In 1784 a Swedish professor named Samuel Ödman suggested that Nordic Vikings used Fly Agaric Mushrooms (Amanita muscaria) to enter the Berserker Rages. He based his theories on reports about the use of fly agaric among Siberian shamans.

The notion has become widespread since the 19th century, but no contemporary sources mention this use or anything similar in their description of berserkers. Today, it is generally considered an urban legend or at best speculation that cannot be proven. On the whole, muscimol, the psychoactive, ingredient, is a mild relaxant, but it is widely known, as with all drugs that it can create a range of reactions within a range of people and it is possible that it could make a person incredibly angry, as well as make them "very jolly or sad, jump about, dance, sing or give way to great fright".


Ramsbottom (1953) described in more detail the use of these mushrooms by the Berserkers. According to him, fly-agaric or bug-agaric were poisonous but not deadly and did not kill healthy people. The potency varied with district. In some districts of France these mushrooms are regularly eaten. S. Odman, in 1784, first suggested that Vikings used fly-agaric to produce their berserk rages. Ramsbottom cited 12 authors who referred to the use of these mushrooms by the Siberian tribes already mentioned. The Koryaks believed a person drugged obeyed the wishes of spirits residing in them. Fabing (1956) and Fabing and Hawkins (1956) was convinced the Berserkers did, indeed, use fly-agaric. It is a very plausible explanation. Going berserk occurred as follows. The Norse took the mushrooms so that the effect came on during the heat of battle or while at work. During the berserk rage they performed deeds which otherwise were impossible. The rage started with shivering, chattering of the teeth, and a chill. Their faces became swollen and changed color. A great rage developed in which they howled like wild animals and cut down anyone in their way, friend or foe alike. Afterward their mind became dulled and feeble for several days. In 1123 AD a law was passed making anyone going berserk liable for several years in jail. It was not heard of since. Fabing quoted Drew who described a modern reaction to _Amanita muscaria._ A patient ate some of the mushrooms at 10:00 PM. Two hours later he developed diarrhea, sweating, vertigo, and salivation. He fell asleep but was awake at 2:00 AM disoriented, irrational, and violent. ON admission to hospital he was cyanotic, responded to pinpricks but not to deep pain. He was disoriented in all three spheres. Somnolence alternated with excitement. He thought he was in hell. He spoke continually and irrationally of religious matters. A physician was misidentified as Christ. When not in hell he was convinced he was in Eden. That evening his mental state cleared and next morning he was normal.



Berserker Rage Amanitas

To the contrary, weve also read:

Today, one still finds repeated in the literature, where the idea is perpetuated and passed on without reflection, the thesis that the berserkers acquired their enormous power and their legendary courage, the so-called berserker madness or furor teutonica, through their use of fly agaric. But the psychoactive effects of the fly agaric more closely resemble opium and the user will seldom experience anything more than a euphoric state with certain synaesthetic visions. The fly agaric only rarely reveals its enthogenic effects. The fly agaric is most certainly not the drug of the berserkers. The only psychoactive that is able to produce real aggression, raving madness, and rage is alcohol. The berserker madness was also induced by a beer to which ledum palustre had been added.