Aphrodisiacs are substances that arouse sexual desire or enhance sexual performance. For many centuries there has been a search for substances that could increase a person's sexual powers or desire.

Among the many substances that have been claimed to have such an effect are oysters, ginseng root, powdered rhinoceros horn, animal testicles, and turtles' eggs. There is no evidence that an actual aphrodisiac response occurs with these or any other substances.

Just how certain foods or other substances come to be seen as aphrodisiacs is typically a matter of folklore rather than fact. In some cases the newness or rarity of a food or chemical invite people to endow it with magical powers of a sexual nature.

In other instances, sexual strength is assumed to come from eating foods resembling a sex organ, such as bananas and oysters because of their vague resemblance to the penis and testicles. While the notion that the shape of an unrelated object should qualify it as an aphrodisiac seems absurd to most, people continue to view some foods as aphrodisiacs.

Are Oysters Really an Aphrodisiac?
In the case of oysters, probably the classic among the alleged aphrodisiacs, chemical analysis shows that it consists of water, protein and carbohydrates, plus small amounts of fat, sugar and minerals. None of these components is in any way known to affect sex drive or performance. The psychological impact of believing that oysters, raw bull's testicles ("prairie oysters", as they are called), clams, celery, or tomatoes are aphrodisiacs is sometimes strong enough to produce, at least temporarily, greater sexual desire or performance. The experience of enhanced arousal or performance is then falsely attributed to the wonder food, and this discovery is passed on to the next person wishing to experience new heights of sexual experience.

Eating certain foods to increase sexual power, while ineffective, is generally harmless. Other supposed aphrodisiacs, however, are not so innocuous. Spanish fly (cantharides) is one such substance. It is made from a beetle found in southern Europe. The insects are dried and heated until they disintegrate into a fine powder.

When taken internally, the substance causes irritation of the bladder and urethra, accompanied by a swelling of associated blood vessels, all of which produce a certain stimulation of the genitals that is interpreted by some men as a sign of lust. The drug can cause an erection, but usually without an increase in sexual desire. Furthermore, if taken in excessive amounts, it can cause violent illness and even death.

Alcohol and Sex
Alcohol is another substance that most people believe increases their sexual responsiveness. This is partly because alcohol has a disinhibiting effect—it lowers the sexual inhibitions a person may ordinarily have, thus allowing sexual desire to emerge. Alcohol's reputation as an aphrodisiac also stems from advertising and cultural myths.