Recent news stories have reported that marijuana sparks the sex drive by raising testosterone levels, tranquilizers prolong male "staying power," substances isolated from human sweat enhance sexual desire, room deodorants intensify orgasms, neurotransmitter boosters extend arousal for hours and antidepressants "drive" women to new sexual highs.
In a society that asks medical science to cure everything from plagues to pimples and wrinkles, the search for better sex through chemistry is hardly surprising.
But are the stories true? Do genuine aphrodisiacs exist? The good news is that the answer is a qualified "maybe."
"If you mean a substance that makes the object of your affection fall in a swoon into your arms, the answer is no," said Dr. John Money, a medical psychologist at Johns Hopkins University School of Medicine who pioneered research in sexuality and drug use. But "if you mean some things in small amounts that enhance the intensity of sexual pleasure sometimes in some circumstances for some individuals--perhaps."
The bad news is that for healthy men and women, shopping in Aphrodite's drugstore for new sexual thrills carries serious risks--emotionally and physically.
To begin with, evidence of aphrodisiac effects lacks scientific credibility. It is largely, if not wholly, anecdotal, inferential, spotty and unconfirmed.
A few years ago, for example, experiments by Gian Luigi Jessa, a pharmacologist in Sardinia, created something of a sensation with reports that a diet free of tryptophan, a nutrient found in milk, cheese and other dairy products, caused lab animals to become oversexed, apparently by depleting them of serotonin, a brain chemical important in mental activity.
But no similar results have been reported in human or additional animal studies. And it's not even clear that such experiments have been done.
There was another surge of interest caused by a report this year in the Canadian Journal of Psychiatry that three patients taking clomipramine, an antidepressant, experienced "irresistible sexual urges" and instant orgasms. And the American Journal of Psychiatry reported increased sexual desire in six of 13 patients on trazodone, another antidepressant. Less well publicized are the more numerous reports of suppressed sexual responses from these drugs.
Although research in aphrodisiacs is staffed by some notable psychiatrists, psychologists, pharmacologists, endocrinologists, chemists and neurologists, the fact is that precious few controlled clinical trials have ever been done, even with drugs that offer good leads. And they may never be done.
The scientific establishment generally condemns or ignores research on healthy people that suggests positive effects of a chemical on sexual performance. The reasons are partly ethical--giving drugs to healthy people carries risks--and partly cultural--there is great unease with the idea of encouraging sexual prowess.
"As a result," Money said, "practically nothing is known about dosages, tolerance or the influence of age or gender or personality on the effects of any aphrodisiac." And given the Puritan attitude toward sex in much of society, he added, "there is serious question about whether we'll ever be allowed to find out."
What credible scientific evidence there is on the influence of drugs and hormones on sexual behavior has been drawn from reported side effects of necessary drug therapy or from studies among people who are unhappy or sick, physically or emotionally--including drug addicts, prostitutes, transsexuals, the sexually disordered and people born with abnormal sex hormone and gender characteristics.
European scientists have discovered that a few women taking bromocriptine mesylate, a fertility drug that acts on a gland at the base of the brain, report higher-than-ever interest in sex. The drug also reportedly increased sexual interest in a few men with abnormal levels of prolactin, a fertility hormone. But the drug has dangerous side effects and is at best prescribed only for women with pituitary tumors that cause infertility.
L-Dopa, a chemical building block of dopamine used to treat Parkinson's disease, was incidentally found to restore sexual interest in about 1% of the victims of this palsy. A few scientists then tried it on non-Parkinson's individuals as an aphrodisiac. But inconsistent results and side effects stopped the studies. One finding was that the drug seemed to have aphrodisiac effects only on those who needed it least.
Drugs commonly used to treat high blood pressure and depression have been reported in a few instances to arouse or sustain sexual pleasure.
PCPA, a drug that inhibits serotonin and is used to treat migraines, has increased sexual arousal in a few patients.