitamin supplements available. Now, you can find supplements specific for babies, toddlers, kids, adults, older adults, people going through menopause, and so on and so on.
Unlike medicines, which are tightly regulated, the laws governing supplement manufacturers are, at best, incredibly limited. This means that the quality and safety of products are never guaranteed.
Although it is illegal for supplement manufacturers to claim that their product can treat or prevent specific diseases (because there’s no evidence that they can), they are allowed to use misleading, wishy-washy claims, like “supports overall wellness” and “provides immune support.”
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In this article, we won’t be delving into the debate about whether supplements work or not; we’ve covered that elsewhere.
Here, we’ll specifically investigate whether the uptick in supplement usage is linked to a parallel rise in liver damage.
If you’d like to learn more about specific supplements, try these podcast episodes:
Which supplements work, and which are a waste of money, with Prof. Tim Spector and Prof. Sarah Berry.
Do you really need to take omega-3 supplements? With Prof. Sarah Berry.
The truth about vitamin supplements with Prof. JoAnn Manson and Prof. Sarah Berry.
Should you take vitamin D supplements? With Prof. Tim Spector and Prof. Sarah Berry.
Before we get into it, we should make it clear that liver damage due to supplements may be on the rise, but it is still very rare.
Rather than scaremongering, we simply want to highlight that supplements are not the hassle-free route to health that they claim to be.
What’s your liver got to do with it?
Your liver is a wonderful organ. It carries out literally hundreds of functions, many of which revolve around detoxification.
The liver contains a vast suite of enzymes that help it neutralise toxins before moving them on to your kidneys to be passed in urine.
It’s the reason you don’t actually need to use detoxes — that’s your liver’s job.
However, despite your liver’s hi-tech detoxification powers, if it is overworked, it can start to fail. This is why excessive alcohol (a genuine toxin) can lead to liver damage and eventually failure.
Supplements, including “natural” herbal products, can also cause liver damage if consumed in large amounts or if they contain chemicals that they shouldn’t.
Supplements and liver damage in numbers
In 2004, 7% of all drug-induced liver injuries were caused by dietary supplements. In 2013, it was up to 20% — that’s 1 in 5.
According to the authors of a review on the topic, “Many of those cases required hospitalization, others required liver transplantation, and some resulted in death.”
They explain that these injuries were generally caused by:
Untested plant extracts.
Combinations of extracts.
Poorly researched novel dietary ingredients.
Manufacturers intentionally adding approved or unapproved drugs.
Worryingly, some research suggests that certain forms of liver injury caused by herbal supplements may be more severe than that caused by regular medications, more frequently ending in death or a liver transplant.
‘Natural’ herbal supplements
Many supplements claim to include “natural ingredients,” such as herbs and other botanical extracts.
Putting “natural” on a label helps it sell. This is because we automatically equate “natural” with “healthy” or “safe,” but that’s not necessarily true.
Because we are tricked into thinking they are safe, we might also assume that we can take as many as we want and that more is always better.
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This is also untrue. Even some essential micronutrients, like vitamin A, can cause real harm if taken in excess. Your biology is all about balance.
Another issue is that herbal supplements often contain a cocktail of phytochemicals. Even if each one is safe when taken in isolation, we often have no idea how they will behave when taken in combination.
As the authors of one review write:
“Botanical dietary supplement formulations often contain myriad phytochemicals — in a concentrated form — many of which had never been ingested in combination before the marketing of the product.”
Case study 1: OxyELITE Pro
In Hawaii in 2013, there was an outbreak of severe acute hepatitis (an inflamed liver) that affected 36 people. These individuals had all been taking a weight-loss and muscle-building supplement called OxyELITE Pro.
Tragically, one person died, and two others needed a liver transplantation.
The others slowly recovered, but some developed an autoimmune hepatitis-like condition. The drug was removed from sale.
Although the researchers could not definitively prove the cause of this outbreak, they believe it may have been because the manufacturers had added aegeline in March 2013.
Aegeline is extracted from the fruit of the Bengal quince tree and has been used by Ayurvedic practitioners for centuries.
Experts are still unsure why it had such a devastating effect on these individuals.
Other issues
Another ingredient commonly added to dietary supplements is caffeine, the most commonly used psychoactive drug in the world.
While safe for most people in the doses found in coffee and tea, it can cause harm in larger amounts.
More worryingly, caffeine is known to interact with other phytochemicals, potentially increasing the likelihood of damage to the liver and cardiovascular symptoms.
Other seemingly benign compounds can also cause trouble in some cases. Green tea is incredibly popular in many Asian countries and is generally considered healthy.
However, in its concentrated powdered form, there is some evidence from animal studies that it may be toxic to the liver.
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As we mentioned, legislation controlling the supplement industry is much more lax than it is for medications.
For instance, one report found that more than 50% of all supplement manufacturing facilities inspected by the U.S. FDA were non-compliant on at least one aspect of the Good Manufacturing Practices guidelines, which were set up to ensure products are safe.
At the same time, raw materials for dietary supplements often come from countries where there are much less stringent controls on farming practices, increasing the risk that they might be contaminated with pesticides or heavy metals.
How often these factors directly influence liver health is difficult to track, but the National Center for Complementary and Integrative Health warns of the possibility.
Case study 2: The COVID-19 effect
As COVID-19 shut nations down and spread fear across the world, many people turned to supplements. In particular, there was an uptick in sales of “immune boosters,” for obvious reasons.
One such supplement was linked to a hepatitis-like outbreak.
Fewer people were affected than in the Hawaiian example above, with six people needing medical care.
The supplement in question, which is also used in Ayurvedic medicine, comes from a shrub called heart-leaved moonseed (Tinospora cordifolia).
Experts are still unsure why this extract caused such a poor reaction in these individuals.
One theory is that it exacerbated an existing autoimmune liver disease that the patients were unaware of.
Summary
As we mentioned earlier, liver damage caused by supplements is still rare considering the size of the market.
However, the take-home message is this: Just because something says it will “support your health” and contains “all natural ingredients” doesn’t mean it will really benefit you, and it doesn’t mean it is 100% safe.
At ZOE, we believe that food is more than enough. Unless your doctor has recommended a supplement, you probably don’t need one.
If you eat a diverse diet that contains plenty of colourful fruits and veg, nuts and seeds, and beans and pulses, you should have everything you need.
If you’d like more advice about how to eat for a longer, healthier life, try reading these next:
