Herb

Yu Mi Xu

Corn silk | 玉米须

Also known as:

Yù Mài Xū (玉麦须) , Bāo Gǔ Xū (包谷须) , Bàng Zi Máo (棒子毛)

Yu Mi Xu

Product appearance may vary from images shown

Properties

Dampness-draining herbs (利水渗湿药) · Neutral

Traditionally supports*

Urinary Health Blood Sugar Support Kidney Health Liver and Gallbladder Health Fluid Retention and Edema

Parts Used

Other

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Select Product Type

Select Supplier

Select Size

Quantity

$27.00 ($0.27/g)
For shipments to: United States Change
Standard Shipping (3-5 business days): $4.99
Express Shipping (1-2 business days): $9.99
Free shipping on orders over $75

About This Herb

Traditional Chinese Medicine background and properties

Herb Description

Corn silk is the silky, thread-like strands found on ears of corn. In Chinese medicine, it is a gentle, widely available herb used mainly to reduce water retention, support urinary health, and promote healthy Liver and Gallbladder function. It is mild enough for everyday use as a tea and is commonly recommended for people dealing with urinary difficulties, edema, gallstones, or blood sugar concerns.

Herb Category

Dampness-draining herbs (利水渗湿药)

Main Actions

  • Promotes Urination and Reduces Edema
  • Clears Damp-Heat and Resolves Jaundice
  • Calms the Liver
  • Benefits the Gallbladder
  • Lowers Blood Sugar

How These Actions Work

Promotes urination and reduces edema (利水消肿): Corn silk has a sweet and bland taste, which in TCM theory means it gently seeps Dampness downward through the urinary tract. It helps the body pass more urine, reducing fluid retention and swelling. This makes it useful for puffiness, bloating, and water retention from various causes, including kidney problems. Its action is mild, so it is typically used in larger doses (30-60g) or combined with other water-draining herbs for stronger effect.

Drains Dampness and relieves jaundice (利湿退黄): By promoting urination, corn silk gives the body's excess Dampness a pathway out. In TCM, jaundice (yellowing of the skin and eyes) is often caused by Damp-Heat obstructing the Liver and Gallbladder, preventing bile from flowing properly. Corn silk helps clear this Damp-Heat through the urine, which is why a classical TCM teaching says "to treat jaundice, do not forget to promote urination." Because corn silk is neutral in temperature rather than strongly cold, it can be used for both Heat-type (Yang) jaundice and Cold-type (Yin) jaundice.

Calms the Liver and benefits the Gallbladder (平肝利胆): Corn silk enters the Liver and Gallbladder channels. It helps smooth the flow of bile and ease Gallbladder conditions such as gallstones and cholecystitis. Its Liver-calming property also contributes to its traditional use for high blood pressure. Modern research has confirmed it can promote bile secretion and reduce bile thickness, supporting its classical cholagogue reputation.

Lowers blood sugar (降血糖): While not a classical TCM action category, corn silk has been used for centuries in folk medicine for what TCM calls "wasting and thirsting disorder" (消渴 xiāo kě), a condition that overlaps with diabetes. Modern pharmacological studies have confirmed that corn silk extracts can significantly reduce blood sugar levels.

Patterns Addressed

In TCM, symptoms cluster into recognizable patterns of disharmony that reveal what's out of balance in the body. Yu Mi Xu is traditionally associated with these specific patterns.

The following describes this herb's classification within Traditional Chinese Medicine theory and is provided for educational purposes only.

Why Yu Mi Xu addresses this pattern

Corn silk enters the Liver and Gallbladder channels and has a specific ability to drain Damp-Heat from these organs through urination. Damp-Heat in the Liver and Gallbladder causes bile to overflow, producing jaundice, and can also lead to gallstones and cholecystitis. Corn silk's bland, seeping nature draws this Damp-Heat downward and out through the Urinary Bladder, relieving the obstruction. Its neutral temperature means it clears Dampness without being overly cold, making it suitable even when the patient's constitution is not strongly heated.

A practitioner would look for one or more of these signs

Jaundice

Yellow skin and eyes from bile overflow

Gallstones

Pain in the right upper abdomen related to stones

Cholecystitis

Gallbladder inflammation with nausea and distension

Dark Urine

Scanty, dark-coloured urine

TCM Properties

Temperature

Neutral

Taste

Sweet (甘 gān), Bland (淡 dàn)

Channels Entered
Urinary Bladder Liver Gallbladder
Parts Used

Other

This is partial information on the herb's TCM properties. More detailed information is available on the herb's dedicated page

Product Details

Manufacturing, supplier, and product specifications

Product Type

Granules

Quantity Description

Loading quantity information...

Concentration Ratio

Loading concentration information...

Fabrication Method

Loading fabrication information...

Supplier Certifications

Loading certifications information...

Botanical & Sourcing

Quality Indicators

Good quality dried corn silk (Yu Mi Xu) forms loose, tangled clusters of fine, thread-like strands. The individual strands should be intact and complete, reaching up to 30 cm or longer, approximately 0.5 mm in diameter. The colour should be light green, yellow-green, or golden-brown with a subtle sheen and slight translucency. The texture should be soft and pliable, not brittle or crumbling. The stigma tip (bifid fork) should be visible at around 3 mm long. The taste should be faintly sweet and bland, with minimal aroma. Avoid material that is dark brown or black (indicating mould or over-aging), excessively fragmented, or mixed with husk debris and other impurities.

Primary Growing Regions

Corn (Zea mays) is cultivated throughout China and worldwide, so Yu Mi Xu does not have a single traditional "daodi" (terroir) region in the way that many classic Chinese herbs do. Major producing regions in China include the northeastern provinces (Heilongjiang, Jilin, Liaoning), as well as Shandong, Henan, Hebei, Sichuan, and Yunnan. The herb's earliest medicinal recording was in the Dian Nan Ben Cao from Yunnan province. Because corn silk is essentially an agricultural byproduct, quality depends more on the harvest timing and drying method than on geographic origin.

Harvesting Season

Summer to autumn. Corn silk can be collected when the corn is at the silking stage (when fresh silk first emerges), but it is most commonly gathered in autumn when the mature ears are harvested. Fresh silk is considered more potent; dried silk retains activity when properly processed.

Supplier Information

Treasure of the East

Loading supplier information...

Loading supplier attributes...

Miscellaneous Info

No additional information available

Usage & Safety

How to use this herb and important safety information

Important Medical Disclaimer

The information provided here is for educational purposes only and is not intended as medical advice or to replace consultation with a qualified healthcare professional. This herb is a dietary supplement and has not been evaluated by the FDA. It is not intended to diagnose, treat, cure, or prevent any disease.

Always consult with a qualified healthcare provider, particularly if you are pregnant, nursing, have a medical condition, or are taking other medications. Discontinue use and consult your healthcare provider if you experience any adverse reactions.

Recommended Dosage

Loading dosage information...

Instructions for safe storage and consumption

Loading storage and consumption information...

Traditional Dosage Reference

Standard

15–30g (dried); 30–60g (fresh)

Maximum

Up to 60–90g of dried herb in decoction for acute conditions (e.g. severe oedema, kidney stones), under practitioner supervision. Fresh corn silk can be used at double the dried dosage.

Notes

Standard doses of 15–30g are used for mild urinary difficulty, early-stage oedema, or as a general health tea. Higher doses of 30–60g are commonly used for more pronounced conditions such as nephritis-related oedema, gallstones, jaundice, or urinary stones. When used as a daily health tea, 3–5g of dried corn silk steeped in hot water is sufficient. Fresh corn silk is considered more active and should be used at roughly double the dried dosage. Because corn silk has mild blood-sugar-lowering effects, it is best not taken on an empty stomach in large amounts, especially by people prone to low blood sugar.

Toxicity Classification

Non-toxic

Yu Mi Xu is classified as non-toxic. Animal toxicity studies have shown no histopathological or adverse effects at corn silk concentrations of 8.0% consumed for 90 days. Clinical use over six months in chronic nephritis patients showed no toxic side effects. The main safety consideration is not toxicity per se, but the potential for electrolyte depletion (particularly potassium and sodium) with prolonged or high-dose use due to its diuretic action. No toxic components requiring special processing have been identified.

Contraindications

Avoid

Known allergy to corn or corn pollen. Individuals with corn allergy may experience skin rash, itching, or allergic reactions when using corn silk.

Caution

Pre-existing low blood pressure (hypotension). Corn silk may further lower blood pressure due to its diuretic and vasodilatory properties.

Caution

Pre-existing low blood potassium (hypokalemia). Corn silk's diuretic action can deplete potassium and may worsen electrolyte imbalances.

Caution

Concurrent use with pharmaceutical diuretics such as furosemide (Lasix). Combined use may cause excessive fluid and electrolyte loss.

Caution

Scheduled surgery within two weeks. Corn silk may affect blood sugar and blood pressure control during and after surgical procedures.

Caution

Concurrent use with anticoagulant medications (especially warfarin). Corn silk contains Vitamin K, which may reduce the anticoagulant effect.

Caution

People taking diabetes medication should use with caution, as corn silk may lower blood sugar and risk hypoglycemia when combined with antidiabetic drugs.

Special Populations

Pregnancy

Use with caution during pregnancy. While corn silk consumed in normal food amounts is generally considered safe, larger medicinal doses are not recommended. There are concerns that corn silk in high doses may stimulate uterine activity, potentially increasing miscarriage risk. Interestingly, one traditional folk application from the Quan Guo Zhong Cao Yao Hui Bian (National Compilation of Chinese Herbal Medicine) describes using corn silk tea to help prevent habitual miscarriage, but this should only be done under the supervision of a qualified practitioner. Pregnant women should avoid self-prescribing medicinal doses.

Breastfeeding

No specific adverse effects on breastfeeding have been documented. Corn silk consumed in food-level amounts is generally considered safe during breastfeeding. Notably, the earliest classical record in the Dian Nan Ben Cao specifically recommended corn silk for breast lumps and blocked milk flow, suggesting traditional practitioners considered it beneficial for lactation issues. However, there is insufficient modern research on the transfer of corn silk's active compounds into breast milk at medicinal doses. Nursing mothers should use standard decoction doses only under practitioner guidance.

Pediatric Use

Corn silk tea can be given to children in reduced amounts with practitioner guidance. Because of its mild diuretic properties, it may affect fluid and electrolyte balance in young children if taken regularly or in large quantities. For children over 5 years, a common approach is to use approximately one-third to one-half of the adult dose. It is traditionally considered gentle and safe enough for short-term paediatric use for conditions like urinary difficulty or mild oedema, but ongoing use should be monitored.

Drug Interactions

Diuretic medications (furosemide/Lasix, hydrochlorothiazide, bumetanide, torsemide, chlorothiazide): Corn silk has diuretic properties and may compound the fluid and electrolyte loss caused by pharmaceutical diuretics, potentially leading to excessive potassium depletion (hypokalemia) and dehydration. Electrolyte levels should be monitored.

Warfarin (Coumadin) and other anticoagulants: Corn silk contains Vitamin K, which promotes blood clotting. This may reduce the effectiveness of warfarin and similar anticoagulant drugs. INR should be monitored regularly if used concurrently.

Antidiabetic medications (insulin, glimepiride, metformin, glyburide, etc.): Corn silk has demonstrated blood sugar-lowering effects in both animal and human studies. Combined use with diabetes medications may cause blood sugar to drop too low (hypoglycemia). Blood glucose should be monitored closely.

Antihypertensive medications: Corn silk may lower blood pressure. Combined use with blood pressure medications could cause an excessive drop in blood pressure. Blood pressure should be monitored.

Anti-inflammatory corticosteroids: Some anti-inflammatory medications can decrease potassium levels. Corn silk may further reduce potassium, compounding the risk of hypokalemia when used together.

Dietary Advice

When using corn silk for its diuretic and dampness-draining effects, it is advisable to maintain adequate fluid intake to prevent dehydration. Eating potassium-rich foods (bananas, sweet potatoes, leafy greens) can help offset the mild potassium-depleting effect of prolonged use. Avoid excessive salty or greasy foods, which counteract its dampness-clearing actions. Because corn silk can lower blood sugar, avoid taking large medicinal doses on an empty stomach, and do not combine with large amounts of other blood sugar-lowering foods or supplements without monitoring.

Cautions & Warnings

Although this formula is typically safe for most individuals, it may cause side effects in some people. Pregnant women, nursing mothers, postpartum women, and those with liver disease should use the formula with caution.

As with any Chinese herbal remedy, it is advisable to seek guidance from a qualified TCM practitioner before beginning treatment.