An endless range of bizarre concoctions have been devised with the aim of restoring failing sexual powers. Sometimes, as we have seen, plants were used because of their physical resemblance to the human genital organs. Drugs have always been popular. Perhaps the most bizarre types of aphrodisiac are those involving an element of cannibalism. We all know of the use of parts of non-human animals to increase human potency (a Chinese Emperor, for example, kept a herd of deer so he could drink their blood to increase his virile powers), but often it was thought desirable also to consume parts of men and women for this purpose. Menstrual blood, placenta, and genitals have all been devoured to increase sexual prowess semen was also popular. ("The semen of virile young men should be mixed with the excrement of hawks or eagles and taken in pellet form.") Chinese eunuchs, seeking regeneration of their lost sexual organs, would hopefully eat the warm brains of newly decapitated criminals.