Ashwagandha is one of the most popular adaptogens—but is it safe? We dive into the science, adulteration risks, and liver concerns to separate fact from fear.
Hey there, Christophe from TheFrenchHerbal.
A few weeks ago, I attended an herbal conference here in France. And an independent lab presented a new way to determine what’s in a dried herbal extract. I don’t know if you’ve ever seen a concentrated herbal extract; it looks like a very fine powder. That’s all you can see. So we lost any visual clue to what’s in there. Some are of great quality, of course. And as we saw during the conference, some were pretty concerning, even appalling.
Even supplements coming from well-known and respected labs were of poor quality. Not all of them, of course, but some of them. Enough to make us all, in the audience, uncomfortable.
Why is that? Because the market for dried and concentrated extract is pretty murky. Labs buy from wholesalers, who buy from other labs, who buy from other wholesalers. And sure, they can show you some kind of traceability. But in the end, you get a powder that looks like any other powder. Supplement companies usually have to ask for chromatography or other types of analysis, but this is not sufficient.
What we heard during the conference is that when you use advanced identification techniques, you see that some powders do not contain enough active substances. Some contain substances that do not belong here at all. For instance, some ashwagandha products contained traces of Viagra. Not good.
Which brings me to today’s topic. You may have heard that, based on recent scientific evidence, ashwagandha is not a safe herb because it might injure your liver. In this episode, I would like to shed some light on the situation. Because what’s emerging in the literature is actually pretty subtle, complex… and easy to misunderstand. I will try to simplify the situation while delivering the important points. Above all, I’d like to separate fact from fear, especially if you have seen those sensational headlines “Ashwagandha is Toxic to Your Liver” or similar.
Here is what you will find in this episode:
The episode is indexed, so if you want to jump directly to the practical recommendations at the end, you can. Although if I made this into a long format, it is because I would like you to fully understand what’s involved. So I hope you take the time to fully explore the issue at hand; it orbits around ashwagandha but several points are generic to the overall herbal business.
Before we start, a quick but important reminder: I am not a doctor, pharmacist, or licensed healthcare professional. The information shared in this episode is for educational and informational purposes only. It is not intended to diagnose, treat, or cure any condition, and it does not replace professional medical care. Always consult your physician before starting any new herbal protocol, especially if you are pregnant, nursing, or taking medication.
First of all, you should know that I am biased. I am. And you are. We all are. We all have our biases. Mine is that I have trust in herbal medicine. But I keep reminding myself that if I want to do a good job, I must be willing to contradict my own beliefs. I must be able to accept that:
We also need to see when scientific evidence is not trustworthy enough, because the product may have been adulterated with plant parts that do not belong in the product. Ashwagandha will be in that category as well.
OK, that being said, let’s start with the big picture. Ashwagandha (Withania somnifera) is one of the most widely used herbs in modern herbal practice. It comes from ayurvedic medicine; it has thousands of years of use behind it. It is a cornerstone adaptogen (I will make an episode on the “adaptogen” term because, well, we need to spend some time on that).
Ashwagandha is used in most Western countries now. We have been cultivating it locally in France for a few years and getting good results from organic, ethical, and local sources of the plant.
And here is an important point: historically, it has a strong reputation for safety.
But over the past decade, we have started to see increasing reports of liver injury, leading to more scrutiny from researchers and growing pressure from regulatory authorities in some countries.
We need to get to the bottom of those liver injury issues.
But before we zoom in on ashwagandha and the liver, it’s important to understand the broader context.
The herbal field has been dealing with liver safety concerns for decades. There have been repeated cases where herbs were suspected of liver toxicity. But the cases are challenging to make due to delayed symptoms. You see, liver toxicity can be quick, but it can also be slow and insidious.
We saw some issues with kava, turmeric extract, black cohosh. And if you look at the case reports, they are a mess because the case history lacks information on how long the person took the plant and the exact composition of the product. Sometimes, the product is a multi-herbal formula, and we implicate one herb, which doesn’t make sense. Sometimes the person is also taking a long list of drugs for heart, metabolic, autoimmune, thyroid issues, etc. Some people have a history of alcohol abuse. So it’s a huge mess. And we are concerned that within that mess, the herb will be guilty by default.
But again, on the other hand, we have to be willing to accept that it could be implicated as well.
Anyway, I just wanted to give you that larger context because we have been dealing with those “accusations” for quite a while. And most of the time they are far from black and white. But back to ashwagandha.
Since around 2017, a cluster of reports began to emerge in the US, Iceland, and Japan, all suggesting a possible link between ashwagandha and liver injury (Björnsson 2020; Inagaki 2017). The references are on my website.
But the most significant development came in 2023, and it was what we call a “case series” from India. (Philips 2023). Which means they included several case reports in the same study.
Researchers reviewed medical records from three hospitals over four years. They initially identified 23 suspected cases.
Then they removed what we call “confounding factors”: alcohol use, other medications or herbs, and alternative causes of liver disease.
And they retained 8 cases where ashwagandha was the likely factor. Ages ranged from 31 to 75 years old. Some had diabetes or hypertension. Several had pre-existing liver disease.
Of those 8 cases:
So, a critical point here: all problems occurred in patients with pre-existing liver disease. It seems that ashwagandha made the situation worse.
At the macro level, the symptoms were jaundice, itching, fatigue, and unfortunately death for the 3 cases.
At the micro level, there was inflammation of the portal vein, infiltration of the immune system in the cells of the liver, and hepatocellular necrosis (so necrosis of the liver cells) in about half the cases.
This is consistent with what we call “drug-induced liver injury”, or DILI. Meaning we are pretty sure that in those 8 cases, the reaction was to the ingestion of ashwagandha, which behaved as a liver irritant, or, to use a stronger word, a liver intoxicant.
One of the key features of DILI is a delayed onset. The reaction took a few weeks to over a year to appear, to become symptomatic. This is important because it strongly suggests that we are NOT dealing with direct toxicity, but something else.
And here, to take a step back, it’s good to remind ourselves that when we ingest a substance, there are two main types of liver toxicity.
The first one is a direct toxicity. It is rapid, dose-dependent, and quite predictable. If you test that substance on poor animals, for instance, you will see that they quickly get sick in a predictable manner. If you give them more, they will get more ill and eventually die. That is not what happened here with ashwagandha.
The second type, we call it “idiosyncratic reactions”. It is quite unpredictable, not dose-dependent; it takes quite a while to appear, and it depends on individual susceptibility. The ashwagandha cases clearly fall into this second category.
This is where we are going to get more technical, but if you bear with me, it’s quite interesting to understand what happens here.
Idiosyncratic reactions usually involve two steps.
In the first step, the substance is processed by liver enzymes, especially the cytochrome P450. Sorry about the technical term, but these are enzymes in the liver that do the detoxification. They are all coded with letters and numbers, and they all have an affinity for different substances based on their chemical configuration. So if the molecule looks like this, the liver will use enzyme A. If the molecule looks like that, it will use enzyme B to metabolize the substance, etc. Except that instead of being called A or B or C, they are called CYP3A4, CYP1A2, CYP2C8, etc. There is a whole bunch of them, because substances come in all kinds of flavors of chemical configuration. OK so far?
Well, we call this process “Phase I detox”. This will create reactive metabolites. Some of those are harmless; some are not. “Phase II” of the liver detox process is supposed to pick this up quickly and get rid of it for good. Once it comes out of Phase II, usually it is pretty harmless and ready to be evacuated in bile or urine.
But here is where it gets problematic. In some individuals, this Phase I to Phase II is not happening quickly enough; it is not efficient enough. So the metabolites getting stuck in between the two phases can do some damage. On top of that, if you add a high reactivity to those substances in a particular individual, then Houston, we have a problem.
This can lead to a buildup of toxic intermediates. Leading to inflammation, tissue damage, and eventually tissue death.
So which constituents of ashwagandha might be involved here? The main suspect is called withanone, which is one of the withanolides, which are identified as “active constituents”. You see, there are reactive chemical groups on that withanone molecule that can form what we call “DNA adducts”.
Think of your DNA as a long instruction manual for your cells, made of tiny building blocks. A DNA adduct happens when a foreign chemical sticks directly onto one of those building blocks. So it can disrupt normal cell function and increase the risk of diseases like cancer.
Again, if Phase II is not happening quickly enough, withanone will not be cleared fast enough, which increases the risk of toxicity.
OK, now that we understand the risk, let’s add one more complication. The issue may not be the root, which is the part of the plant traditionally used by herbalists. It may be the leaves. So what is going on here?
If you guessed that the leaves are cheaper to produce and to pick than the roots, you are correct, of course. Economics. The leaves are also higher in some constituents that we use to standardize the extracts. The leaves look even better on the product label, they make the product appear more concentrated.
So is there a risk of adulteration of ashwagandha powders and dried extract with the leaves? You bet there is. Unless you buy from a reputable source. Or unless you buy the entire roots (or cut in pieces), because it’s easy to make the difference between the roots and the leaves. With a fine powder, it is very easy to cheat.
And this is not theoretical. There are documented cases where the products are labeled as “root” but they actually contain significant amounts of leaf. This changes the chemical profile completely. Leaves contain much higher levels of withanolides, sometimes dramatically higher. Withanone included (Kaul 2016), remember, withanone is the constituent that may be implicated in the liver toxicity cases.
Interestingly, the detailed analysis in the Indian cases showed no major contaminants, no heavy metals, and no pollutants. So the issue is unlikely to be contamination with pollutants. It’s more likely intrinsic to the plant chemistry in certain sensitive individuals, possibly worsened by adding leaves in the root products.
But hold on. At this stage, you may ask, isn’t ashwagandha supposed to protect the liver? And the answer is… yes, that too!
Animal studies suggest an anti-inflammatory effect on the liver and a protective effect on liver cells (Alghamdi 2024). Yes, these are animal studies, and we should be careful about using them on humans. Still, it also points us in the other direction, a protective effect. If you are a bit confused, I understand, but plants can sometimes do that.
OK, at this stage, let’s conclude:
And there is also a possibility that this has been underreported because it takes time to appear and might be imputed to other causes.
Alright, now. Here are some practical implications for use in our practices. Here, I will share the recommendations provided by a great herbalist. His name is Simon Mills. I will link to the article he wrote on that specific topic. Simon Mills is just “the man”, quite respected in our circles, and the coauthor of an outstanding reference book called “The Principles and Practice of Phytotherapy”, written with Kerry Bone.
So here we go.
First point: control the source. Use roots only. Avoid products super high in withanolides. Work with trusted suppliers providing good traceability, or even better, work directly with the grower if they are also doing the transformation into powder or tincture for you, like in France. And you know what? You can also grind and sift the roots using a coffee grinder. At home.
Second point: if you take ashwagandha for yourself or you are recommending it to another person, make sure the person does not have liver issues. Cirrhosis, chronic liver disease, elevated liver markers (which is a sign of liver inflammation), and liver cancer.
Third point: make sure there isn’t any regular use of drugs that also strain the liver, like acetaminophen—also known as paracetamol, which is pretty harsh on the liver, so the liver is already taxed here.
If you integrate those 3 points in your reflection, there should be a very low probability that ashwagandha will be an issue. And the benefits, if recommended in the right context, will far outweigh the risks.
Before I let you go, I’d like to stress the fact that this issue goes way beyond ashwagandha. It highlights a broader challenge, which is the gap between traditional use and modern products
We now have concentrated extracts, which are powders where the plant is not recognizable anymore. Sure, it may kind of taste like ashwagandha root, but you may have other undesirable stuff in there. This is to be expected with globalized supply chains and an industry that is obsessed with optimizing profitability.
Ashwagandha is still a super valuable herb. Still widely considered safe. I will continue to recommend it to my clients in my private practice when I feel it is appropriate, but I will also be a little more careful and follow closely the recommendations provided by Simon Mills.
Here is a final question for you: are we seeing a problem with ashwagandha or a problem with how modern systems are reshaping traditional herbalism? Let me know what you think.
Thanks for being here. I will see you soon for the next episode of TheFrenchHerbal.
Björnsson HK, Björnsson ES, Avula B, Khan IA, Jonasson JG, Ghabril M, Hayashi PH, Navarro V. Ashwagandha-induced liver injury: A case series from Iceland and the US Drug-Induced Liver Injury Network. Liver Int. 2020 Apr;40(4):825-829. doi: 10.1111/liv.14393. Epub 2020 Feb 11. PMID: 31991029; PMCID: PMC8041491.
Inagaki K, Mori N, Honda Y, Takaki S, Tsuji K, Chayama K. A case of drug-induced liver injury with prolonged severe intrahepatic cholestasis induced by Ashwagandha. Kanzo. 2017;58:448–454.
Philips CA, Valsan A, Theruvath AH, Ravindran R, Oommen TT, Rajesh S, Bishnu S, Augustine P; Liver Research Club India. Ashwagandha-induced liver injury-A case series from India and literature review. Hepatol Commun. 2023 Sep 27;7(10):e0270. doi: 10.1097/HC9.0000000000000270. PMID: 37756041; PMCID: PMC10531359.
Alghamdi AAA, Abdallah EAA, El-Refaei MF. Anti-inflammatory and anti-angiogenic effects of Withania somnifera extract on liver toxicity induced by silver nanoparticles in vivo. J Med Life. 2024 Jul;17(7):728-738. doi: 10.25122/jml-2024-0050. PMID: 39440339; PMCID: PMC11493168.
Kaul, S., Ishida, Y., Tamura, K., Wada, T., Iitsuka, T., Garg, S., Kim, M., Gao, R., Nakai, S., Okamoto, Y., Terao, K., & Wadhwa, R. (2016). Novel Methods to Generate Active Ingredients-Enriched Ashwagandha Leaves and Extracts. PLoS ONE, 11. https://doi.org/10.1371/journal.pone.0166945.
