Educational information, not medical advice — ask your doctor or midwife.
Track hyeoncho with reminders and record whether it helped, in the app.
Hyeoncho is the dried above-ground part of the plant Geranium thunbergii, a small wild geranium. In Korean herbal practice it is brewed into a tea and taken for loose stools, mild diarrhoea and an upset stomach. It is also sold as Thunberg's geranium herb.
It is used as a single drug (Korean) — meaning it is often taken on its own, not only as one part of a larger formula. The same plant is a well-known household remedy in Japan, where it is called gennoshoko.
Here is the honest verdict up front. Hyeoncho has a long and genuine traditional record in Korea and Japan, but good human trials are missing. Traditional use tells you that people have relied on it for a long time; it is not proof that it works, and this document does not repeat that point in every section.
Hyeoncho is what herbalists call an astringent — something that makes tissue feel tighter and drier.
It is rich in tannins (plant compounds that stick to proteins). In a test tube, tannins bind to proteins on the surface of the gut lining and may make it less leaky, which could slow watery stools. Tannins also slow the growth of some bacteria in laboratory dishes.
This is a plausible explanation, not a proven one. No one has shown in a proper human trial that this is what happens inside your bowel after you drink the tea.
The usual form is the dried, cut herb, simmered in water to make a decoction (a strong tea made by boiling). Loose dried herb and ready-made tea bags are the most common products in Korean and Japanese shops.
You may also see powdered herb in capsules and concentrated extract granules. These are stronger by weight than tea, so the amount on the label is not comparable to a spoonful of dried herb.
The herb is not used as an essential oil, and there is no injectable or standardised pharmaceutical form.
Hyeoncho has been used in Korean folk and traditional medicine for centuries as a simple remedy for diarrhoea and digestive upset. The same plant became a staple household medicine in Japan under the name gennoshoko, where it was listed in the national pharmacopoeia. Its standing rests on this long, documented everyday use in East Asia rather than on modern testing.
See a doctor if diarrhoea lasts more than two days in an adult, or more than one day in a child or older person. Get medical help straight away for blood in the stool, black tarry stools, high fever, severe stomach pain, or signs of dehydration such as dizziness, a very dry mouth or passing little urine. Also see a doctor if you feel unusually tired and pale, which can be a sign of low iron. Stop the herb and seek urgent help if you get a rash, swelling of the face or lips, or trouble breathing.
Evidence grades and traditional-use labels are explained in our methodology. Nothing here is medical advice.
What it is typically used for, usual dose, cautions, and the study behind it where real trial data exists.
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