What is Hyeonggae?

Hyeonggae is a dried herb used in Korean medicine. It is the flower spike of a mint-family plant, Schizonepeta tenuifolia. You may also see it sold as Japanese catnip or schizonepeta spike.

Herb shops sell it as a single herb. It is used at the first sign of a cold. Think chills, a stuffy nose, a sore throat and a headache.

It is also used for itchy skin rashes, such as hives.

Here is the short verdict. No human trials have tested this herb on its own. Long use in a tradition is not proof that a herb works.

How does Hyeonggae work?

The honest answer is that no one knows how it works in people.

Lab and animal work gives a few clues. The oil in the herb may ease swelling and redness. It may also calm the itch signal that histamine sets off.

Histamine is a body chemical that drives hives and itchy skin.

Korean practice has its own view. It says the herb opens the surface of the body and pushes out wind. Wind is the old term for what brings on colds and rashes.

None of this has been shown in a human trial.

What forms does Hyeonggae come in?

Most people take Hyeonggae as a strong tea. The tea is made by boiling the dried, cut flower spikes. Add the herb in the last five minutes, since its oil boils away fast.

It also comes as a powder, as pills and as a liquid extract. A charred form, called hyeonggae-tan, is made by roasting the herb until it turns black. Korean practice uses that charred form for minor bleeding.

Most Korean recipes mix it with other herbs rather than use it alone. A common pairing is with bangpung (Saposhnikovia).

Where it comes from:

Hyeonggae is the Korean name for a herb used across East Asia. Chinese texts call it jing jie, and Japanese Kampo calls it keigai. Records of its use go back well over a thousand years.

In Korea it appears in the Donguibogam, a medical text from 1613. It sits in the group of herbs meant to clear the first stage of a cold. That role has not changed much since.

What does Hyeonggae help with?

• Early stage of a common cold: This is the main traditional use, and it is old and well documented. The herb is said to warm the body, bring on a light sweat and clear chills. No human trial has tested it alone for colds.
• Sore throat: Korean and Chinese recipes add it to throat formulas, often with other herbs. Evidence in people is missing. If your throat pain is severe, or you cannot swallow, see a doctor.
• Itchy skin rashes, such as hives: It is a standard herb in old rash formulas. Lab work shows some effect on histamine, the body chemical behind itch. That is a long way from proof in people, and no trial has tested the herb on its own.
• Headache that comes with a cold: Tradition pairs it with other herbs for a dull head and blocked nose. There is no trial evidence. A sudden, severe headache is not a job for herbs.
• Measles rash in children: Old texts used it to help a measles rash come out. This is history, not advice. Measles today needs medical care, and a child with a spreading rash and fever should be seen by a doctor.
• Minor bleeding: The charred form, hyeonggae-tan, was used for small bleeds such as nosebleeds. This rests on tradition alone. Bleeding that does not stop needs urgent care, not tea.

Which foods are rich in Hyeonggae?

1. Not found in everyday food: Hyeonggae is a medicine herb, not a kitchen herb

Practical Tips:

You will only meet it in herbal teas, powders and mixed formulas.

What are the side effects of Hyeonggae?

• Mild stomach upset or nausea
• Sweating more than you want to
• Dizziness or feeling light-headed
• Dry mouth
• Skin rash or allergy, more likely if you react to mint-family plants

Good to know:

Side effects are not common at normal tea amounts, and most are mild.

They usually stop when you stop the herb. Heavy sweating can leave you short of fluid, so drink water.

Stop at once and get help if your lips or face swell, or you find it hard to breathe.

How much Hyeonggae should you take?

• Recommended daily: A common adult amount is 3 to 9 grams of the dried herb a day, boiled as a tea. Korean and Chinese herb books set this range. No trial has tested a dose in people. Treat the range as custom, not proof. If you use a powder or extract, follow the maker's label. Strengths differ a lot between products.
• Best time of day: Taken warm and spread over the day, often as two or three small cups. Some people take a cup before bed to sweat lightly overnight.
• With or without food: Usually taken between meals. If it upsets your stomach, take it after food.
• Time to effect: Tradition says a light sweat and some relief within a few hours. No study has measured this in people.
• How long to take it: Short use only. For a cold, it is taken for a few days and stopped when symptoms pass. If you are no better after 7 days, or you get worse, see a doctor. There is no safety data for taking it for months.