Wormwood is an herb and the main ingredient in the alcoholic drink absinthe. It may have medicinal properties. However, its active ingredient, thujone, is toxic and can pose a health risk if people take it long term or have a health condition.

In this article, we examine wormwood and its chemical properties. We also look at the benefits and risks of consuming wormwood and the appropriate dosage.

Engraved drawing of a plantShare on Pinterest
mikroman6/Getty Images

Artemisia absinthium L., commonly known as wormwood, is a perennial shrub from the Asteraceae family of plants. It has deeply lobed, grayish-green leaves and small yellow flowers that bloom in July and August. It is an aromatic plant with a potent sage odor and bitter taste.

Herbalists and manufacturers use wormwood leaves and smaller stems to make medicines. There are many artemisia species, but people often use Artemisia absinthium L. and Artemisia annua L., or sweet wormwood, for medicinal purposes.

Historically, people have used wormwood to treat a wide range of ailments. According to a 2020 article, wormwood’s confirmed biological activities include:

  • stimulating digestion and appetite
  • being antiparasitic
  • inhibiting the growth of protozoan infection
  • having antibacterial properties
  • being antifungal
  • being anti-ulcer
  • preventing damage to the liver
  • being anti-inflammatory
  • having antioxidants
  • stimulating the immune system
  • having the ability to damage cancer cells
  • being a pain reliever
  • protecting nerve cells against damage
  • being an antidepressant
  • reducing mental confusion
  • stabilizing cell membranes

Wormwood has numerous compounds responsible for its biological activities, including:

  • essential oils
  • bitter sesquiterpene lactones
  • absinthin isomers
  • bitter compounds, such as artemisinin
  • phenolic acids
  • flavonoids
  • coumarins

The most well-known active ingredient in wormwood is thujone. Wormwood contains two types of thujone called alpha thujone and beta thujone. The alpha form is more toxic than the beta form.

Animal research investigating wormwood’s neurotoxicity shows that alpha thujone could cause convulsions and death at higher doses.

Wormwood has the following potential uses and benefits:

Absinthe drink

Wormwood is the active component in the alcoholic drink absinthe. The U.S. government banned absinthe in 1912 because it believed it was hallucinogenic.

Since 2007, retailers can sell the beverage, provided its thujone level is below 10 parts per million, which they label as thujone-free. Additionally, the Food and Drug Administration (FDA) allows manufacturers to use wormwood as a food additive, provided it has no thujone content.

Treating parasites and digestive disorders

People in Asia and Europe used wormwood traditionally for treating gastrointestinal disorders and expelling worms and parasites. Today, herbalists use wormwood to improve digestion and hypoacidity or lack of appetite.

A 2018 review explains that the bitter compounds in wormwood can stimulate gastric juices and bile and improve blood flow in the digestive system. It also suggests that the herb can force out parasitic organisms and act against several pathogens.

Treating inflammatory conditions and immune disorders

A 2017 study indicates that topical treatment with wormwood is comparable to piroxicam gel for knee osteoarthritis. Study participants had no pain after 2 weeks of treatment with wormwood ointment.

Another animal study found that wormwood has significant pain-relieving and anti-inflammatory effects due to its flavonoids.

According to a 2017 review, studies indicate that wormwood may also be beneficial for treating inflammation associated with Crohn’s disease. Furthermore, wormwood may inhibit the growth of human breast cancer cells.

Scientists have also examined wormwood’s effects on the immune system and cells, and they suggest it may be effective for treating immune disorders, intracellular viruses, and bacterial infections.

Treating tuberculosis

In 2019, researchers investigated wormwood’s effects on tuberculosis (TB) in animals. The authors found that extracts may be effective against mycobacterial infections that cause TB and are not toxic to animals.

Offering antidepressant and brain-protective effects

A 2020 review indicates that wormwood supports the formation of the body’s antioxidant glutathione and is protective of the brain. It notes that animal studies suggest wormwood has an antidepressant effect and may increase serotonin.

Another review suggests that wormwood may benefit those with neurological diseases, such as Alzheimer’s or Parkinson’s, and may have properties that reduce confusion, delirium, and disorientation.

However, researchers need to conduct more human research to confirm these effects.

Balancing blood sugar

Research suggests that wormwood may be beneficial for balancing blood sugar and insulin.

Additionally, some research suggests that wormwood may prevent the accumulation of lipids in the blood and reduce blood sugar levels in people with type 2 diabetes and hyperlipidemia.

Studies indicate that thujone in wormwood may cross the blood-brain barrier and affect the nervous system. In animal experiments, thujone causes convulsions and affects fertility. Studies warn that people should avoid it during pregnancy.

According to a 2021 review, wormwood may cause allergic reactions, including rhinitis and dermatitis, through contact with the skin, digestion in tea, or pollen.

However, another review suggests that wormwood is only toxic when used long term, and short-term use shows low toxicity.

If a person has a health condition or takes medication, they should speak with a healthcare professional before consuming wormwood products. People should not take wormwood during pregnancy.

There is no expert advice about wormwood dosages, and the FDA prohibits its active ingredient, thujone.

People can take wormwood as a liquid tincture, tablet, or dried herb. It is also available as a tea and an ingredient in absinthe.

A person should speak with a healthcare professional before taking wormwood, particularly if they have a health condition or are taking medication.

Wormwood has a long history of traditional use, and scientists today are interested in investigating its potential. Its herbal properties are wide-ranging, and its potential clinical benefits include supporting digestion and expelling parasites. It may also be beneficial for inflammatory or immune conditions.

However, its active ingredient, thujone, is toxic, and there is no guidance on how much is safe to use. Additionally, the FDA prohibits thujone in foods and beverages, so people must seek medical advice before taking wormwood.