Recent research indicates that your saliva contains a chemical called opiorphin, which is six times more effective than dangerous narcotics such as morphine yet lacks the addictive and psychological side effects.When the researchers subjected test rats to a painful stimulus, 1mg of opiorphin per kg of body weight achieved the same painkilling effect as 3mg of morphine per kg of body weight.
The substance was so successful at blocking pain that, in a test involving a platform of upended pins, the rats needed six times as much morphine as opiorphin to render them oblivious to the pain of standing on the needle points
Catherine Rougeot at the Pasteur Institute in Paris, France, who led the research, says “Its pain-suppressive effect is like that of morphine. But we have to test its side effects as it is not a pure painkiller, as It may also be an anti-depressive molecule.”

Rougeot and colleagues discovered that opiorphin works in nerve cells of the spine by stopping the usual destruction of natural pain-killing opiates there, called enkephalins. Opiorphin is such a simple molecule that it should be possible to synthesise it and produce large quantities without having to isolate it from saliva, Rougeot explains. Alternatively, it might be possible to find drugs which trigger patients’ bodies to produce more of the molecule themselves.