The medicinal power of tansy

Tansy is native to Europe and a large part of Northern Asia. The plant grows to a height of 60 to 120 centimeters and has yellow flowers. In the past, tansy was planted near kitchen doors. The reason for this is that ants do not like this plant. Tansy could prevent ants from entering the house. Tansy is a plant that has medicinal properties. It has traditionally been used against fleas, lice and intestinal worms. It is a plant with side effects; therefore only use it under the supervision of a herbal therapist. NB! This article is written from the personal view of the author and may contain information that is not scientifically substantiated and/or in line with the general view.

Botanical drawing tansy / Source: Prof. Dr. Otto Wilhelm Thomé (1840–1925), Wikimedia Commons (Public domain)


  • Naming
  • Traditional use tansy
  • Active substances
  • Tansy repels worms
  • Tansy, good for digestion
  • Other medicinal effects of tansy
  • Dose and safety
  • Visit a doctor or herbal therapist


In Latin, tansy is called Tanacetum vulgare . In Dutch, this plant has some alternative names: Reinevaar, Reinvaan, Reinvaren, Wormkruid, Kruidwis, Kostkruid, Tente, Stonefern, Wormzaad, Zilverknotjes and Thunderbloemen. The word ‘worm’ in the name of this medicinal plant refers to its medicinal effectiveness against internal worms such as tapeworm; these are displaced by tansy. Tanacetum is a name derived from Athanasia, which means ‘immortal’. Tansy is associated with immortality in two ways. Firstly, the flowers remain beautiful much longer than other flowers and secondly, this plant has long been an ingredient in a life drink; a drink that should protect you from all kinds of diseases so that you live as long as possible.

Traditional use tansy

In folk medicine, tansy has always been a remedy for the stomach, kidneys and bladder. Rheumatism and gout were treated with it, but worms could also be expelled with it. Tansy was known in the Middle Ages as one of the nine most commonly used herbs to prevent spells. Anyone who drank a cup of tansy tea on Easter Monday did not get a fever all year long. On the other hand, wizards and sorceresses used the plant to make thunder; hence the nickname thunder flowers.

Active substances

The whole herb, the flowering tops or just the flower is used for phytotherapeutic purposes. It contains the following important active ingredients: essential oil with the ketone thujone, the bitter substances tanacetin I and II and flavonoids.

Tansy repels worms

The anthelmintic effect of tansy is its most important medicinal property. It is a very effective remedy, actually a little too effective; it has side effects. It is rarely used today to expel worms. This plant contains thujone in large quantities and the percentages can differ from plant to plant; therefore, it is not easy to use tansy as medicine. In the past it was mainly used for:

  • Ascaris or roundworm,
  • Oxyures or ass maggots.

Tansy, good for digestion

When tansy is used in large quantities, for example two grams, it can be a wonderful remedy for all kinds of digestive problems. It is a bittering agent and, like almost all bittering agents, it is good for the functioning of the liver. If the liver works better, the entire digestive process will benefit. Tansy is an antispasmodic, stomach tonic and carminative. It is a phytotherapeutic medicine for:

  • Appetite loss or anorexia,
  • Meteorism or abdominal distension,
  • abdominal cramps,
  • Migraine,
  • Neuritis or nerve inflammation.

Other medicinal effects of tansy

  • The antispasmodic effect makes tansy an emmenagogue; a menstrual stimulant.
  • It has always been used in folk medicine for amenorrhea or absence of menstruation.
  • It was considered a general tonic; There is something in that in itself because this digestive-strengthening herb ensures that nutrients are absorbed more efficiently.

Dose and safety

There are a number of ways to use this medicinal plant:

  • Tea or infusion: In the morning on an empty stomach, gently boil two grams of flowering tops in 200ml of water and then drink.
  • Add two to four grams of spice powder to a fruit puree or marmalade to mask the bitter taste.

With normal use, in the therapeutic dose as indicated above, no side effects are expected. However, one plant has more thujone than the other. Because of this unpredictability and the risks it entails, the use of tansy has been almost completely abandoned. Tansy essential oil should never be used on or in the body. Thujone can cause a serious reaction, especially to the nervous system. In the past, the essential oil was used to force an abortion, but because it has strong side effects, this is no longer done. Symptoms of thujone overdose include:

Tanacetum vulgare / Source: Penarc, Wikimedia Commons (CC BY-SA-3.0)

  • Vomitus or vomiting,
  • Painful gastrointestinal cramps,
  • Gastroenteritis or gastroenteritis,
  • Reddening of the face,
  • Cramps,
  • Unconsciousness,
  • Difficult and accelerated breathing,
  • Irregular heartbeat,
  • Dilated pupils,
  • Uterine bleeding,
  • Abortion,
  • Kidney damage with bleeding,
  • Liver damage.

Visit a doctor or herbal therapist

Much of the information about the medicinal plant mentioned in this article comes from the book Groot Handboek Medicinal Plants by Geert Verhelst. That is a handbook in phytotherapy. However, it is not suitable for self-healing. Anyone who suffers from something should consult a doctor or herbal therapist for a good diagnosis and choice of the best remedies, tailored to your personal situation. The knowledge and science mentioned here is of a purely informative nature.