Polygonum Multiflorum: Uses, Side Effects, and Liver Risks

Polygonum multiflorum, known in traditional Chinese medicine as He Shou Wu and marketed in the West as fo-ti, is one of the most widely used herbal remedies in East Asia and one of the most consistently linked to liver damage. The plant’s root has been taken for centuries to darken graying hair, lower cholesterol, and slow aging, and modern lab research has identified compounds that lend some biological plausibility to those uses. But a growing body of clinical case reports and pharmacological studies has made this herb a textbook example of why “natural” does not mean safe, particularly for the liver.

What Polygonum Multiflorum Contains

Researchers have isolated more than 100 chemical compounds from the root of Polygonum multiflorum, with the major classes being stilbenes, quinones, and flavonoids.¹ The compound that gets the most attention is a stilbene glucoside abbreviated TSG (its full chemical name is unwieldy for anyone outside a chemistry lab).² TSG is often framed as the “good” ingredient, the one behind the plant’s antioxidant and lipid-lowering properties. The quinone compounds emodin and physcion, meanwhile, are pharmacologically active in their own right but also implicated in liver toxicity. The interplay between these classes of compounds, and how their concentrations shift depending on how the root is prepared, sits at the center of nearly every question about the herb’s safety and efficacy.

Traditional Uses and the Raw-Versus-Processed Distinction

In traditional Chinese medicine, raw and processed forms of the root are treated as fundamentally different medicines. The raw root is used mainly as a laxative and for detoxification. The processed form, which is typically steamed or stewed with black soybean juice, is the one prescribed for anti-aging purposes, hair darkening, and tonifying the liver and kidneys. This is not just folk wisdom layered on top of the same material. Chemical analysis shows that processing measurably alters the root’s composition: the content of TSG drops by roughly 56%, while emodin increases by about 34%.³ Other anthraquinone compounds disappear or decrease significantly during processing.⁴

The practical implication: animal toxicity testing shows that the raw form is considerably more toxic than the processed form.³ Processing appears to reduce the concentration of certain reactive compounds while changing the overall chemical profile. That said, processed Polygonum multiflorum is not safe by default. Both raw and processed forms have been reported to cause liver injury in clinical settings, and deaths have occurred with both.⁵ The reduction in toxicity from processing is real but not a guarantee of safety, a distinction that matters because many supplement labels do not specify which form is being sold.

Hair Growth Claims

The most popular reason people seek out Polygonum multiflorum today is probably hair. The traditional claim is that it can reverse graying and prevent hair loss, and there is some laboratory evidence pointing in an interesting direction, though none of it involves humans taking it orally and measuring new hair growth.

In cell culture and animal experiments, extracts of Polygonum multiflorum have shown the ability to push hair follicles into an active growth phase. One study using cultured human hair follicle cells found that the extract increased cell viability, boosted the production of several growth factors, and counteracted some of the effects of dihydrotestosterone, the androgen most associated with pattern baldness. In an organ culture model using actual human hair follicles, the extract prolonged the growth phase and delayed the regression phase.⁶ A separate mouse study found that topical application of the extract promoted hair regrowth from resting follicles.⁷ Specific compounds isolated from the root were also tested on hair follicle cells, with one compound outperforming the standard hair-loss drug minoxidil at promoting cell proliferation and increasing hair fiber length in an isolated follicle model.⁸

These results are genuinely intriguing, but they come with a critical limitation: cells in a dish and mice are not people taking an oral supplement. There is no published, well-controlled clinical trial in humans demonstrating that ingesting Polygonum multiflorum products produces meaningful hair regrowth or reversal of graying. The gap between “promising in vitro and animal data” and “proven to work in humans” is enormous in pharmacology, and this herb has not crossed it. If you are considering it for hair loss, this is what the evidence actually supports: biologically plausible, not clinically proven.

Cholesterol and Lipid Effects

The lipid-lowering properties of Polygonum multiflorum have somewhat stronger mechanistic detail, though the evidence remains preclinical. In animal models of high cholesterol, oral administration of raw root extract significantly reduced LDL cholesterol, total cholesterol, and triglycerides. One study found that at high doses, the extract relieved fatty changes in liver cells and outperformed simvastatin, a common pharmaceutical cholesterol drug, in the animal model tested.⁹ Another study in animals found that low-dose preparations effectively reduced blood triglycerides, total cholesterol, and LDL levels.¹⁰

The mechanisms appear to involve multiple active compounds working through different pathways. TSG seems to promote the breakdown of cholesterol and reduce LDL. Emodin inhibits a key enzyme involved in cholesterol synthesis, which is essentially the same mechanism statin drugs use. Physcion boosts the breakdown of triglycerides.¹¹ The lipid-lowering effect appears to come from the synergy of all three compounds rather than any single ingredient. This is the kind of finding that would normally generate interest in drug development, but the herb’s liver toxicity profile creates an obvious problem: a cholesterol-lowering agent that also sometimes destroys the organ responsible for cholesterol metabolism is not a viable treatment without much better ways to predict who will be harmed.

How Liver Damage Happens

The liver toxicity of Polygonum multiflorum has been documented extensively enough that researchers have given it its own acronym: PM-DILI (Polygonum multiflorum drug-induced liver injury). A systematic review of published case reports found that out of 450 patients with liver damage associated with the herb, seven died and two required liver transplants. The remaining patients recovered or improved after stopping the product and receiving supportive care.¹² The most common type of injury was direct damage to liver cells, accounting for about 60% of cases, with the rest split between bile-flow obstruction and mixed patterns.¹²

Symptoms typically appear about a month after someone starts taking the product, and the most common warning sign is jaundice, the yellowing of the skin and eyes. In a clinical study of 29 patients with confirmed He Shou Wu liver injury, roughly 80% presented with jaundice. The median age was 53, and about three-quarters of those affected were women. Most patients saw their liver enzymes return to normal within about 45 days of stopping the herb.¹³ But one patient in that group died of liver failure, and three developed chronic persistent liver injury. One patient who was rechallenged with the herb, meaning they took it again after recovering, developed liver problems a second time.

The underlying mechanisms are multiple and still being untangled. Research points to several pathways including disruption of cellular energy production, interference with bile acid excretion, alteration of metabolic pathways, immune system activation, and genetic factors.¹⁴ Paradoxically, some of the same compounds responsible for the herb’s beneficial effects, including emodin and possibly TSG, also contribute to its toxicity.¹⁵ This paradox, beneficial compounds doubling as toxic ones, is part of what makes the herb so difficult to regulate and dose safely.

Why Some People Are Vulnerable and Others Are Not

One of the most puzzling aspects of Polygonum multiflorum liver toxicity is that it does not affect everyone. Many people take it without apparent harm, while others develop severe liver injury. This pattern strongly suggests an idiosyncratic reaction, meaning it depends on individual biology rather than a straightforward dose-response relationship.

The most significant breakthrough in understanding this vulnerability came from a study that identified a specific genetic variant, HLA-B*35:01, as a powerful risk factor. In a pilot study, this gene variant was present in about 45% of patients with Polygonum multiflorum liver injury compared to under 3% of the general Han Chinese population. Combined analyses put the odds ratio at staggering levels: people carrying HLA-B*35:01 were roughly 144 times more likely to develop liver injury from the herb than population controls. In a prospective follow-up, carriers of this variant who took the herb had about an eightfold higher incidence of elevated liver enzymes compared to non-carriers.¹⁶

Follow-up computational and experimental work has begun to explain why this particular gene variant creates vulnerability. The HLA-B*35:01 protein has a binding pocket that can grab onto modified fragments of emodin-glucoside, one of the herb’s anthraquinone compounds. In theory, this binding triggers an immune response against the person’s own liver cells, essentially causing the immune system to mistake chemically altered liver tissue for a foreign invader.¹⁷ This is consistent with the clinical observation that some patients develop autoimmune features during their liver injury.¹³

This genetic link is clinically important because it means the risk is not random. In principle, a genetic test before use could identify the most vulnerable individuals. No such screening protocol is standard practice yet, and the variant is common enough in East Asian populations that a significant minority of potential users carry it. Given that the herb is overwhelmingly sold as an unregulated supplement without genetic screening, the practical reality is that many high-risk individuals take it unknowingly.

Estrogenic Activity

A less discussed but potentially significant finding is that Polygonum multiflorum (sold in the West as fo-ti) has surprisingly high estrogenic activity. Laboratory testing using a recombinant cell assay found estrogen activity levels that had not been previously reported, measuring at about 1/300th the potency of the body’s own estradiol.¹⁸ While 1/300th sounds low, the concentrations achievable through regular supplementation could plausibly produce hormonal effects, particularly in people with estrogen-sensitive conditions such as certain breast cancers, uterine fibroids, or endometriosis. This is rarely mentioned on supplement labels and represents an additional dimension of risk beyond the liver.

Regulatory Warnings and the Supplement Gap

The liver risks have prompted regulatory action in several countries. The UK’s Medicines and Healthcare products Regulatory Agency issued a warning about potential risks with Polygonum multiflorum.¹⁹ Regulatory agencies in several other countries, including Australia and Canada, have also flagged or restricted the herb. China’s own drug regulatory authority has reclassified preparations containing it and added safety labeling requirements.

In the United States, however, Polygonum multiflorum products remain widely available as dietary supplements, which are not subject to premarket safety testing. You can buy He Shou Wu or fo-ti capsules at most health food stores and online retailers with no warning labels about liver toxicity. This regulatory gap is the core practical problem. The herb is treated as a food supplement in the largest supplement market in the world, while the evidence clearly shows it can cause serious, occasionally fatal, organ damage in a subset of users who have no way to know in advance whether they are susceptible.

The Disclosure Problem

Even when people do take herbal products, they frequently do not tell their doctors about it. A multicenter study of patients with chronic diseases found that the most common reason for not disclosing herbal medicine use was the belief that “herbal medicine is safe because it is natural,” cited by about 53% of non-disclosers. Nearly half also believed there were no interactions with their conventional medications.²⁰ About a third said their healthcare provider never asked, and roughly 15% feared disapproval.

This matters for Polygonum multiflorum specifically because if someone develops jaundice or elevated liver enzymes while secretly taking the herb, the cause may be missed or attributed to something else entirely. Delayed diagnosis means continued exposure, and continued exposure means worse outcomes. If you take any form of He Shou Wu, fo-ti, or any supplement listing Polygonum multiflorum as an ingredient, mentioning this to your doctor is not optional, especially if you have any existing liver condition or take medications metabolized by the liver.

What the Quality Control Landscape Looks Like

Beyond the inherent toxicity of the plant’s compounds, product quality adds another layer of unpredictability. Because Polygonum multiflorum supplements are largely unregulated in Western markets, the consumer faces several unknowns: whether the root was raw or processed, the concentration of active and toxic compounds, whether the preparation was adulterated with other botanicals or contaminants, and the actual dose being delivered per capsule or serving. The hepatotoxicity literature makes clear that the reasons for liver injury are “multioriginal,” meaning that contamination, incorrect processing, improper storage, and individual susceptibility all contribute to the overall risk.⁵ A person might react badly to a product not because Polygonum multiflorum is inherently deadly at any dose but because the particular product they purchased delivered an unpredictable chemical payload.

In the clinical study of 29 liver injury patients, outcomes were comparable whether patients had taken pure He Shou Wu or compound formulas containing it alongside other herbs.¹³ This suggests that blending it with other ingredients does not dilute the risk in any reliable way. The herb is the problem, not the formulation surrounding it.

Who Should Avoid It Entirely

Given the current evidence, several groups face particularly high risk and should steer clear of Polygonum multiflorum products altogether:

People with existing liver disease: Any baseline liver impairment reduces the organ’s ability to handle a hepatotoxic insult.
People taking hepatotoxic medications: Combining the herb with drugs known to stress the liver, including acetaminophen at high doses, certain antibiotics, and some cholesterol medications, could compound the danger.
People with estrogen-sensitive conditions: The herb’s estrogenic activity could worsen hormone-driven cancers, fibroids, or endometriosis.
Pregnant or breastfeeding women: The estrogenic effects and liver risks together create an unacceptable profile for this population.
People of East Asian descent: The HLA-B*35:01 risk variant is most prevalent in East Asian populations, meaning the people most culturally likely to use He Shou Wu are also the most genetically vulnerable to its liver effects.

For anyone else considering the herb, the honest risk-benefit calculation is unfavorable. The uses it is taken for, hair growth, anti-aging, cholesterol reduction, either lack human clinical trial evidence or have well-established pharmaceutical alternatives that do not carry the risk of acute liver failure. If you still choose to use it, periodic liver function testing through simple blood work is the minimum precaution, and stopping immediately at the first sign of jaundice, dark urine, persistent fatigue, or abdominal pain is essential.

Topical Use as an Alternative Route

One area that may eventually offer a way around the liver problem is topical application. The mouse study that found hair regrowth from Polygonum multiflorum applied it directly to the skin rather than giving it orally.⁷ Topical delivery could, in principle, provide the hair follicle-stimulating effects while bypassing first-pass liver metabolism, dramatically reducing the hepatotoxicity concern. This approach mirrors how minoxidil works: applied to the scalp, absorbed locally, with minimal systemic exposure. No commercial Polygonum multiflorum topical product has undergone rigorous clinical testing for hair loss in humans, but the logic of the route is sound and represents the most plausible path toward a useful product with an acceptable safety profile. For now, though, this remains a laboratory curiosity rather than an evidence-based recommendation.