Rudolf Steiner hypothesised that mistletoe could cure cancer, on the basis of the observation that the plant was a parasite which eventually killed its host, a process which he claimed paralleled the progression of cancer.[1] Steiner believed the plant's medical potential was influenced by the position of the sun, moon and planets and that it therefore was important to harvest the plant at the right time.[28] Some mistletoe preparations are ultra-diluted; others are made from fermented mistletoe.[2] The most commonly used trade names for mistletoe drugs are Iscador and Helixor.[3]