Polygonum
Also known as: He-Shou-Wu, Fo-ti, Shou-Wu-Pian, Polygonum multiflorum
Overview
Polygonum multiflorum (PmT) is a perennial plant native to China, widely used in Traditional Chinese Medicine (TCM) for its purported anti-aging, hair growth, and liver health benefits. It is commonly used as a hair tonic, to improve insomnia, and for neurological coordination. The herb contains various chemical constituents, including stilbenes (e.g., resveratrol-like compounds), quinones (e.g., emodin, rhein), and flavonoids. While there is a moderate amount of preclinical studies and clinical case reports, high-quality randomized controlled trials (RCTs) are limited. The evidence quality is primarily based on anecdotal reports, animal studies, and computational analyses, with significant safety concerns, particularly regarding hepatotoxicity, dominating the literature. It is often classified as a botanical or phytochemical supplement.
Benefits
Traditionally, Polygonum multiflorum is claimed to improve hair pigmentation and growth, offer anti-aging effects, and enhance sleep and neurological coordination. Some animal studies suggest hepatoprotective effects at specific doses, but these findings are often contradicted by evidence of liver toxicity at other doses. However, there is a significant lack of large-scale, high-quality randomized controlled trials (RCTs) to confirm these clinical benefits. Most reported benefits are anecdotal or derived from small-scale studies, making it difficult to quantify efficacy or establish clear effect sizes. The strength of evidence for its benefits is generally considered low, with safety concerns often outweighing potential advantages.
How it works
Polygonum multiflorum contains bioactive compounds such as stilbenes and quinones (like emodin and rhein). Stilbenes are thought to possess anti-oxidative and anti-aging properties. Quinones, however, exhibit dual effects: they may be hepatoprotective at low to moderate doses, possibly through antioxidant and anti-inflammatory pathways, but become hepatotoxic at higher doses or with prolonged use, likely via an immunologically mediated liver injury. The herb's extracts can inhibit cytochrome P450 enzymes (CYP2E1, CYP1A2), which may affect drug metabolism. The mechanism of hepatotoxicity is believed to involve immune-mediated inflammatory cell infiltration and direct hepatocellular damage. The bioavailability and pharmacokinetics in humans are not yet fully characterized.
Side effects
Polygonum multiflorum carries significant safety concerns due to its well-documented hepatotoxicity, making it a leading cause of herb-induced liver injury (HILI) in China. Common side effects include jaundice, fatigue, anorexia, choluria, hepatomegaly, and elevated liver enzymes. Severe liver failure requiring hospitalization is a rare but serious risk. Liver injury typically manifests about one month after starting supplementation, and withdrawal of the herb usually leads to symptom resolution within approximately 30 days. Corticosteroids are not recommended for treatment of HILI from PmT. Potential drug interactions exist, particularly with CYP3A4 substrates, due to enzyme inhibition. Contraindications include pre-existing liver disease, and middle-aged men appear to be more susceptible to adverse effects. There is no safety data for pregnant women or children, thus caution is strongly advised for these populations.
Dosage
Clinical dosing of Polygonum multiflorum varies widely, with reported cases ranging from 3 g/day to 20 g/day. However, toxicity has been reported even at doses considered clinically equivalent. Due to a lack of rigorous efficacy data, there is no established minimum effective dose. Long-term use, defined as more than one month, significantly increases the risk of liver injury. Different preparations, such as raw versus processed forms, may vary in their toxicity, with processed forms potentially having reduced hepatotoxicity, though they still carry risk. There is no consensus on optimal dosing or duration of use, and caution is strongly advised given the significant safety concerns. Upper limits and safety thresholds are not well-defined due to the inherent risks.
FAQs
Is Polygonum multiflorum safe?
No, there is a well-documented and significant risk of liver injury (hepatotoxicity), especially with prolonged use or high doses. It is a leading cause of herb-induced liver injury in China.
Can it improve hair growth?
Traditional use suggests it can, but high-quality clinical evidence to support this claim is lacking. Most benefits are anecdotal or from small-scale studies.
How soon do side effects appear?
Liver injury typically manifests within approximately one month of starting supplementation, though onset can vary.
What should I do if liver injury occurs?
Discontinue use immediately. Liver function usually normalizes within about a month after cessation. Medical consultation is advised.
Are processed forms safer?
Processed forms may have reduced hepatotoxicity compared to raw forms, but they are not risk-free and still carry the potential for liver injury.
Research Sources
- https://pmc.ncbi.nlm.nih.gov/articles/PMC8281430/ – This systematic review and meta-analysis identified Polygonum multiflorum as the most prevalent herb causing herb-induced liver injury (HILI) in China. It found that liver injury typically occurs around 58 days after starting use, with most cases recovering upon withdrawal of the herb. The study suggests the injury pattern is primarily hepatocellular and likely immune-mediated, noting no proven effective treatment beyond cessation.
- https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2019.01467/full – This systematic review focused on Polygonum multiflorum-induced liver injury, highlighting that animal studies demonstrated dose- and time-dependent liver damage from both raw and processed forms. It noted that continuous administration at doses equivalent to or exceeding clinical doses led to inflammatory liver changes and observed CYP enzyme inhibition, suggesting potential drug interactions and metabolic disruption.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC4471648/ – This review of clinical studies analyzed 54 publications, including 52 patients with hepatotoxicity from Polygonum multiflorum. It found mixed and inconclusive evidence for therapeutic effects, but consistent reports of liver injury. The review concluded that safety concerns, particularly liver toxicity, dominate the clinical literature regarding this herb.
- https://www.nature.com/articles/aps2016147 – This computational systems toxicology study identified over 100 chemical components in Polygonum multiflorum with biphasic effects on liver cells. It suggested that stilbenes might offer hepatoprotective effects, while quinones like emodin and rhein contribute to hepatotoxicity. The study highlighted that these dual effects complicate the clinical use and risk assessment of the herb.
- https://www.webmd.com/vitamins/ai/ingredientmono-768/fo-ti – This source provides general information on Fo-ti (Polygonum multiflorum), including its traditional uses and common names. It also touches upon the safety concerns associated with its use, particularly liver damage, and advises caution.
