Fu Zi

What is Fu Zi?

Fu Zi is the treated side root of a plant called Aconitum carmichaelii. It is one of the most poisonous herbs in Chinese medicine. It holds aconitine, a poison that can throw the heart out of its normal beat and stop it.

How safe it is depends on how the root is treated before use. Raw or badly treated root has killed people. Deaths and near deaths still happen, most often from home brews or from products bought online.

Chinese medicine ranks Fu Zi very highly. But long use in a tradition is not proof that a herb works, and it is not proof that it is safe. Good human trials are few, so we grade the evidence as insufficient.

This page is here to explain the danger. It gives no dose and no way to make or take the herb.

How does Fu Zi work?

Aconitine acts on sodium channels, the tiny gates that let salt move in and out of nerve and heart cells. It holds these gates open. Nerve and heart cells then fire when they should not.

That same action explains both the wanted effect and the harm. Nerves misfire, so the mouth and skin tingle and go numb.

The heart misfires, so the beat can turn fast, uneven and useless. Blood pressure can drop and breathing can fail.

There is no safe gap between the two. The amount that stirs the heart and the amount that harms it sit very close together. Small changes in the plant, the batch or the person can move a dose from active to deadly.

People also differ. Age, heart health, kidney health and other drugs all change the risk. This is why the herb is treated as a restricted medicine in many places, not a supplement.

What forms does Fu Zi come in?

Fu Zi turns up in a few forms. None of them is safe to use on your own.

Dried sliced root is sold in bulk by Chinese pharmacies. Ready made pills, granules and powders list aconite as one herb among many. Liquid extracts and tinctures are sold online, often with no test results.

Creams and plasters are sold for joint pain. Very dilute homeopathic products are a separate thing and hold little or no alkaloid (the plant chemical that causes the harm).

Whole herb formulas are the form most used by trained prescribers. Bulk root and online liquids are the forms most often linked to poisoning.

Heat, time and pairing with other herbs are all part of how prescribers handle this root. We do not describe any of that here, on purpose.

Where it comes from:

Fu Zi has been used in Chinese medicine for about two thousand years. It sits in the oldest herb books, and it stayed in use through every later era.

Doctors called it a warming herb. They gave it when a person felt deeply cold, weak and drained.

Classic texts from around 200 CE placed it in famous formulas for collapse, cold limbs and a faint pulse. It was often paired with other herbs that were said to soften its harshness.

Old writers knew it was risky. They wrote warnings about it and treated the root before use. Poisoning cases were recorded for centuries.

Trained practitioners in China, Japan and Korea still prescribe treated aconite today. It is handled as a potent drug there, with rules about who may supply it.

What does Fu Zi help with?

• Collapse with a faint pulse: Old texts used aconite for a person who was cold, sweating and fading, with a pulse you could barely feel. Today that picture means shock, and shock needs a hospital. No trial supports herbal care for it. Call emergency services instead.
• Weak heart and fluid swelling: Tradition used warming formulas with aconite for swollen legs and a weak, cold feeling body. Some small Chinese trials have tested such formulas in heart failure. The studies are small, poorly run and often unblinded, so they prove little. Heart failure has drugs with strong trial support, and they belong with a doctor.
• Cold type joint and back pain: Practitioners used aconite in pain formulas when cold and damp weather made the ache worse. Human data is thin. Some skin products with aconite have been studied for pain, with weak results. Oral use for aches has caused poisoning, including deaths.
• Long term watery diarrhoea: Old formulas used aconite when loose stools came with cold limbs and low energy. There is no good trial support. Long lasting diarrhoea needs a work up, because the cause can be treatable or serious.
• Low energy with a cold feeling: Being cold and tired was read as weak yang, and aconite was one answer. Modern testing can look for a thyroid problem, low iron, low blood sugar or sleep trouble. Those causes have clear treatments, and guessing with a poison is a poor trade.

What are the side effects of Fu Zi?

• Tingling or numbness in the mouth, tongue, lips and face
• A burning feeling in the mouth and throat
• Numb or tingling hands, feet and arms
• Feeling sick, being sick, belly pain and watery stools
• A fast, slow or uneven heartbeat
• Chest pain or a pounding feeling in the chest
• Low blood pressure, feeling faint, cold clammy skin
• Sweating and drooling
• Muscle weakness, so the legs will not hold you
• Trouble breathing
• Blurred vision, confusion and fits
• Heart rhythm failure and death

Good to know:

Aconite poisoning is an emergency. It is not a mild stomach upset.

Signs often begin within minutes. Most people who are poisoned feel it within two hours. Mouth tingling is a common first sign, and it can be followed fast by heart and breathing trouble.

There is no antidote. Hospital staff support the heart and breathing, treat the rhythm, and wait for the poison to clear. Some people need intensive care.

Harm has come from tiny amounts, from one cup of a home brew, and from products labelled as safe and treated.

Is Fu Zi legal where you live?

Aconite is restricted, not a free choice supplement. In the United Kingdom it is a restricted herb and cannot be sold freely to the public. In the United States it is not an accepted supplement ingredient, and the FDA has warned about products that hold it. In Australia it is banned from medicines sold to the public, apart from very dilute products. In mainland China, Hong Kong and Japan, treated aconite is a potent listed medicine that only trained prescribers may supply.

Options to discuss with a clinician

What to consider instead depends on why aconite was suggested. Talk each of these through with a doctor or a licensed practitioner.

If the worry is heart failure or swollen legs, see a doctor. There are heart drugs with strong trial support, and they are checked with blood tests and scans.

If you feel cold and tired all the time, ask for tests. A thyroid problem, low iron, low vitamin B12, poor sleep or low blood sugar can all do this, and each has a clear treatment.

If the problem is joint or back pain in cold weather, ask about heat, steady movement, physiotherapy and simple pain relief.

If you want a warming Chinese herb, a licensed practitioner can suggest far gentler ones, such as dried ginger or cinnamon bark, and check them against your drugs.

If a practitioner still believes aconite is right for you, it should come from a licensed, tested product and be prescribed and watched by someone trained to use it. Never buy it yourself and never adjust it yourself.

Graded pages for the options named above:

• Vitamin B12 — evidence grade A, traditional tier T0
• Ginger — evidence grade A, traditional tier T3