Before viagra
In the animal kingdom, there are always a number of males who find sexual intercourse difficult. Humans are no different in this respect. From the beginning of recorded history, there are reports of men with erectile dysfunction (and descriptions of the social difficulties this caused). Because men have been considered the dominant gender, loss of potency has been seen as a loss of manhood. Such men have been the object of pity and derision. For this reason, there has always been a market for “cures”. Almost without exception, these were sold by fraudsters. The only reason for some level of success was the placebo effect, i.e. if a user believes strongly enough in the power of the medication, it will have an effect. In modern clinical trials, an average of about one-third of all participants using the placebo report beneficial results from the chemically inactive pills and creams. Because of this, the majority of “experts” believed erectile dysfunction was a psychological problem. Men who used an aphrodisiac or a fake medication reported a resumption of sexual activity.

The first steps to a treatment
Ignoring the early remedies and the use of expensive implants, e.g. of goat glands in the 1920s, the psychological breakthrough came in 1983 when Dr. Giles Brindley gave a practical demonstration to a surprised gathering of urologists in Las Vegas. In a conference to discuss the treatment of impotence, he injected himself with phentolamine, a non-specific vasodilator, and publicly displayed the resulting erection. This is a drug designed to relieve sudden and dangerously high levels of blood pressure by triggering a general dilation of blood vessels throughout the body. But once the principle was demonstrated, research scientists were on the look-out for a specific remedy for impotence.

The development of viagra
The problem with phentolamine was that the erection was uncontrolled and involuntary, i.e. it did not start and end in response to sexual stimulation. It was also inconvenient for men to have to inject the drug into their penis. A research team working on a treatment for angina, an early warning of heart disease, noted that men using the drug in the trials reported having erections. The rest is history. By accident, the chemists had discovered an oral medication that is specific to the blood vessels in the penis. More importantly, it was tied into the chemical messenger service run from the brain. Thus, the erections came as a result of sexual stimulation and not because of the drug. Unlike phentolamine, the erection also conveniently ended when sexual activity was over.