Monkshood Poisoning

Medically Reviewed by Dany Paul Baby, MD on November 04, 2022
5 min read

Monkshood, also commonly called wolfsbane, has appeared throughout human history — notably in European, especially Greek, myths. This plant has pretty purple flowers but also a dangerous secret.

Monkshood is a general term used to refer to plants within the genus Aconitum. Other common names of this plant include aconite, devil’s helmet, queen of poisons, and wolfsbane. It's a wildflower mainly found in the northern hemisphere in the forests and creek banks of mountainous areas.

People have used monkshood throughout history as an herbal treatment. Some examples of medicinal monkshood use include:

  • Internally as a sedative
  • Internally to induce sweating and lower fever during illness
  • Internally to slow heart rate in cases of heart palpitations and heart swelling
  • Topically as a local anesthetic

People still use monkshood in some areas of the world as a traditional medicinal treatment. Traditional Chinese and Indian medicine have found methods to process monkshood so that it's safe to use.

The term “monkshood” comes from the sepal, the outer part of the flower that covers the bud as it develops and supports the petals. The sepal on monkshood resembles the cowl that monks used to wear. Monkshood identification is easiest when the flowers are blooming.

There are over 250 species in the Aconitum genus, but most of them share similar characteristics.

The flowers of monkshood plants bloom in the summer and come in shades of blue, purple, and white. They typically grow in vertical groups, called racemes. The flowers have the characteristic hood look that gives them their name.

The leaves of monkshood plants can vary widely among species. They're typically dark green and lobed, meaning that they aren’t one round shape but branch into sections around a central point. The leaves and flowers grow from a rigid, upright stem.

All parts of raw monkshood plants are extremely poisonous. Most severe poisonings happen as a result of ingesting monkshood, but you can also easily absorb the poison through the skin. 

While monkshood does have some therapeutic benefits, it doesn’t take much to cause poisoning. You should only take monkshood medicinally under the care of a medical professional.

The alternative names of monkshood give an indication of its toxicity. 

There is speculation that the Latin name for the genus, Aconitum, comes from the Greek word akon, meaning “dart” or “javelin.” These weapons would be poisoned with these plants to deliver a more deadly injury. The term “wolfsbane” came about because the plant was used to poison wolves in Europe.

Monkshood contains several compounds that are toxic to humans, most notably aconitine. Aconitine mainly affects the heart but also affects the nervous system.

Aconitum plants have appeared as a poison throughout history, especially within Greek mythology:

  • Athena used aconite to turn Arachne into a spider.
  • Madea tried to trick King Aegeus into killing his son Theseus with tea poisoned with aconite.
  • Madea’s mother Hecate is said to have discovered the poison and used it to kill her father.
  • The fourth Roman emperor, Claudius, is rumored to have been poisoned with aconite by his wife Agrippina.

Modern cases of aconite poisoning warn us of the toxicity of the plant as well. The first documented homicide case involving aconitine poisoning happened in 1881 when George Henry Lamson was convicted of murdering his brother-in-law.

Most cases of aconitine poisoning are the result of someone trying to use monkshood plants for their therapeutic effects. Other common causes of monkshood poisoning include confusing the plant for something edible or children eating the plant.

Aconitine poisoning can cause severe illness and death. Monkshood poisoning symptoms can start minutes to hours after contact with the plant and may include:

  • Abdominal pain
  • Chest pain
  • Diarrhea
  • Dizziness
  • Heart rhythm changes
  • Nausea
  • Numbness
  • Shortness of breath
  • Tingling
  • Vomiting
  • Weakness

Death due to monkshood poisoning is usually caused by abnormal heart rate and difficulty breathing.

If you discover that you or a loved one have come into contact with monkshood, seek emergency help right away. 

If the person who came into contact with the monkshood is unconscious or in distress, call 911.

If the person is conscious, contact Poison Control through their online tool or by calling the toll-free hotline at 1-800-222-1222. Try to give them as much information as possible, including:

  • Age of the person who swallowed the plant
  • Weight of the person who swallowed the plant
  • Current condition of the person who swallowed the plant
  • If the person ate or touched the plant
  • What part of the plant the person ate/touched
  • How much they ate or how long they touched the plant for
  • How long ago the person had contact with the plant

Because even small doses of monkshood can cause illness, Poison Control will likely recommend a hospital visit. 

There is no cure or antidote for monkshood poisoning. Monkshood poisoning treatment mainly serves to support the body and manage symptoms. Your medical care team will monitor your vitals, especially your breathing, blood pressure, and heart rate. They may use medications and therapies to help regulate any issues that arise.

Treatment and recovery time will depend on many factors, most significantly, how much monkshood was ingested:

  • A 66-year-old woman drank an herbal tea with monkshood and needed four hours of medication and electric shocks before her heart rate was normal again.
  • A 21-year-old man made himself capsules of dried monkshood to treat his anxiety. One night, he took three before bed and awoke with symptoms of poisoning. When he arrived at the hospital, his heart rate was 43 beats per minute. He had to stay in the hospital for 48 days.
  • An 81-year-old couple used herbs from their garden to make a salad and accidentally included monkshood. When the man arrived at the hospital, he was in cardiorespiratory arrest but was resuscitated. The woman had severe vomiting, low blood pressure, and a heart rate of 200 beats per minute. After treatment with medication, she recovered.
  • A 25-year-old-man ingested monkshood with berries while on a walk. His symptoms started with nausea and vomiting, and he eventually collapsed about three hours after ingesting the flowers. He did not survive.

The hooded flowers of monkshood are fairly distinct. Sometimes, monkshood may be confused with larkspur, which also has purple flowers on a raceme, but larkspur doesn’t have the hooded flowers that monkshood has. Like monkshood, larkspur is poisonous. To stay safe, avoid any plant that resembles monkshood unless you know for certain that it’s safe.