Wormwood Side Effects and Warnings

Safety Issues

There are many unsolved questions about the toxicity of wormwood. When absinthe was popular in the late nineteenth and early twentieth centuries, a mental disorder known as “absinthism”—involving hallucinations, tremors, vertigo, sleeplessness, and seizures—was associated with it. Wormwood contains thujone, a substance thought to be toxic to nerves when taken at high doses, and thujone has been proposed as a factor contributing to absinthism. However, the symptoms of absinthism are also consistent with mere chronic overuse of alcohol, and absinthe does not appear to contain sufficient thujone to cause harm. ¹ Furthermore, animal studies have generally failed to find significant toxicity with wormwood even at relatively high doses. ² Despite the absence of firm evidence, wormwood is still considered a potentially toxic herb, especially if taken over the long term. Wormwood essential oil contains thujone at much higher levels than those found in absinthe, and should be avoided. Wormwood should not be used by young children, pregnant or nursing women, or people with severe liver or kidney disease.