From
Newsweek:
Alleged Arizona shooter Jared Loughner used salvia, the hallucinogenic drug, according to a high-school friend of his. Obviously, Loughner was troubled. But did salvia have anything to do with it?
Currently, there’s very little scientific information about the drug’s effects.
Salvia is still legal in a majority of states, and millions of Americans have used the drug without incident.
What little research that has been done shows that all strains of Salvia divinorum, a plant grown for centuries in Mexico, produces a chemical called Salvionon A. This chemical affects the kappa opioid receptor, a part of the brain that’s in large part responsible for our perceptions of reality.
In an unmodified state, salvia—whether it’s smoked, chewed, or swallowed in extract form—produces an intense high, lasting less than half an hour. Typically, those who use salvia are not able to do much, says Johnson. The limited intoxication period of the drug, combined with its impairing effects on mobility, make it unlikely that Loughner used it at the time of the shooting.