On April 29, 1997, the supermarket tabloid the National Examiner ran this headline on its cover: "Miracle Pain Cure: Deadly Snail Venom." The garbled story within contained a kernel of truth. Doctors in fact were injecting a drug derived from the venom of a marine snail into patients suffering from the worst kinds of pain imaginable.

One of the researchers responsible for this unlikely drug, neuroscientist George Miljanich, sits beneath a framed copy of the tabloid cover, which shares wall space above his South San Francisco, CA, desk with more staid covers from the journals Molecular and Cellular Neuroscience and the Journal of Neurocytology, among others. Miljanich works for Dublin, Ireland-based Elan Pharmaceuticals, and his snail-derived drug is called ziconotide.

For the last 50 million years, predatory snails in the Pacific Ocean have been stabbing passing fish and killing them with their venom. In tiny amounts, though, one component of the venom actually blocks the pain in desperately sick and injured people-at least among the nearly 2,000 who have tried it to date. "Ziconotide is about a thousand times more potent than morphine," Miljanich says. "Upwards of a third of these patients experience significant improvement in their quality of life."

Ziconotide is not yet approved by the U.S. Food and Drug Administration, and because it can cause severe side effects, its future remains uncertain. But its ultimate fate in the marketplace is, in a way, beside the point. Because of its effectiveness in halting pain, ziconotide has spawned a new generation of drugs deliberately designed to block the electrical impulses that generate pain signals, without affecting other systems in the human body.