Bai Mao Gen (Woolly Grass Rhizome)

Chinese Herb Actions

Chinese Herb Dosage

• What is the typical dosage of Bai Mao Gen, and is fresh or dried used?

  Roughly 10–30 g in decoction, a notably wide and generous range compared with many other herbs, reflecting its gentle, food-like safety profile. Where available, the fresh rhizome is traditionally preferred and used at a larger dose than the dried form, as it is considered more effective for cooling Blood-heat and promoting urination; dried Bai Mao Gen is the more common substitute where fresh material is unavailable.

  Source: Sacred Lotus sources & references; standard materia medica dosage ranges. Reference only — not a prescription.

Chinese Herb Contraindications & Cautions

• Are there cautions for Bai Mao Gen?

  Use caution in Deficiency-Cold of the Spleen and Stomach — because Bai Mao Gen is cold in nature, it is not suited to a picture of Middle-Jiao (digestive) cold, and it should not be used for vomiting caused by cold in the Middle Jiao.

  Source: Sacred Lotus sources & references, cross-referenced against multiple online sources and materia medica consensus.

Chinese Herb Toxicity & Overdose

• Low. Bai Mao Gen has a long history of dietary use (the rhizome's sweet juice is traditionally chewed or drunk in parts of Asia) alongside its medicinal use, and materia medica sources do not report significant toxicity at standard doses; its main caution is a cold nature unsuited to Spleen/Stomach-cold presentations, not intrinsic toxicity.

  Source: materia medica consensus; cross-referenced against multiple online sources. Reference note, not a safety guarantee.

Western / Biomedical Research

Chinese Herb Clinical Studies & Research

Provided as research context — a summary of published biomedical study, not a therapeutic or medical claim.

• Is there modern research on Bai Mao Gen (Imperata cylindrica)?

  Yes — phytochemistry and preclinical pharmacology support several of its traditional actions, though controlled evidence for the diuretic claim specifically is mixed. A 2021 review catalogued roughly 72 constituents (saponins, flavonoids, phenols, and glycosides) and reported immunomodulatory, antibacterial, anti-inflammatory, antitumor, and hepatoprotective activity across in vitro and in vivo studies.

  • Antioxidant activity (in vitro) — an aqueous extract of Rhizoma Imperatae showed strong free-radical-scavenging and reducing power in laboratory assays, comparable to the ascorbic-acid (vitamin C) control, consistent with a high polyphenol content.
  • Diuretic effect (human, placebo-controlled) — a placebo-controlled, double-blind crossover study of four traditional Vietnamese diuretic herbs (including Imperata cylindrica, alongside Zea mays/corn silk, Plantago major, and Orthosiphon stamineus) found no measurable increase in urine output or sodium excretion under standardized testing conditions, despite the traditional reputation of these herbs as diuretics.

  Overall, laboratory evidence supports antioxidant and anti-inflammatory activity, but the one controlled human study identified did not confirm a diuretic effect, illustrating a real gap between traditional use and this specific clinical test.

  Note: The negative diuretic finding above comes from a small, older combination study (four herbs tested together under one protocol) and does not necessarily rule out an effect at different doses, preparations, or in the bleeding/heat-clearing contexts where Bai Mao Gen is traditionally used; it is presented here for balance, not as a refutation of traditional use.

  Sources: PMID 33800104 (Molecules, 2021, phytochemistry/pharmacology review of Imperata cylindrica); PMID 24146520 (African Journal of Traditional, Complementary and Alternative Medicines, 2013, antioxidant activity of Rhizoma Imperatae extract); PMID 1434681 (Journal of Ethnopharmacology, 1992, placebo-controlled diuretic study of four Vietnamese herbs including Imperata cylindrica). Research context, not a therapeutic claim.

Chinese Herb Notes

• Is Bai Mao Gen a gentle hemostatic herb?

  Yes — among the heat-clearing, blood-cooling hemostatics, Bai Mao Gen is considered one of the gentler choices, sweet and cold rather than bitter or harsh, and mild enough to double as a simple diuretic on its own for urinary difficulty.

  • Combines the cool-Blood and diuretic actions in one herb — useful specifically where bleeding (such as hematuria) and heat-type urinary discomfort occur together.
  • Food-grade safety profile — the wide dosage range and long dietary history (the rhizome is also chewed or made into a sweet drink in some regions) reflect its gentleness relative to stronger hemostatic or purgative herbs.

  Source: Sacred Lotus sources & references, cross-referenced against multiple online sources and materia medica consensus.