Corn Silk Tea: Benefits, How to Make It, Dosage & Side Effects

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Peel back the husk on an ear of fresh corn and you'll find a tuft of fine, pale threads, sometimes 30 centimeters (about 12 inches) long or more. That's corn silk. Each strand is part of the corn's female flower, there to catch pollen, and each one that's pollinated can grow into a single kernel.1 On the farm it's a leftover of the harvest, yet people in China, Turkey, France and the Americas have long saved it for medicine, brewing the dried strands into a mild, faintly sweet tea for bladder infections, swelling, kidney stones, prostate problems and bedwetting.1

That long record has earned corn silk a place in modern herbal medicine. It's listed in the Chinese Pharmacopoeia, and a 2025 draft herbal monograph from Europe's medicines regulator lists corn silk tea as a traditional herbal medicine for minor urinary tract complaints.83 Human research is adding to that picture, led by trials in which people drank the tea alongside their blood pressure medicine.2

Did you know?

• Maize was domesticated in Mexico some 9,000 years ago, and every part of the plant gets used, the silk included.1

• Corn silk starts out light green and turns red, yellow or light brown as it ages, and the sun-exposed brown tips carry more antioxidant phenolics than the pale strands closer to the ear.1

• In 1950s Poland, corn silk was prescribed as a tea of 30 grams steeped in 500 mL (about 2 cups) of water and sipped through the day, as a gentle diuretic for mild kidney and bladder inflammation.9

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What is corn silk?

In European herbal medicine, corn silk goes by the Latin name Maydis stigma. Romania's pharmacopoeia describes the dried strands as silky, golden-yellow to reddish-brown filaments up to 20 centimeters (about 8 inches) long, with a weak smell and a sweet, slightly mucilaginous taste, and herbal tradition gathers them from young, unripe ears, just before pollination.91 By dry weight, corn silk is about 56% carbohydrate and 15% protein, and in Southeast Asia it's regarded as a source of potassium salts.9

What ends up in your cup depends on how you make it. Alcohol extracts carry more of the flavonoids and phenolic acids, such as ferulic acid, than water extracts do, while a hot-water tea brings out the mucilage and the silk's small protein fragments.10911 Reviews of its makeup also list sterols and terpenoids.12

A short history of corn silk

In Chinese medicine, corn silk was first recorded by the physician Lan Mao, who lived from 1397 to 1470, in a materia medica of southern Yunnan.2 Native Americans used it for urinary tract infections, malaria and heart problems, and it became a traditional remedy in Turkey, France and the United States as well.1 A 1990 World Health Organization handbook of Vietnam's medicinal plants lists it as a diuretic for heart disease, high blood pressure, cystitis, kidney stones and diabetes at 20 to 30 grams a day.9

Europe has used corn silk tea as a diuretic for decades. A liquid extract appeared in the British Pharmaceutical Codex of 1923, the British Herbal Pharmacopoeia of 1983 listed corn silk for cystitis, urethritis, bedwetting and prostatitis, and two corn silk teas have been on the market in Poland since 1993 and 1994.9 On that record, the European Medicines Agency's herbal committee found in its 2025 draft assessment that corn silk tea meets its test for traditional use: at least 30 years of medicinal use, including 15 within the EU.9

Family recipes carried the tradition too. One published case describes a 9-year-old girl who had wet the bed every night of her life, despite several prescription treatments, and became dry after a corn silk tea made from her father's Native American grandmother's recipe, brewed from the silk of a dozen fresh ears.139

Corn silk in Chinese medicine

Chinese medicine uses corn silk to promote urination and drain what it calls dampness, a buildup of fluid in the body.2 The Chinese Pharmacopoeia places it along the stomach, kidney, liver and gallbladder channels, with actions that reduce swelling and clear heat from the liver and gallbladder, and Chinese practitioners have long added it to prescriptions for diabetes.6

What is corn silk good for?

How corn silk works in your body

Corn silk's best-mapped actions run through blood pressure and the kidneys. Steps 1 to 4 come from lab and rat studies; step 5 was measured in people.

A 2026 rat study points to a second route through the gut. Four weeks of corn silk extract lowered blood pressure in hypertensive rats, raised beneficial gut bacteria such as Akkermansia and Lactobacillus, and lowered inflammatory signals, and transplanting the treated rats' gut bacteria into other hypertensive rats reproduced the effect.24

Corn silk benefits, ranked by evidence

Ranked by the weight of the human research together with corn silk's traditional record, the tea's benefits start with blood pressure and urinary comfort, followed by blood sugar, kidney stones and cholesterol, with traditional and animal evidence for fluid retention, uric acid and the prostate.

Does corn silk tea lower blood pressure?

High blood pressure is something to act on, and I've made the point on my show that reducing stress is typically the single biggest factor in bringing it down.29 That's why my High Blood Pressure Protocol starts by calming the nervous system for two weeks, then refills potassium and magnesium from food, and why its daily drinks include water, hibiscus tea and green or herbal tea.7 Corn silk tea can be one of those herbal teas. For the rest of the food side, see the high blood pressure diet and foods that lower blood pressure.

The single-dose study shows how quickly the tea can act. In Benin City, Nigeria, 40 adults aged 42 to 54, 20 with untreated high blood pressure and 20 without, drank plain water one day and a corn silk water extract the next, at four doses spaced two weeks apart, without knowing the dose. The three higher doses, made from about 10, 15 and 21 grams of dried silk, lowered blood pressure significantly within 8 hours, with the biggest drop at about 3 hours and more effect at higher doses; the lowest dose, from about 5 grams, made no clear difference in the people with high blood pressure.159 Those amounts overlap the 8 to 12 grams used traditionally in Britain.9

The lab work is also why your prescriber should know about the tea: in lab tests, its peptides block ACE, the same enzyme that ACE-inhibitor drugs target, so if you take blood pressure medicine, read the safety section before you start.23

Can corn silk help a UTI, your kidneys or fluid retention?

In Ancient Remedies, I describe the root cause of a urinary tract infection, in Chinese medicine terms, as damp heat in the kidney and liver.30 Corn silk's role in that same system is the one described above: moving fluid and dampness out through the urine.2

Water comes first. In that book, my list of other remedies for a UTI starts with drinking 8 to 10 glasses of water a day, and the EU monograph pairs corn silk tea with the same advice: drink enough fluid to increase the amount of urine.303 For other natural approaches to bladder health, see D-mannose for UTIs, cranberries and overactive bladder.

If you have kidney stones, the five-herb trial above is the best human evidence, and its participants took the drops alongside their standard stone care.5 If you have kidney disease or have been told to limit fluids, the safety section comes first.

Corn silk tea and fluid retention

On my show, I've explained that a diet high in salt and processed foods causes fluid retention, and that sugar and alcohol do too.31 I've also put it simply: "Potassium causes your body to release water."31 So for puffiness, my advice is more fruit, beans and sweet potatoes, which tend to carry the most potassium, along with plenty of water at the same time.31 Our guide to potassium-rich foods lists the best sources, and cortisol face covers the stress side of facial puffiness.

Corn silk tea fits alongside those food changes as a gentle way to keep urine flowing, the role it has held in herbal medicine for centuries. Other herbs with the same traditional role are covered in natural diuretics and dandelion tea.

How to make corn silk tea

1. Measure: 2 to 4 grams of dried, cut corn silk. A level tablespoon of cut silk weighs about 3.4 to 4.5 grams.9

2. Simmer: Add it to 200 mL (about 7 ounces) of boiling water and keep it at a gentle boil for 5 minutes.3

3. Strain and sip: Strain out the silk and drink the tea between meals, up to 3 times a day.3

4. Drink water too: Keep your fluids up through the day; the tea works with plenty of fluid.3

The tea tastes mild and faintly sweet.1 If you'd like it sweeter, add a small spoonful of raw honey. Always start with boiling water: European assessors note that soaking corn silk in water, even when it's heated afterward, isn't a traditional preparation, because a soak can grow microbes and pick up mold toxins.9

If you save silk from your own corn, take the fresh, pale strands from young ears, and choose organic corn; in The Biblio Diet, corn is on my food list as organic only.32 The gram amounts above are for dried silk, which weighs far less than fresh.

When you buy dried corn silk, check for:

• The plant and part on the label: Zea mays, stigma, sometimes listed as Maydis stigma.

• Dry, clean silk: golden to reddish-brown, with no damp clumps or musty smell. In a test of supermarket herbal teas in Lisbon, corn silk samples carried fumonisin B1, a toxin from molds that grow on corn, at 50 to 150 micrograms per kilogram.33

• Organic: the same organic-only standard I set for the corn you eat.32

• Single herb or blend: many urinary and blood sugar teas mix corn silk with other herbs, and a blend is its own product.

How much corn silk tea should you drink?

The blood pressure and diabetes trials used far more silk than the EU's tea amounts, under medical care in China. The blood pressure trials lasted up to 12 weeks and the diabetes trial 3 months; the animal safety data are in the safety section.2634

Corn silk side effects & who should be careful

Animal safety studies tell a similar story. Rats fed a diet of up to 8% corn silk for 90 days, about 9.4 to 10.3 grams per kilogram of body weight a day, showed no harmful effects, and mice given a flavonoid-rich corn silk extract at up to 10 grams per kilogram a day for 28 days showed no toxicity or genetic damage.348 The one liver signal came from rats given a concentrated extract of corn silk bought at an open-air market, soaked in water and then boiled for 4 hours: over 28 days at 500 to 2,000 mg/kg, blood fats worsened, liver enzymes rose at the two higher doses, and the top dose caused degenerative changes in the liver.359 European assessors note that soaked preparations like this one aren't traditional; the traditional forms are the infusion and the decoction in the how-to section.9

Europe's drug-safety database holds no reports on corn silk, and the WHO's global database holds one: muscle inflammation in a man who was also taking insulin, two cholesterol drugs, guarana and vitamins, where the link to corn silk is uncertain.9

The bottom line

Corn silk: frequently asked questions

References

1. Hasanudin K, Hashim P, Mustafa S. Corn silk (Stigma maydis) in healthcare: a phytochemical and pharmacological review. Molecules. 2012;17(8):9697-715. doi:10.3390/molecules17089697 · PMID:22890173
2. Shi S, Li S, Li W, et al. Corn Silk Tea for Hypertension: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Evid Based Complement Alternat Med. 2019;2019:2915498. doi:10.1155/2019/2915498 · PMID:30792743
3. European Medicines Agency, Committee on Herbal Medicinal Products. European Union herbal monograph on Zea mays L., stigma. Draft. EMA/HMPC/509424/2023. Adopted for public consultation September 24, 2025 (4.1 traditional use: relief of symptoms associated with minor urinary tract complaints, with sufficient fluid intake; 4.2 decoction 2-4 g in 200 ml boiled 5 minutes, 2-3 times daily, 4-12 g a day; infusion 4-8 g in 200 ml, 3 times daily, 12-24 g a day; not under 12; see a doctor if symptoms last over 2 weeks; 4.4 fever, painful urination, spasm or blood in the urine need a doctor; not for conditions where reduced fluid intake is advised; 4.5 interactions none reported; 4.6 pregnancy and lactation not recommended; 4.8 undesirable effects none known).
4. Sahib AS, Mohammed IH, Hamdan SJ. Use of aqueous extract of corn silk in the treatment of urinary tract infection. J Intercult Ethnopharmacol. 2012;1(2):93-96. doi:10.5455/jice.20120525123150
5. Samandarian S, Soltani R, Hajhashemi V, et al. Efficacy of an Oral Solution Containing Five Herbal Extracts in the Treatment of Urolithiasis: A Randomized, Single-blind, Placebo-controlled Clinical Trial. J Res Pharm Pract. 2023;12(3):96-103. doi:10.4103/jrpp.jrpp_11_24 · PMID:38716323
6. Cheng Y, Chao H, Liu J, et al. Nontargeted metabolomic profiling analysis of patients with type 2 diabetes mellitus undergoing corn silk treatment. Medicine (Baltimore). 2024;103(33):e39396. doi:10.1097/MD.0000000000039396 · PMID:39151489
7. Axe J. The High Blood Pressure Protocol. DrAxe.com. 2026 (The Pressure Reset, five steps: Calm, days 1-14, including "If on medication, keep taking it exactly as prescribed"; Remineralize, days 10-30; Open; Move; Sustain, where medication is revisited with your prescriber as readings improve; p. 14, 7-day meal plan and daily drinks; p. 15, supplement protocol: "With kidney disease or a potassium-sparing, ACE, or ARB drug, clear potassium and supplements with your prescriber first"; p. 20, labs read against optimal ranges).
8. Peng KZ, Zhang SY, Zhou HL. Toxicological evaluation of the flavonoid-rich extract from Maydis stigma: Subchronic toxicity and genotoxicity studies in mice. J Ethnopharmacol. 2016;192:161-169. doi:10.1016/j.jep.2016.07.012 · PMID:27396347
9. European Medicines Agency, Committee on Herbal Medicinal Products. Assessment report on Zea mays L., stigma. Draft. EMA/HMPC/509423/2023. 2025 (sections 2.1-2.3 market and historical use in the EU since 1993-1994, BPC 1923, British Herbal Pharmacopoeia 1983, WHO monographs 1990 and 2010; 3.1 rat diuresis and electrolyte studies; 4.1-4.4 clinical data; 5.3 one VigiBase report; 6 traditional use conclusion).
10. Limmatvapirat C, Nateesathittarn C, Dechasathian K, et al. Phytochemical analysis of baby corn silk extracts. J Ayurveda Integr Med. 2020;11(3):344-351. doi:10.1016/j.jaim.2019.10.005 · PMID:32165017
11. Hsiang CY, Lo HY, Lu GL, et al. A novel heat-stable angiotensin-converting enzyme zinc-binding motif inhibitory peptide identified from corn silk. J Ethnopharmacol. 2024;320:117435. doi:10.1016/j.jep.2023.117435 · PMID:37979812
12. Wang Y, Mao J, Zhang M, et al. An Umbrella Insight into the Phytochemistry Features and Biological Activities of Corn Silk: A Narrative Review. Molecules. 2024;29(4):891. doi:10.3390/molecules29040891 · PMID:38398644
13. Kruesi MJ. Corn Silk Tea and Enuresis. J Child Adolesc Psychopharmacol. 2016;26(6):569-70. doi:10.1089/cap.2012.0125 · PMID:25329720
14. Shi S, Yu B, Li W, et al. Corn silk decoction for blood lipid in patients with angina pectoris: A systematic review and meta-analysis. Phytother Res. 2019;33(11):2862-2869. doi:10.1002/ptr.6474 · PMID:31423665
15. George GO, Idu FK. Corn silk aqueous extracts and intraocular pressure of systemic and non-systemic hypertensive subjects. Clin Exp Optom. 2015;98(2):138-49. doi:10.1111/cxo.12240 · PMID:25727941
16. Haldar S, Gan L, Tay SL, et al. Postprandial Glycemic and Insulinemic Effects of the Addition of Aqueous Extracts of Dried Corn Silk, Cumin Seed Powder or Tamarind Pulp, in Two Forms, Consumed with High Glycemic Index Rice. Foods. 2019;8(10):437. doi:10.3390/foods8100437 · PMID:31554322
17. Hu M, Zeng W, Tomlinson B. Evaluation of a crataegus-based multiherb formula for dyslipidemia: a randomized, double-blind, placebo-controlled clinical trial. Evid Based Complement Alternat Med. 2014;2014:365742. doi:10.1155/2014/365742 · PMID:24834096
18. Hu B, Yin T, Zhang J, et al. Effect of "maccog" TCM tea on improving glucolipid metabolism and gut microbiota in patients with type 2 diabetes in community. Front Endocrinol (Lausanne). 2023;14:1134877. doi:10.3389/fendo.2023.1134877 · PMID:36967788
19. Maksimović Z, Dobrić S, Kovacević N, et al. Diuretic activity of Maydis stigma extract in rats. Pharmazie. 2004;59(12):967-71. · PMID:15638089
20. Velazquez DV, Xavier HS, Batista JE, et al. Zea mays L. extracts modify glomerular function and potassium urinary excretion in conscious rats. Phytomedicine. 2005;12(5):363-9. doi:10.1016/j.phymed.2003.12.010 · PMID:15957371
21. Yuan L, Bao Z, Ma T, et al. Hypouricemia effects of corn silk flavonoids in a mouse model of potassium oxonated-induced hyperuricemia. J Food Biochem. 2021:e13856. doi:10.1111/jfbc.13856 · PMID:34250618
22. Kim SR, Ha AW, Choi HJ, et al. Corn silk extract improves benign prostatic hyperplasia in experimental rat model. Nutr Res Pract. 2017;11(5):373-380. doi:10.4162/nrp.2017.11.5.373 · PMID:28989573
23. Li CC, Lee YC, Lo HY, et al. Antihypertensive Effects of Corn Silk Extract and Its Novel Bioactive Constituent in Spontaneously Hypertensive Rats: The Involvement of Angiotensin-Converting Enzyme Inhibition. Molecules. 2019;24(10):1886. doi:10.3390/molecules24101886 · PMID:31100914
24. Yao G, Zhang T, Qin Z, et al. Corn silk extract as a prebiotic exerts antihypertensive effects via gut microbiota modulation in hypertensive rats. Microbiol Spectr. 2026;14(3):e0144225. doi:10.1128/spectrum.01442-25 · PMID:41569045
25. Lean ME, Leslie WS, Barnes AC, et al. Primary care-led weight management for remission of type 2 diabetes (DiRECT): an open-label, cluster-randomised trial. Lancet. 2018;391(10120):541-551. doi:10.1016/S0140-6736(17)33102-1 · PMID:29221645
26. Gumaih HS, Alasbahy A, Alharethi SH, et al. Antiurolithiasis activities of Zea mays extract and its mechanism as antiurolithiasis remedy. Am J Clin Exp Urol. 2023;11(5):443-451. · PMID:37941649
27. Al-Ali M, Wahbi S, Twaij H, et al. Tribulus terrestris: preliminary study of its diuretic and contractile effects and comparison with Zea mays. J Ethnopharmacol. 2003;85(2-3):257-60. doi:10.1016/s0378-8741(03)00014-x · PMID:12639749
28. Wang X, Dong L, Dong Y, et al. Corn Silk Flavonoids Ameliorate Hyperuricemia via PI3K/AKT/NF-κB Pathway. J Agric Food Chem. 2023;71(24):9429-9440. doi:10.1021/acs.jafc.3c03422 · PMID:37294890
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31. Axe J. The Truth About Cortisol Face and The Exact Steps To Fix It. The Dr. Josh Axe Show. 2026 (at 10:25 and 11:08; YouTube https://www.youtube.com/watch?v=7xJRhK-04k8&t=668s).
32. Axe J, Rubin J. The Biblio Diet. Hachette Book Group; 2025. ISBN 9781546008439 (vegetables list: "corn (only organic)").
33. Martins ML, Martins HM, Bernardo F. Fumonisins B1 and B2 in black tea and medicinal plants. J Food Prot. 2001;64(8):1268-70. doi:10.4315/0362-028x-64.8.1268 · PMID:11510675
34. Wang C, Zhang T, Liu J, et al. Subchronic toxicity study of corn silk with rats. J Ethnopharmacol. 2011;137(1):36-43. doi:10.1016/j.jep.2011.03.021 · PMID:21397679
35. Ikpeazu VO, Ugbogu EA, Emmanuel O, et al. Evaluation of the safety of oral intake of aqueous extract of Stigma maydis (corn silk) in rats. Acta Sci Pol Technol Aliment. 2018;17(4):387-397. doi:10.17306/J.AFS.0601 · PMID:30558395
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38. Caixeta GAB, Dos Santos Reis D, Soares KI, et al. Toxicological Assessment of a Standardized Dry Extract of Zea mays L. (Poaceae) Stigmas During Gestation: Effects on Maternal Parameters and Fetal Outcomes in Wistar Rats. Birth Defects Res. 2025;117(9):e2526. doi:10.1002/bdr2.2526 · PMID:40984809
39. Lee EY, Kim SL, Kang HJ, et al. High maysin corn silk extract reduces body weight and fat deposition in C57BL/6J mice fed high-fat diets. Nutr Res Pract. 2016;10(6):575-582. doi:10.4162/nrp.2016.10.6.575 · PMID:27909554

Dr. Josh Axe, DC, DNM, CNS

Doctor of Natural Medicine · Founder, DrAxe.com

Dr. Axe is a certified doctor of natural medicine, clinical nutritionist, and multiple New York Times bestselling author. He has spent 20+ years in clinical practice helping people heal at the root cause and founded one of the most-visited natural-health platforms in the world.

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