A potion invented by Hua Tuo to erase the drinker's memory. He originally invented it to erase his master's pain of losing her son. It was partial failure, because it did not erase her pain, however, it erased her memory of having promised Hua Tuo to provide him money for a living. While it was still in early stage of development, the potion loses effects after the drinker urinate it. However, after it was finished, the memory gap was able to stay permanent.