An aphrodisiac is an agent which causes the arousal of sexual desire. The name comes from the Greek goddess of love Aphrodite. Desire can be stimulated by a variety of events or situations (see sexual arousal), but this article focuses on foods and drugs which are known to have an aphrodisiac effect.

Newly introduced exotic fruits or vegetables often acquire such a reputation, at least until they become more familiar.

• Eringoes (the Sea holly, Eryngium maritimum)
• Oysters
• Potatoes
• Spanish fly (Cantharidin)
• Tomatoes

Some aphrodisiacs appear to gain their reputation from a process of similarity, hence the trade in rhinoceros horn that is endangering this animal. (See Carl Hiaasen's 1997 novel Sick Puppy.)

Others may gain their reputation from the apparent virility or aggressiveness of the animal source - such as tiger bones - also endangering the species.

There is some debate in lay circles as to whether a chemical called phenylethylamine present in chocolate is an aphrodisiac. But this compound is quickly degraded by the enzyme MAO so that significant concentrations cannot be reached in the brain.

Medical science has not substantiated claims that any particular food increases sexual desire or performance. However, a new drug called PT-141 seems to be the first real aphrodisiac. It stimulates sexual desire in men as well as women and is currently in clinical trials for the treatment of sexual arousal disorder and erectile dysfunction.

Psychoactive substances like alcohol and cannabis are not aphrodisiacs in the strict sense of the definition above, but they can be used to increase sexual pleasure. Alcohol reduces inhibitions and in excessive quantities degrades cognitive functions, thus lowering the usual barriers to sexual abandon. Cannabis enhances the sense of pleasure, and increases the level of absorption in the present moment, thus intensifying both desire and sensation.

Drugs like yohimbine or Viagra are not aphrodisiacs because they do not have any mood effects.