Beyond their collective exoticism, the only thing the above have in common is that they don't work. Named for Aphrodite, the Greek goddess of sex and beauty, an aphrodisiac is just about anything that awakens or increases sexual desire--be it your own, or the object of your desire's. In reality, however, most aphrodisiacs are folklore at best and hazardous to your health at worst. As the Food and Drug Administration has declared: "There is no scientific proof that any over-the-counter aphrodisiacs work to treat sexual dysfunction."

But there is still some hope for those seeking a libido boost. The herbal supplement Ginkgo Biloba is being studied by the Office of Dietary Supplements, a subsidiary of the National Institute of Health, as a treatment for erectile dysfunction. The FDA has called animal studies of yohimbine "encouraging." Derived from the bark of an African tree, yohimbe has been used as a sexual stimulant for centuries. But the FDA notes that animal studies can't be used to prove effectiveness in humans.

Even when aphrodisiacs do show promise, they don't always work for everybody. Sexual desire is rooted in the mind more than the genitals. One person's fantasy could be another's turn-off. "We're all unique individuals, and we all respond differently to different things," says Dr. Beverly Whipple, a professor emerita at Rutgers University and author of, most recently, The Science of Orgasm.

At the root of human sexual desire is the "core erotic personality"--a.k.a. "sexual template"--which, in a nutshell, is whatever gets you off. "Everyone has in their mind an image of someone or thing they find sexually desirous," explains Dr. William Granzig, dean of clinical sexology at Maimonides University in North Miami Beach and president of the American Board of Sexology.

That image might be a person of specific age, race or hair color, or it might be every person. It could be a fondness for a particular style of dress, objects such as women's shoes or fur-lined handcuffs, or behavior such as cross-dressing or exhibitionism. Whatever it is in particular, the sexual template is believed to develop early on during a childhood erotic experience--perhaps as early as age three or four--and it sticks with you for life.

The difficulty of maintaining sexual desire over the long term, of course, is that if your partner falls outside of your sexual template--or you fall outside theirs--sooner or later one of you could lose interest. "Many people whose template is not, say, age-specific, can have great sex throughout their lives," notes Granzig. "But if you're only attracted to 20-year-olds, once your partner hits 30, your desire will decrease. Unless, of course, you can figure out some ways to spice things up."

Spicing things up is where sex gets complicated, because men and women sometimes have wildly divergent desires. For men, a sexy photo is often enough to get blood flowing in the right direction. For women, pornography can be a major turn-off. Orgasms are also less central to women, who sometimes need full body stimulation, not to mention mental seduction, in order to achieve climax. "There are just so many variables that go beyond the physical in sex for women," says Dr. Janice Epp, a clinical sexologist at the Institute for Advanced Study of Human Sexuality in San Francisco.

There are also a host of external nuisances that weigh heavily upon sexual desire--and that may dampen the mood. Studies routinely rank American culture as one of the most sexually repressed in the world thanks to its forbidding Judeo-Christian origins, high incidence of sexual problems and dysfunction, and a lingering Puritan discomfort with the very topic of sex.

And while Europeans take mandatory month-long vacations, Americans routinely work 60-hour weeks, and stretch their ten vacation days over the entire year. With the demands of our modern day technological society, it's little wonder the search for aphrodisiacs continues. "I see a lot of highly evolved, highly skilled people who are losing desire because they have such an overriding focus on their profession," says Epp, who works in Silicon Valley. "For them, the temptation to believe that there's a magic pill that will make them desirous of sex again is very strong."

Inspired by the phenomenal success of Viagra, which rang up over $1.6 billion in sales for Pfizer in 2005, it's perhaps not surprising that there has been a recent push to find more pharmaceutical remedies for flagging sexual desire. It's a focus that throws many in the sex field into apoplexy. "The idea that you can just give someone a pill, and they'll be interested in sex is like putting a band-aid on a tumor," says Epp.

In the end, the only truly effective aphrodisiac seems to be that's been working for humans all along. "Your biggest sex organ is the one between your ears," says Dr. Granzig. "What is desire, after all, other than the hope that you can fulfill your sexual fantasies? And that's all in your mind."