What is Senkyuchachosan?

Senkyuchachosan is a Japanese Kampo herb mix used for headache. Kampo is the Japanese branch of old Chinese herbal medicine. The mix is most often given for a headache that comes with a cold, or one that feels worse in cold, windy air.

It is one of the 148 Kampo formulas that Japan's MHLW (the Ministry of Health, Labour and Welfare) has approved for the national health insurance list. Doctors there may prescribe it as a dry granule. Shops also sell it without a prescription.

Here is the plain verdict on the evidence. The mix has been used for about 900 years, but we found no good human trials of it. Long use is not proof that a remedy works, and we say that once here rather than in every section below.

How does Senkyuchachosan work?

The honest answer is that no one knows. There is no human trial showing how it eases a headache.

In Kampo thinking, these herbs are warm and aromatic. They are said to drive out "wind-cold", the old name for the chill and stuffy head of a cold. That is a traditional idea, not a tested one.

Lab work has looked at single herbs from the mix. A few show mild pain-calming or blood-vessel effects in cells and animals. Whether any of that happens in a person who drinks the whole mix is unknown.

What forms does Senkyuchachosan come in?

The usual form in Japan is a dry granule or fine powder in a sachet. You stir it into hot water and drink it warm.

You can also find tablets and capsules. Some practitioners still make a loose-herb tea, which is the old way.

Strength varies a lot between brands. Check the label for how much of each herb you are getting, and keep the licorice amount in mind.

Where it comes from:

The recipe comes from a Chinese state pharmacy book of the Song era, the Taiping Huimin Hejiju Fang, published in the early 1100s. Its Chinese name is Chuanxiong Chatiao San.

Japanese doctors took it up as Kampo and it is still used there today. It has also been used in Korean medicine. That gives it standing across several traditions.

What does Senkyuchachosan help with?

• Headache that comes with a common cold: This is the main traditional use, and it is what the Japanese product labels list. Practitioners pick it when the headache sits with a runny nose, chills and a stiff neck. We found no controlled human trial testing it for this.
• Headache that feels worse in cold or windy weather: Classic Kampo texts match this mix to headaches that flare in cold air and ease with warmth. The reasoning is traditional pattern matching, not lab or trial data. Nothing in modern research confirms or rules it out.
• Repeated tension-type headache: Some Japanese doctors use it for long-running, dull headaches across the forehead or temples. Reports here are case notes and clinical habit rather than trials. If your headaches are frequent, you need a proper diagnosis first.
• Blocked nose and heavy head during a cold: The aromatic herbs and mint are traditionally used for a stuffy, heavy head. Any effect is likely mild and short. Do not expect it to shorten a cold, because that has not been tested.

Which foods are rich in Senkyuchachosan?

1. Licorice sweets and licorice tea: they add more glycyrrhizin on top of the dose in the mix
2. Green tea: part of the classic recipe, and a source of caffeine

Practical Tips:

Cut back on licorice sweets and licorice tea while you take this mix.

What are the side effects of Senkyuchachosan?

• Upset stomach, nausea or loss of appetite
• Rash or itching
• Swelling in the face, hands or legs
• A rise in blood pressure
• Low potassium (too little of the mineral potassium in your blood), which can cause muscle weakness, cramps and tiredness
• Heart rhythm changes, if potassium drops far enough
• Rare muscle breakdown (rhabdomyolysis), with muscle pain, weakness and dark urine, which can harm the kidneys
• Rare liver problems, with yellow skin or eyes and dark urine

Good to know:

Most people who take it for a short time have no trouble, and mild stomach upset is the usual complaint.

The serious effects come from the licorice root. Over weeks or months it can cause pseudoaldosteronism (a state where your body keeps salt, loses potassium and your blood pressure rises). Swelling, weight gain and muscle weakness are the warning signs.

This is a known, documented risk of licorice-containing Kampo, not a theory. Higher doses and longer use make it more likely.

How much Senkyuchachosan should you take?

• Recommended daily: In Japan the usual adult dose of the dry granule is about 7.5 g a day. You split that into two or three doses. Always follow the dose on your own pack, or the one your doctor sets. Brands differ in strength. Older adults and small people often need less. Do not give it to a child unless a doctor says so.
• Best time of day: Take it two or three times a day, before meals or between meals. Stir the granule into hot water and sip it warm if you can. Avoid a late dose if the green tea in it keeps you awake.
• With or without food: The usual way is on an empty stomach, about 30 minutes before a meal. If it upsets your stomach, take it with food instead.
• Time to effect: For a cold-type headache, some people feel easier within a few hours to a few days. For long-running headaches, judge it after two to four weeks. If you feel no change by then, it is likely not the right mix for you.
• How long to take it: For a headache with a cold, a few days is normal. If nothing changes in about a week, stop and ask a doctor. For headaches that keep coming back, review it with your doctor by one month. Long, non-stop use raises the risk from the licorice in the mix. If you use it for months, ask for a blood test to check your potassium level.