Yu Mi Xu (Cornsilk)

Chinese Herb Actions

Chinese Herb Dosage

• What is the typical dosage of corn silk?

  15–30 g in decoction, rising to 45–60 g in severe cases — among the largest routine doses in the materia medica. Both recorded reference ranges start at 15–30 g and agree; only one of them extends to the higher figure for severe presentations. The reason the numbers run so high is partly that the material is extremely light and fluffy, and partly that it is very mild.

  • Decoction — 15–30 g, per both recorded ranges; up to 45–60 g in severe cases per one of them.
  • Part used — the styles and stigmas (the “silk”) from the female flower of maize, gathered when the ear is picked and dried.
  • As a tea — the common Western form is a simple infusion or decoction of the dried silk, which is essentially the same preparation.
  • Fresh versus dried — dried material is standard; fresh silk is used in some regional practice at correspondingly higher weights, since most of the fresh weight is water.

  Source: Sacred Lotus sources & references (both recorded reference ranges, as held on file); cross-referenced against multiple online sources and materia medica consensus. Reference only — not a prescription.

Chinese Herb Contraindications & Cautions

• Are there cautions for corn silk? Is it safe?

  No traditional contraindication is recorded for corn silk on this site — the entry reads “none noted” — and it is about as benign a herb as the materia medica contains. The sensible cautions are all about what it does rather than what it contains.

  • It is a diuretic. The most predictable caution for any herb that increases urine output: fluid and electrolyte balance, particularly in anyone already taking a diuretic medicine or with impaired kidney function. See the interactions note.
  • Yin deficiency or dehydration — the general caution for the damp-draining category. Draining fluids from someone already dry is counterproductive.
  • Pregnancy — no traditional prohibition is recorded. One reference point, reported neutrally: a 2025 developmental toxicity study in pregnant rats found no maternal or foetal toxicity, no genotoxicity and no malformations from a standardised corn silk extract, but did observe increased pre-implantation losses at the highest dose tested (1200 mg/kg). The authors’ own conclusion was that this dose may interfere with early pregnancy in that species. Animal data at a dose far above ordinary human use; professional guidance is the appropriate route in pregnancy.
  • Blood glucose and blood pressure — human studies have measured reductions in both (see research). Anyone being treated for diabetes or hypertension should keep their prescriber informed rather than layering effects unmonitored.
  • Corn allergy — obvious but worth stating for a herb harvested from a staple food crop.

  Source: Sacred Lotus sources & references (recorded cautions entry, “none noted”); gestational toxicity data per PMID 40984809, DOI 10.1002/bdr2.2526; category cautions per materia medica consensus, cross-referenced against multiple online sources. Reference note, not a safety guarantee.

Chinese Herb Toxicity & Overdose

• Is corn silk toxic?

  No. The entry held here reads “none noted,” corn silk is not classed among the toxic materia medica, and the animal safety data that exist are reassuring at ordinary exposures. It is a food by-product with a long history as a household tea.

  • Acute toxicity — an aqueous extract given by gavage to rats at doses up to 5 g/kg body weight caused no mortality and was reported as non-toxic at that level.
  • Repeated dosing — in the same study, 28 days of 500, 1000 or 2000 mg/kg produced changes in lipid and liver measures at the higher doses, and degenerative changes in the liver at 2000 mg/kg. Reported honestly: this is a very high multiple of any culinary or medicinal exposure, but it is the reason “food-grade” should not be read as “unlimited.”
  • Pregnancy — see the cautions note; a 2025 gestational study found no maternal or foetal toxicity and no malformations, with an effect on pre-implantation loss only at the top dose.
  • The usual caveat — no formal clinical safety evaluation of corn silk exists in the literature that could be confirmed. Absence of reported harm is not the same thing.

  Source: Sacred Lotus sources & references (recorded toxicity entry, “none noted”); acute and 28-day oral toxicity per PMID 30558395, DOI 10.17306/J.AFS.0601; gestational assessment per PMID 40984809, DOI 10.1002/bdr2.2526. Neutral reference facts — not a safety guarantee.

Herb-Drug Interactions

• Does corn silk interact with medications?

  No clinical herb–drug interaction has been formally documented, but three sensible cautions follow from measured effects rather than from speculation: diuretics, blood-pressure medicines and glucose-lowering medicines. This record already flags the first of these.

  • Prescription diuretics — the recorded caution on this site, and a reasonable one. Corn silk’s diuretic action has been demonstrated in rats, and a study in conscious rats found that maize extracts altered glomerular function and increased urinary potassium excretion. Adding a herbal diuretic to a prescribed one without supervision is the classic way to run into trouble with fluid and potassium balance. No adverse interaction has actually been documented; this is precaution, not a demonstrated event.
  • Antihypertensives — in a randomised human study, aqueous corn silk extract produced dose-dependent, statistically significant reductions in blood pressure (and in intraocular pressure) within eight hours in both hypertensive and non-hypertensive subjects. The authors attributed the effect to potassium-induced natriuresis and diuresis. An additive effect with blood-pressure medication is therefore plausible.
  • Glucose-lowering medicines — randomised human work reports reductions in fasting glucose and glycated haemoglobin after three months of corn silk in newly diagnosed type 2 diabetes, and reductions in postprandial glucose from corn silk extract combinations in prediabetic and diabetic adults. Layering this on top of prescribed treatment without monitoring is the concern.

  Unverified claim flagged: the interaction entry previously held here also stated that corn silk contains vitamin K and should therefore be used cautiously with warfarin. That claim could not be substantiated — no analysis reporting vitamin K (phylloquinone) content in corn silk could be found in the sources checked, and the constituent reviews of the herb do not list it. It is reported here as unverified rather than repeated as fact. Anyone taking an anticoagulant should in any case tell their prescriber about all herbal products.

  Sources: Sacred Lotus sources & references (recorded interaction entry); PMID 15638089 (diuretic activity of maize stigma extract in rats); PMID 15957371, DOI 10.1016/j.phymed.2003.12.010 (glomerular function and urinary potassium excretion in conscious rats); PMID 25727941, DOI 10.1111/cxo.12240 (randomised human study, blood pressure and intraocular pressure); PMID 39151489, PMC 11332781, DOI 10.1097/MD.0000000000039396 (randomised trial, glycaemic measures in type 2 diabetes); PMID 41228506, PMC 12610157, DOI 10.3390/nu17213438 and PMID 40187731, DOI 10.1016/j.clnesp.2025.03.174 (randomised crossover trials, postprandial glucose). Reference context only — not medical advice. Flagged for practitioner confirmation.

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 corn silk (Zea mays stigmas)?

  Yes — and unusually for a minor herb, some of it is in humans. Corn silk has randomised trial data for blood glucose and blood pressure, a meta-analysis of Chinese trials for blood lipids, and a substantial preclinical literature confirming the diuretic action that its traditional indication rests on. Being a cheap, abundant food by-product, it attracts more research attention than its status in the materia medica would suggest.

  • Diuresis — the traditional action — a rat study demonstrated diuretic activity of maize stigma extract, and a study in conscious rats found that Zea mays extracts modified glomerular function and increased urinary potassium excretion. This is the closest laboratory correspondence to “promotes urination and reduces oedema,” and it is animal work.
  • Blood glucose (human) — a randomised, placebo-controlled study in newly diagnosed type 2 diabetes reported significantly reduced fasting glucose and glycated haemoglobin after three months of corn silk, with untargeted metabolomics pointing to oxidative phosphorylation and purine metabolism among the affected pathways. Two further randomised crossover trials, in prediabetic and in type 2 diabetic adults, tested corn silk extract combined with mulberry leaf and reported reduced postprandial glucose. Small trials of extracts and combinations, not of the decocted herb.
  • Blood pressure and intraocular pressure (human) — a randomised study of masked doses of aqueous corn silk extract in 40 subjects found dose-dependent, statistically significant reductions in both blood pressure and intraocular pressure within eight hours, peaking at three and four hours respectively. The authors attributed the effect to the extract’s high potassium content.
  • Blood lipids (meta-analysis) — a 2019 systematic review pooled four randomised trials of corn silk decoction in patients with angina pectoris and found improvements in total cholesterol, triglycerides, LDL and HDL. The authors state plainly that most of the included studies were unblinded and that the effects may therefore be overestimated — a caveat that belongs with the result.
  • Constituents — flavonoids (maysin is the characteristic one), phenolic acids, terpenoids, polysaccharides, potassium and vitamin-like compounds. Three reviews between 2012 and 2025 cover the phytochemistry and the reported antioxidant, anti-inflammatory, antihyperglycaemic, antihypertensive and diuretic activities, with the most recent framing the herb around age-related disease.
  • Metabolic syndrome — a dedicated review summarises the preclinical case for corn silk in the metabolic syndrome cluster (glucose, lipids, blood pressure, weight), which is the modern research theme that most nearly overlaps the herb’s traditional damp-heat indications.

  Honest summary: the human evidence is real but thin — small trials, extracts rather than the herb as traditionally decocted, and mostly unblinded in the case of the lipid data. It supports taking corn silk seriously as a mild functional food; it does not establish clinical efficacy for anything, and nothing here is a treatment claim.

  Sources: PMID 22890173, PMC 6268265, DOI 10.3390/molecules17089697 (phytochemical and pharmacological review); PMID 38398644, PMC 10891732, DOI 10.3390/molecules29040891 (narrative review of phytochemistry and biological activities); PMID 40437199, DOI 10.1002/mnfr.70117 (bioactive compounds and age-related disease); PMID 28950827, DOI 10.2174/1381612823666170926152425 (corn silk and metabolic syndrome); PMID 15638089 (diuretic activity in rats); PMID 15957371, DOI 10.1016/j.phymed.2003.12.010 (glomerular function and potassium excretion in conscious rats); PMID 15665587, DOI 10.1038/emm.2004.69 (nitric oxide synthase induction in murine macrophages); PMID 39151489, PMC 11332781, DOI 10.1097/MD.0000000000039396 (randomised trial with metabolomic profiling in type 2 diabetes); PMID 41228506, PMC 12610157, DOI 10.3390/nu17213438 and PMID 40187731, DOI 10.1016/j.clnesp.2025.03.174 (randomised crossover trials, postprandial glucose); PMID 25727941, DOI 10.1111/cxo.12240 (blood pressure and intraocular pressure); PMID 31423665, DOI 10.1002/ptr.6474 (systematic review and meta-analysis, blood lipids in angina pectoris). Research context, not a therapeutic claim.

Chinese Herb Notes

• How does corn silk differ from the other damp-draining herbs?

  It is the mildest and the most food-like of them, and the one with a Gallbladder and Liver reach. Most of the water-regulating herbs work on the Bladder and Spleen; corn silk’s Liver and Gallbladder entry is what gives it a bile-and-jaundice role alongside the urinary one, and makes it the natural partner rather than the rival of the classic jaundice herbs.

  • Versus Fu Ling — Fu Ling is bland and leaches dampness while also strengthening the Spleen and calming the spirit. Corn silk does none of the tonifying work; it simply drains, and drains downward.
  • Versus Che Qian Zi — both promote urination and clear heat from the urinary tract, but Che Qian Zi is cold while corn silk is neutral, so corn silk is the easier choice for prolonged use or a weaker patient.
  • Versus Yin Chen — Yin Chen is the principal jaundice herb, bitter and cool, and its diuretic action is weak. Corn silk approaches damp-heat in the Liver and Gallbladder from the opposite end: strongly diuretic and only mildly heat-clearing. They are traditionally used together for damp-heat jaundice rather than in place of one another.
  • Versus Jin Qian Cao — the classic stone herb. Corn silk shares the urinary-stone indication and is often combined with it, with corn silk contributing volume of urine rather than force.

  A note on the botanical name. The pharmaceutical Latin held here, Stylus Zeae Mays, names the style of maize. Modern literature calls the same material Stigma maydis or Maydis stigma, and Brazilian and European work refers to it as maize stigmas — useful to know, because searching under the wrong one of those names will find almost nothing.

  No formula held on this site contains corn silk, which is a fair reflection of its status: it is a folk and adjunct herb, used freely and in quantity, rather than a member of the classical formula canon. (Traditional context, not treatment advice.)

  Source: Sacred Lotus sources & references (the herb records for Yu Mi Xu, Fu Ling, Che Qian Zi, Yin Chen and Jin Qian Cao — nature, flavour, channels and category — as held on file); cross-referenced against multiple online sources and materia medica consensus; alternative botanical designations per PMID 22890173, PMC 6268265, DOI 10.3390/molecules17089697 and PMID 40984809, DOI 10.1002/bdr2.2526.