Some popular wellness supplements have documented links to liver injury. Here’s what experts want you to know before you add one to your routine.
Reviewed by Dietitian Lisa Valente, M.S., RD
Key Points
- Supplements can be part of a healthy routine, but they can also be risk for your liver.
- Because the liver breaks down supplements, it can be damaged by certain nutrients.
- Talk to your healthcare provider and test your levels before starting a new supplement.
Taking a daily supplement can be a healthy habit, but not always. Many people don’t realize that some popular products on store shelves today can put strain on the liver, one of the body’s hardest-working organs.
Every supplement you take is processed through the liver before it reaches the rest of your body. “Many medications and supplements can interfere with how the liver breaks things down, causing changes in metabolism and potentially resulting in severe health consequences,” says Resham Ramkissoon, MD..
Herbal and dietary supplements now account for more than 16 percent of drug-induced liver injury cases in the United States, a number that has been rising steadily. Below, experts break down which supplements are most commonly linked to liver harm and what to do instead.
1. Green Tea Extract
Drinking a cup of green tea is different from taking it in a concentrated supplement form. Green tea extract has been linked to more reported cases of liver injury than almost any other herbal supplement, according to U.S. drug-induced liver injury data.
The culprit is EGCG (epigallocatechin-3-gallate), the main active catechin in green tea. In supplement form, a single capsule can deliver three to four times the EGCG found in a brewed cup. “The European Food Safety Authority has identified 800 mg of EGCG per day as the threshold where liver enzyme elevations become a measurable concern,” says Sammy Peterson, M.S., RDN., “And most people taking it for weight loss are not stopping at one capsule.”
If you want the antioxidant benefits of green tea, drinking it as a beverage is a safer approach than reaching for a concentrated capsule.
2. High-Dose Vitamin A
Vitamin A is essential for vision, immune function, and cell health, and it’s a common ingredient in multivitamins and standalone supplements. But unlike water-soluble vitamins such as vitamin C or the B vitamins, your body doesn’t simply flush out the excess.
“Vitamin A is fat-soluble, meaning your body stores what it doesn’t use rather than excreting the excess, and over time, too much can cause toxicity, inflammation, and even progress to fibrosis,” says Peterson. Jay Luthar, MD. adds, “the tolerable upper limit for adults is 3,000 mcg RAE (10,000 IU) per day from all sources combined.” In severe, long-term cases, this can lead to liver damage, including fatty buildup, fibrosis and cirrhosis, which may be irreversible.
The good news is that many people are already meeting their vitamin A needs through diet. Eggs, dairy and orange and yellow vegetables are all rich sources. “Many people are already getting adequate vitamin A through food, so supplementing on top of that without knowing your levels is where things go wrong,” Peterson adds.
3. Turmeric Extract with Black Pepper
Turmeric has become one of the most popular supplements on the market, driven by its reputation as a natural anti-inflammatory. But the supplement form, particularly when paired with black pepper extract, behaves very differently from the spice you use in cooking.
“Turmeric extract combined with black pepper is one of the more well-documented supplement-related liver concerns we have right now,” says Jill McNutt, M.S., RDN. “The research shows that piperine, the active compound in black pepper extract, inhibits the liver’s ability to break down curcumin, which drives it to potentially toxic levels.” Although black pepper helps with curcumin absorption, the extract combined with supplemented doses can prove harmful.
Turmeric-associated liver injury cases have been increasing, with 6 of the 10 cases tracked by the national Drug-Induced Liver Injury Network occurring since 2017, including one death from acute liver failure. If you want the anti-inflammatory benefits of turmeric, using it as a food spice in curries, soups, or smoothies is a safer option than a high-potency extract.
4. Donuts
Many people take ashwagandha for stress relief, sleep support, or general wellness. While it is widely considered safe at typical doses, there have been several documented reports of ashwagandha-related liver injury in the U.S. and internationally, including at least one case requiring a liver transplant.,
“The precise toxic threshold isn’t established, but reported cases tend to involve daily doses well above the traditional Ayurvedic range of 3 to 6 grams of root powder.” says McNutt.” If you’re taking ashwagandha and notice symptoms like fatigue, nausea, dark urine, or yellowing of the skin or eyes, stop taking it and check in with your doctor right away,” she adds.
If you are drawn to ashwagandha for stress or sleep, speaking with your healthcare provider before starting is a reasonable first step, particularly if you take other medications or have any history of liver issues.
Tips for Choosing Supplements Safely
Supplements are generally not required to prove safety or efficacy before hitting store shelves, which puts some responsibility on consumers to make informed choices. Here is what experts recommend:
- Get your labs checked first. “Test, don’t guess,” says Peterson. “Before starting any new supplement, especially fat-soluble vitamins like A, D, E, and K, get your levels checked so you know whether you actually need them.” “The best use of supplements is to correct nutritional deficiency and the evidence is strongest there,” says Luthar. Supplementing without a confirmed deficiency can mean adding to levels that are already where they need to be.
- Look for verification. Because supplements are not FDA-approved before sale, look for seals from NSF International, USP or Informed Sport. These confirm the product contains what the label claims, at the stated dose, without unlisted contaminants.
- Prioritize food first. For most commonly supplemented nutrients, food sources deliver meaningful benefits without the concentrated doses associated with liver harm. “Supplements should supplement an already solid foundation, not replace one,” says Peterson.
- Talk to your healthcare team. “Most liver damage from supplements is entirely preventable,” says Peterson. This matters especially with underlying health conditions. “Patients should always consult with their doctor before starting a new supplement,” says Ramkissoon.
Our Expert Take
Some of the most popular supplements on store shelves today, including green tea extract, high-dose vitamin A, turmeric extract with black pepper, and ashwagandha, have documented links to liver injury. That does not mean supplements are universally dangerous, but it does mean they deserve more scrutiny than most people give them. Dose is also extremely important. Confirm you actually need it, choose a tested product and tell your doctor.
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