Supplement safety
Can Your Supplements Hurt Your Liver?
Reviewed by a qualified clinician · analysed at UKAS-accredited UK labs (ISO 15189)
Last reviewed July 20267 min read
Every Helvy guide is written by our health editors, then checked by a qualified clinician before it goes live and re-checked as the science moves. We name clinical roles, not individuals, until each reviewer has agreed to be credited publicly. This is wellness guidance to help you understand your own data, not a diagnosis.
QUICK ANSWER
Rarely, yes. Turmeric, green tea extract and ashwagandha have all been linked to reported cases of liver injury. The reaction is idiosyncratic, so it hits a small number of people and is hard to predict. It often starts with no symptoms at all. A liver blood test measuring ALT and ALP is the early read.
Find the test that fits your stack →As of July 2026. This is a live question in the UK. The Food Standards Agency has asked the Committee on Toxicity to review herb-induced liver injury, and a discussion paper went to the Committee on 6 July 2026. It is a paper for discussion, not a Committee verdict. Every figure below is cited.
You take turmeric for your joints. Green tea extract because it was in the fat-loss stack. Ashwagandha because sleep got bad. All three are sold as gentle, natural, basically food. For most people they pass through without incident. For a small number, they do not.
1. Which supplements are actually implicated?
Three names come up again and again in the case literature: turmeric or curcumin, green tea extract, and ashwagandha. Garcinia cambogia, red yeast rice and black cohosh follow behind them.
Green tea extract has the longest record. The NIH LiverTox database is the reference catalogue for supplement liver harm, and it rates green tea extract as a well established cause.
“More than 100 instances of clinically apparent liver injury attributed to GTE have been reported in the literature.”
— NIH LiverTox, Green Tea (GTE = green tea extract)
Turmeric now carries the same top likelihood score on LiverTox, updated in June 2025. Ashwagandha sits a step below, with five published cases of liver injury. Three were collected in Iceland and two by the US Drug-Induced Liver Injury Network.
The scale of exposure is what makes rare interesting. A 2024 survey study in JAMA Network Open put 4.7% of US adults on at least one of these six botanicals in the past 30 days. That is an estimated 15.6 million people. Turmeric led the list, then green tea, then ashwagandha.
The share of liver injury traced to supplements is also climbing. In the US network above, supplements went from 7% of cases in 2004 to 19% by 2012. This is not a new worry, either. The UK banned kava kava in medicines back in 2003 after reports of serious liver toxicity.
2. Why does it hit some people and not others?
Because the reaction is idiosyncratic. That is the clinical word for unpredictable. It is not simply a case of taking too much, and there is no dose that is safe for everyone.
The Committee on Toxicity made that point in its 2024 statement on turmeric. It found that turmeric at the levels found in supplements may pose a risk to the liver in rare individuals, even at intakes below the acceptable daily intake of 0 to 3 mg per kg of body weight. Genetics look to be part of it. One susceptibility gene variant, HLA-B*35:01, has been flagged. Nobody knows they carry it before something goes wrong.
Two things do raise your odds, though, and both are worth knowing.
- —Enhanced absorption formulas. Many turmeric products add piperine, from black pepper, to push more curcumin into the blood.
- —Stacking. Multi-ingredient products and several supplements at once make the culprit almost impossible to name later.
Existing liver problems, heavy drinking and certain medicines all add to the load your liver is already carrying. If any of those apply, talk to a qualified clinician before adding a botanical.
3. What are the warning signs, and when do they appear?
Here is the uncomfortable bit. Liver injury can range from raised enzymes with no symptoms at all, right through to serious illness. The quiet end is the common end. You feel completely fine while your numbers drift.
When symptoms do arrive, they are rarely quick. LiverTox reports that for turmeric, the time from starting to injury ranged from a few weeks to eight months, and was typically one to four months. That delay is exactly why people fail to connect the two.
Signs worth acting on, per the NHS:
- —Yellowing of the skin or the whites of the eyes.
- —Itchy skin, dark urine or pale stools.
- —Unusual tiredness, nausea or pain under the right ribs.
Any of those means stop the supplement and see a doctor promptly. Do not wait for a test. In the published ashwagandha cases, jaundice and itching were the usual presentation, and liver tests settled again over one to five months once the supplement stopped.
4. Which blood markers actually move?
Liver injury shows up on standard bloods before it shows up on you. Two enzymes carry most of the signal, and two proteins tell you how well the liver is doing its day job.
| Marker | What it tells you |
|---|---|
| ALT | An enzyme held inside liver cells. It leaks into the blood when those cells are irritated, so it rises early. |
| ALP | Alkaline phosphatase. It points at the bile ducts, the pattern seen in the ashwagandha cases. |
| Albumin | A protein the liver makes. It reflects how the liver is functioning rather than whether it is inflamed. |
| Total protein | The wider protein picture, read alongside albumin. |
ALT is the cheap early read, and the one most worth having a baseline for. Our ALT blood test guide covers the ranges and what a mild rise usually means. A hospital liver panel also includes AST, GGT and bilirubin, which our home panel does not measure. The liver function test guide explains the full set.
One caution on timing. A blood test measures biomarkers and offers wellness insight. It does not diagnose liver disease, and a single mildly raised ALT is common and often means nothing. A qualified clinician should read your numbers in context.
5. What to do if you take one of these
None of this makes turmeric a villain. It makes it a substance worth treating with the same respect as anything else you swallow daily. The same goes for the botanicals sold as liver support, which is a claim with far less behind it than most buyers assume. Our guide to dandelion root and the liver detox claim works through the evidence. Four sensible habits:
- —Get a baseline before you start a new botanical, then recheck a few months in.
- —Add one thing at a time, so a change in your bloods has an obvious owner.
- —Stick to label doses, and be wary of enhanced absorption claims.
- —Report a suspected reaction through the MHRA Yellow Card scheme.
Helvy’s Thyroid & Vital Organs panel (£159) measures ALT, ALP, albumin and total protein, alongside thyroid, kidney and cholesterol markers, from a home finger-prick sample. Results come back in about five working days from UKAS-accredited UK laboratories.
Worth knowing too: some supplements skew results rather than harm you. Our guide on supplements that affect blood tests covers what to pause before you draw. The metabolic health hub maps the wider organ picture.
READY TO TEST?
Check the quiet end before it gets loud
Helvy’s Thyroid & Vital Organs panel reads ALT, ALP, albumin and total protein together with your thyroid and kidney markers, so you see the whole organ picture rather than one number. Results in about 5 working days.
Frequently asked questions
Is turmeric bad for your liver?
For most people it causes no problem. Rare cases of liver injury have been reported, and the NIH LiverTox database now rates turmeric a well documented cause. The UK Committee on Toxicity noted in 2024 that the reaction can happen even below the acceptable daily intake, because it is idiosyncratic.
Does drinking green tea carry the same risk?
The cases involve concentrated green tea extract, not the brewed drink. Extracts deliver far more catechins per dose than a cup of tea. Fat-loss and multi-ingredient products are where extract usually turns up.
Should I get a blood test before starting ashwagandha?
A baseline helps. Without one, a raised ALT months later is hard to interpret, because you cannot tell whether it is new. Our ashwagandha side effects guide covers the thyroid and sedation questions too.
How long after stopping do liver tests recover?
In the published ashwagandha case series, liver tests normalised within one to five months of stopping. Recovery varies by person and by how much injury occurred. This is general information rather than medical advice, so let a qualified clinician guide your follow-up.
Related guides
Liver Function Test UK
What ALT, AST, ALP, GGT and bilirubin each measure.
ALT Blood Test UK
The early enzyme, its ranges, and what a mild rise means.
Ashwagandha Side Effects
Sleep, thyroid, liver and who should be careful.
Supplements That Affect Blood Tests
What to pause before a draw, so your results read true.