What is Keishikaryojutsubuto?

Keishikaryojutsubuto is a Japanese Kampo herbal formula that contains aconite root (bushi). Aconite holds heart toxins with a very small safety margin. Poisoning can cause a deadly heart rhythm, so the formula is prescribed by doctors in Japan and restricted in many other countries.

The name means Cinnamon Twig Decoction with poria, atractylodes and aconite added. A doctor or pharmacist dispenses it for stubborn joint and nerve pain. It is not a self-care remedy, and this page gives no dose and no way to make it.

The formula also contains licorice (kanzo). Licorice can lower potassium, a body salt the heart needs. Low potassium makes aconite heart rhythm trouble more likely, so the two risks stack.

Evidence verdict: we found no human trials of this formula. Most of the human record is poisoning case reports.

The formula does hold a settled place in Kampo practice. Long use in a tradition is not proof that a remedy works, or that it is safe.

How does Keishikaryojutsubuto work?

Start with the harm. Aconite alkaloids (strong plant chemicals) act on sodium channels. These are tiny gates that let salt particles move into nerve and heart cells.

Lab and animal studies show the alkaloids hold these gates open. Nerve and heart cells then fire when they should be quiet.

In people, this shows up as tingling, numbness and vomiting. It can also set off ventricular tachycardia (a very fast, dangerous heartbeat). At high levels the heart can stop.

Licorice adds a second problem. It can push potassium (a key body salt) out of the blood. A heart low in potassium is more likely to fall into a bad rhythm.

Now the claimed benefit. In Kampo theory, the formula warms the body and drives out cold and damp from the joints. That is a traditional model, not a tested mechanism.

In animal and lab work, aconite alkaloids appear to dull pain signals. Whether that helps patients at levels that stay safe is not settled.

What forms does Keishikaryojutsubuto come in?

In Japan the formula comes as a pharmacy granule, powder or tablet, given on prescription. Raw herb packets are also used in clinic practice.

Every form contains aconite. The form does not make it safe. A neat granule sachet carries the same class of risk as loose herbs.

Some online sellers ship look-alike products from other countries. These are often not checked to the same standard. Alkaloid content can swing widely between batches.

Do not buy aconite-containing products online. This page names no seller and no source on purpose.

Where it comes from:

Kampo is the Japanese school of herbal medicine, built on old Chinese texts. Cinnamon Twig Decoction comes from the Shanghan Lun, a Han dynasty Chinese work.

Japanese practitioners later added poria, atractylodes and aconite. They used the result for pain that felt worse in cold, wet weather. It was chosen for people judged cold, tired and weak in the limbs.

Aconite was known as a poison for as long as it was known as a drug. Old texts treated it with care and paired it with other herbs said to soften it.

Japan's health ministry later approved the formula as an ethical Kampo medicine. That approval put it in the hands of doctors and pharmacists. It was never meant for home use.

What does Keishikaryojutsubuto help with?

• Joint pain that feels worse in cold, damp weather: This was the classic Kampo use. Practitioners picked it for aching, stiff joints in people who felt cold. We found no controlled human trials for this use. So the claim rests on practice reports, not on tested results.
• Neuralgia (nerve pain): Kampo prescribers have used it for shooting or burning nerve pain in the limbs. No human trial of this formula for nerve pain was found. Aconite alkaloids dull pain signals in animal studies, but that does not show benefit in people.
• Long-term low back pain: Traditional texts linked back pain of this type to cold and damp. The formula was given to warm and move. Evidence in people is missing. Standard care for back pain has been studied far better and is much safer.
• Stiff, aching shoulders, arms and legs: Practitioners used it for heavy, stiff limbs with poor tolerance of cold. There is no trial support. Stiffness with swelling can also signal a treatable joint disease, which needs a proper diagnosis first.
• Cold, painful hands and feet: The formula was seen as warming, so it was used for cold extremities with pain. No human trials were found. Cold, painful hands and feet can point to circulation, thyroid or nerve problems, so see a doctor rather than self-treat.

What are the side effects of Keishikaryojutsubuto?

• Tingling or numbness in the mouth, tongue, face or hands
• Nausea, vomiting or stomach pain
• Racing, pounding or uneven heartbeat
• Ventricular tachycardia (a very fast, dangerous heart rhythm)
• Chest pain or trouble breathing
• Low blood pressure, dizziness or fainting
• Cold, clammy skin and heavy sweating
• Muscle weakness or trouble moving the limbs
• Blurred vision or confusion
• Low potassium (a key body salt) from the licorice in the formula
• Swelling of the ankles, weight gain and raised blood pressure from licorice
• Skin rash or itching
• Rare liver injury, seen with some Kampo products
• Death, in serious aconite poisoning

Good to know:

Aconite poisoning is an emergency, not a side effect to wait out. Signs often begin within minutes to two hours.

Tingling of the mouth or hands is a classic early warning. Vomiting, a racing heart or fainting means the heart may already be affected.

Get emergency care at once. Do not take another dose to see what happens.

How much Keishikaryojutsubuto should you take?

• Recommended daily: This page gives no dose, and that is on purpose. The gap between a traditional amount of aconite and a poisoning amount is very small. People have been harmed at or near amounts once treated as normal. Strength also varies between batches and between products. A number printed on a web page cannot account for that. Only a prescriber who knows the exact product, your health and your other medicines can judge this. If a doctor or pharmacist has prescribed it for you, follow their instructions and nobody else's.
• Best time of day: Not applicable. Advice on timing is part of dosing, and this page gives none.
• With or without food: Not applicable. Food advice belongs to a prescription that a clinician has given you in person.
• Time to effect: Not applicable. We do not describe how fast it works, because that invites self-testing. One timing fact does matter for safety. Signs of aconite poisoning can start within minutes to about two hours.
• How long to take it: Not applicable. This page sets no length of use. Supervised use is reviewed and stopped by the prescriber. Unsupervised use has no safe length, because harm can come on the first day.