Fo-ti (He shou wu): the traditional tonic with a real hepatotoxicity signal

Fo-ti — the dried root of Polygonum multiflorum, sold under names like He shou wu, fleeceflower, or shou wu pian — has a documented and reproducible hepatotoxicity signal across hundreds of reported cases and regulatory action from multiple national agencies. The hair-darkening and longevity claims that drive the supplement market are essentially unsupported by controlled human data, while the liver harm signal is one of the better characterized in herbal hepatotoxicity.

What the herb actually is

Polygonum multiflorum root has been used in traditional Chinese medicine for centuries. Two preparations exist: raw root (sheng he shou wu) and processed root (zhi he shou wu) prepared by stewing with black bean broth. The processing reduces anthraquinone glycoside content. Both preparations contain stilbene glycosides (2,3,5,4'-tetrahydroxystilbene-2-O-beta-D-glucoside, abbreviated TSG), emodin and other anthraquinones, and tannins.

The hepatotoxicity case series

By 2014, the Chinese National Adverse Drug Reaction Monitoring Center had collected more than 450 case reports of fo-ti-associated liver injury [1]. A subsequent systematic review of 76 published cases meeting causality criteria reported a hepatocellular injury pattern with median onset 4–8 weeks after starting, transaminases typically 10–30× upper limit of normal, and complete recovery in most cases after discontinuation but occasional fatalities [2]. The UK MHRA, Australian TGA, and Japanese PMDA have issued formal warnings.

Mechanism and idiosyncrasy

Hepatotoxicity is idiosyncratic — it does not happen in everyone — but a genetic susceptibility through HLA-B*35:01 has been identified, with carriers at substantially elevated risk [3]. Mechanistic work points to mitochondrial dysfunction induced by anthraquinones and possibly TSG. Raw root carries higher anthraquinone load and a higher case rate; processed root reduces but does not eliminate the signal.

What the efficacy data show

Despite extensive traditional use for hair color, longevity, and 'kidney essence,' randomized controlled human evidence for any of these indications is essentially absent. A handful of small Chinese trials report subjective improvements, but methodology is generally poor. The TSG fraction has been investigated as a candidate for Alzheimer's and Parkinson's in animal models without translation.

Drug interactions

Fo-ti is a moderate CYP3A4 inhibitor in vitro and a confirmed precipitant of warfarin-associated INR fluctuations in case reports. Concurrent use with hepatically cleared drugs — statins, calcineurin inhibitors, many antibiotics — increases the risk window for hepatotoxicity even at lower exposures. Concurrent acetaminophen at doses near the toxic threshold is particularly risky.

Regulatory status

The UK MHRA banned fo-ti-containing products in 2006 after a cluster of liver injury reports. The Australian TGA and Japanese health authorities require warnings on labeling. In the US it remains legal as a dietary supplement, with no warning labeling requirements outside of voluntary GMP standards. The FDA has issued occasional adverse event letters but not a formal action.

The bottom line

Fo-ti / He shou wu has a documented, regulator-recognized hepatotoxicity risk and no high-quality controlled human evidence of efficacy for any of its marketed uses. The use case is hard to justify outside of a traditional medicine context with experienced practitioner supervision. Anyone using it should at minimum check baseline liver function and repeat at 4–8 weeks; concurrent hepatically active drugs are a contraindication.