Throughout history, aphrodisiacs, substances to enhance sexual pleasure and increase sexual desire, have been the subject of much discussion and interest.

Foods that have been associated with aphrodisiac effects, such as oysters, have not been proven by medical science to have an actual clinical effect on sexual desire.

However, the placebo effect may take over when the consumer of certain foods believes they are effective.

Certain drugs are considered to be aphrodisiacs. Some of these drugs are Yohimbine, Bremelanotide and a chemical called phenylethylamine or PEA.

Yohimbine is a weak MAO inhibitor and may be effective as it increases genital blood flow and also sexual sensitivity for some people.

Bremelanotide is a new drug and so far it appears to be a real aphrodisiac. It is presently being tested in clinical trials for treatment of sexual arousal disorder and erectile dysfunction. Bremelanotide increases sexual desire in both men and women.

PEA, or phenylethylamine, is a chemical present in chocolate. It is the subject of controversy and debate over whether it can be classified as an aphrodisiac.

Chocolate is said to act as a sedative that lowers inhibitions and a stimulant that increases craving for physical contact. Alcohol, often touted as increasing sexual desire, is not considered an aphrodisiac in the clinical sense.

Alcohol, however, can reduce inhibitions therefore increasing sexual desire by it's psychological effect.

The popular recent drugs used to treat erectile dysfunction, Viagra and Levitra, cannot be classified as aphrodisiacs, as they have no effect on mood. They are effective physically but not psychologically.

Perfumes made with natural substances such as almonds and vanilla are said to act as pheromones through the sense of smell.

In the United Kingdom, the Intrinsa Testosterone patch has been approved for women with a low libido. Testosterone is recognized as a substance that can boost a women's sexual drive.

Research done has shown that women respond with more sexual thoughts and engage in sex more often with the use of Intrinsa. It is not approved by the FDA in the U.S. because of increased risk of cancer and uncertainty over longterm safety of usage.

Certain rumors and myths abound about particular aphrodisiac combinations and foods. Mixing Coke and aspirin, for example, is more likely to cause a stomach ache than anything. Any rumor about it as an aphrodisiac is false.

Another commonly believed aphrodisiac is the consumption of shark fin soup. This food shows no scientific proof for increasing libido. The psychology, or sympathetic magic, behind this practice is that a human is trying to harness the ferocity and strength of the shark.

Few subjects have been so interwoven with folklore and controversy as the effectiveness of aphrodisiacs. The psychosocial complexity of human sexuality, spiritual beliefs and social norms all impact this aspect of human behavior.