Medieval alchemists, and more recently Harry Potter, spent time seeking the philosopher's stone, thought to be the elixir that bestowed long life and perhaps even immortality.
Fifty years ago this month, a genuine philosopher's stone was discovered — only it was a small, white tablet called Enovid, the first oral contraceptive.
For the first time in history, women could choose if and when to have a child with relative ease. No uncertain rhythm method, no embarrassing interruption of lovemaking to put on a condom. Just a highly effective, easy-to- use method.
Yet from the get-go the pill was intensely controversial. The early oral contraceptives had much higher doses of hormones than are used today, and there were deaths from blood clotting. The dangers hit the headlines.
Ultimately, the real test of whether any drug is safe to use for long intervals is to follow users for long intervals.
In 1968, Britain decided to study 23,000 women using the pill and to compare them with 23,000 women not using the pill. In March, the British Medical Journal published a stunning 39-year follow-up of these same women, with a mind-boggling cumulative total of 1.2 million years of observation.
At last we can say with unprecedented confidence that the pill is indeed a philosopher's stone, extending life by a measurable amount.
It is the only drug a doctor can prescribe that is known to prevent cancer. The pill suppresses ovulation, and in doing so, it halves the risk of developing uterine or ovarian cancer. Women who have used the pill are less likely to develop colon cancer and have fewer melanomas.
The protective effects of having taken birth-control pills persist for many years after swallowing the last tablet. Long term, even heart disease deaths are fewer.
This does not mean that the pill is safe for everyone, and certainly women who smoke and are over age 35 should not use the method.
The pill and other methods of contraception also have important non-contraceptive benefits. Babies born too close together have an increased infant mortality rate. If all pregnancies in the world were spaced three years apart, there would be 2 million fewer infant deaths each year. About half of the decline in maternal deaths in the West over the last century is because women are having fewer children.
So why does the pill continue to have a bad image? Contraception challenges patriarchal traditions. Japan took 40 years to OK the pill but only six months to approve Viagra.
John Rock, the obstetrician who conducted the first trials of the pill in Boston and a devout Catholic, argued that the pill was natural because it imitated pregnancy and breastfeeding.
Most people expected the Vatican to bless the new method as licit for Catholics. Instead, in 1968, Pope Paul VI condemned it. Rock and millions of Catholics stopped going to Mass, but popes up to and including Pope Benedict XVI have continued to tell Catholic women not to use birth-control pills.
Finally, the pill is misunderstood because it has remained a prescription drug — not for any scientific or safety reason but simply for pharmaceutical companies' profit. Not until the pill is on sale next to Tylenol will women believe how safe it really is.
The pill can save the lives of infants and prevent maternal deaths. It reduces the burden of abortion. It is prerequisite for the autonomy of women, and it enables couples to express their love in physical ways without the fear of unintended pregnancy.
The pill truly is a philosopher's stone, and in a very real way is less unnatural in the modern world than doing nothing.
Potts, a British obstetrician, is a professor at the University of California at Berkeley and has published extensively on contraception.
LOS ANGELES TIMES