Did Henbane make Berserkers go Berserk?

A new study on the legendary Viking warriors known as berserkers suggests that they were able to achieve their battle trances and ferocity through the use of henbane.

The article by Karsten Fatur, an ethnobotanist from the University of Ljubljana, also offers evidence to refute the possibility that a particular type of mushroom was used by the Norse to become these warriors. The study was published earlier this year in the Journal of Ethnopharmacology.


Very little is known of the berserkers, but scattered accounts of them appear in sagas and Norse mythology. It is thought that the word berserker comes from “bear skin” because they wore animal pelts in battle. Fatur offers this description of them:

The berserkers were said to be not just ordinary warriors, but rather to fight while in a specific trance-like state, which was likely helpful in dissociating them from the close-up atrocities they would have seen and committed in battle. This state has been variously claimed to involve anger, increased strength, a dulled sense of pain, decreases in their levels of humanity and reason, behaviour akin to that of wild animals (including howling and biting on their shields), shivering, chattering of their teeth, chill in the body, and invulnerability to iron (swords) as well as fire. Additionally, they were said to attack enemies indiscriminately with no sense of friend or foe and to throw off their armour in battle.

Previous studies suggest that Amanita muscaria, a mushroom commonly called fly agaric, was used by the Norse to become berserkers. It is known that in Siberia this mushroom was dried and eaten during religious rituals to achieve a psychoactive state. However, Fatur believes that henbane, also known as Hyoscyamus niger, would be a more likely candidate for the Vikings to have used. This plant, which originated in the Mediterranean but spread northwards to Scandinavia, was well known in the Middle Ages to have psychoactive effects. It was even added to medieval beers, so much so that authorities banned that practice in 1507.


Fatur notes archaeological finds from Scandinavia that show henbane being used during the Viking age. This includes a woman’s grave from in Denmark from around the year 980 that included a pouch of henbane seeds with clothing, jewellery, and other grave goods that suggests she was a priestess or shaman.

The article offers this analysis of why henbane (Hyoscyamus niger) would have been more likely than mushrooms (Amanita muscaria):

As previously discussed, both substances may cause increases in strength, altered level of consciousness, wild/delirious behaviour, jerking/twitching, and redness of the face, all of which have been associated with berserkers. What makes Hyoscyamus niger a more compelling theoretical cause of the berserker state, however, is its additional symptoms that are not commonly seen in intoxications involving Amanita muscaria. In addition to the previous symptoms, H. niger’s alkaloids also have pain killing effects unseen in the compounds within A. muscaria, which may account for some of the reports of the supposed invulnerability of the Norse berserkers. Even more compelling is the duration of effects; though the berserker state has been reported to involve several days of side effects after the high has subsided, this is not a common feature in intoxications with Amanita muscaria.


Fatur also notes a few other effects that might have been caused by henbane, which has been seen in studies about modern cases of that plant use. These include the inability to recognize faces (berserkers were said to be not able to distinguish between friends and foes in battle), the removal of clothing, and loss of blood pressure, which might explain why berserkers did not lose much blood when struck by blades. There are some aspects of berserker behaviour which cannot be explained by using henbane, namely the chattering of teeth and the biting of shields.

Fatur hopes that future research will bring more insights into this topic. His article, “Sagas of the Solanaceae: Speculative ethnobotanical perspectives on the Norse berserkers,” appears in the Journal of Ethnopharmacology. You can read the article from his page.

Top Image: Berserker as a Lewis chessman – Photo © The Trustees of the British Museum



Sign up for our weekly email newsletter!