Polygonum Herb Extract
Also known as: He-Shou-Wu, Fo-ti, Polygonum Herb Extract, Polygonum multiflorum Thunb., Polygonum multiflorum
Overview
Polygonum multiflorum, commonly known as He-Shou-Wu or Fo-ti, is a perennial plant widely used in Traditional Chinese Medicine (TCM). It is primarily valued for its purported anti-aging properties, benefits for hair health (including darkening), and liver support. The extract contains various bioactive compounds, notably stilbenes (like resveratrol derivatives), quinones (such as emodin and rhein), and flavonoids. While traditionally used for improving insomnia and coordination, and sometimes for liver health, the scientific evidence supporting these claims is moderate. Much of the existing research consists of in vitro and animal studies, with limited and often low-quality clinical trials. A significant concern associated with Polygonum multiflorum is its potential for hepatotoxicity, making it a leading cause of herb-induced liver injury (HILI) in some regions.
Benefits
While Polygonum multiflorum has traditional uses, robust clinical evidence for its benefits is limited and often overshadowed by safety concerns. Some research suggests potential hepatoprotective and anti-aging effects, primarily attributed to its stilbene compounds, which possess antioxidant and anti-inflammatory properties. However, these findings are largely from preclinical studies, and high-quality randomized controlled trials (RCTs) confirming clinical benefits are lacking. Traditionally, it has been used for hair pigmentation and to alleviate neurological symptoms like dizziness and insomnia, but strong clinical data to support these uses are also absent. Any reported benefits, often anecdotal or from small studies, typically manifest after weeks to months of consistent use. Middle-aged adults are a population that traditionally uses this herb for hair and liver-related issues, but the strength of evidence for these benefits remains low.
How it works
The mechanism of action of Polygonum multiflorum is complex, involving multiple bioactive compounds. Stilbenes, such as resveratrol derivatives, are believed to contribute to its potential hepatoprotective effects through their antioxidant and anti-inflammatory properties. Quinones, including emodin and rhein, are also present and may play a dual role, contributing to both therapeutic effects and, notably, hepatotoxicity. The herb's interaction with the body's systems is not fully understood, but potential immunologically mediated liver injury has been proposed as a mechanism for its adverse effects. Furthermore, Polygonum multiflorum may interact with cytochrome P450 enzymes and P-glycoprotein, suggesting a potential for herb-drug interactions.
Side effects
The safety profile of Polygonum multiflorum is a significant concern due to its well-documented potential for hepatotoxicity. It is recognized as a leading cause of herb-induced liver injury (HILI), particularly in China. Common side effects, affecting more than 5% of users, include symptoms of liver injury such as jaundice, fatigue, anorexia, and choluria (dark urine). Less common side effects (1-5%) can involve hepatomegaly (enlarged liver) and patterns of cholestatic or hepatocellular liver damage. In rare cases (less than 1%), severe liver failure has been reported. Potential drug interactions exist due to its modulation of CYP450 enzymes and P-glycoprotein. Contraindications include individuals with pre-existing liver disease, those concurrently taking other hepatotoxic drugs, and caution is advised for middle-aged men who appear to be more susceptible to adverse effects. Due to a lack of safety data, Polygonum multiflorum is not recommended for use during pregnancy or breastfeeding.
Dosage
There is no standardized or universally established safe dosage for Polygonum multiflorum due to significant safety concerns, particularly regarding hepatotoxicity. Reported clinical dosages vary widely, ranging from 3 grams per day to 20 grams per day, but these are not based on high-quality, safety-validated clinical trials. It is important to note that alcohol extracts of Polygonum multiflorum appear to be more hepatotoxic than traditional water extracts or decoctions. A clear minimum effective dose has not been established through rigorous clinical research. Liver injury symptoms typically manifest within 1 to 2 months of starting supplementation. Given the substantial risks, any use should be approached with extreme caution and under strict medical supervision, if at all.
FAQs
Is Polygonum multiflorum safe?
No, Polygonum multiflorum carries a significant risk of liver injury (hepatotoxicity). It should be used with extreme caution and only under strict medical supervision, if at all.
How soon do side effects appear?
Liver injury symptoms typically appear within 1 to 2 months of starting supplementation with Polygonum multiflorum.
Can liver injury be reversed?
In many cases, liver injury resolves after discontinuing the herb. However, severe cases may require significant medical intervention.
Are benefits proven?
Clinical benefits of Polygonum multiflorum are not conclusively demonstrated in high-quality, rigorous clinical trials. Evidence is mostly from traditional use or preclinical studies.
Research Sources
- https://www.nature.com/articles/aps2016147 – This computational systems toxicology study, combined with animal data, investigated the dual effects of Polygonum multiflorum compounds. It identified that stilbenes may offer hepatoprotective effects, while quinones are associated with hepatotoxicity, providing mechanistic insights into the herb's complex actions.
- https://www.wjgnet.com/2307-8960/full/v9/i20/5490.htm – This systematic review of herb-induced liver injury (HILI) cases highlights Polygonum multiflorum as a leading cause of HILI in China. It notes that symptoms often reverse upon withdrawal of the herb and suggests an immunological mechanism for the liver damage, emphasizing the significant safety concerns.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC4471648/ – This narrative review discusses the herb-drug interactions and pharmacokinetics of Polygonum multiflorum. It underscores the complexity arising from its multiple bioactive compounds and points out the lack of large-scale randomized controlled trials to fully understand its effects and interactions.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC6923272/ – This review specifically focuses on the mechanisms of hepatotoxicity associated with Polygonum multiflorum. It suggests that alcohol extracts are more hepatotoxic than water extracts and indicates that modern extraction methods might inadvertently increase the concentration of toxic components, impacting safety.
- https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2025.1573034/full – This meta-analysis examined the effects of natural extracts on cognition, including some Polygonum species. While it included Polygonum odoratum as potentially beneficial for cognition, it noted limited direct data specifically on Polygonum multiflorum, indicating that evidence for cognitive benefits from this particular species is indirect or scarce.
