Smoking or chewing the leaves of the plant sends the user on a trip that according to accounts posted on various sites can be even more intense than the LSD experience, but unlike an LSD trip, which can last six hours or more, the Mexican herb's effects usually last less than an hour, with a peak of only 20 minutes or less.
One woman who has experimented with the herb told ABCNEWS that she lost touch with her surroundings for only a few minutes, but during the experience it seemed much longer, and she found it difficult to describe everything she saw, heard and felt.
"At first I was able to tell myself, 'This is the drug,'" she said. "Then it didn't seem to matter so much what it was that was doing it, I just let it all come. I think there were moments when I was scared to death, but something kept comforting me."
The greatest danger, according to Siebert's article, comes when too much of the active ingredient gets into the user's system too quickly.
Dr. John Halpern, a psychiatrist with McLean Hospital, a teaching hospital affiliated with Harvard University, said there are other dangers with salvia divinorum, but they are dangers associated with other hallucinogens and with alcohol when they are used by people in their late teens and early 20s, when the brain is still maturing. These substances can aggravate tendencies towards schizophrenia, said Halpern, who has received a career development award from the National Institute on Drug Abuse.
The enthusiasm over LSD included hopes that the drug could be a valuable tool for psychotherapy, and similar claims are made in some of the literature about salvia divinorum, but the caution and detailed recommendations regarding dosage and preparing the proper atmosphere are a marked difference from the era of "acid tests."
"If you choose to pursue a relationship with this plant please treat it with respect and care," Siebert's article says. "Perhaps if people can use the plant safely and responsibly it will be able to grow and thrive freely into the future."
Perhaps the biggest question about the drug is how it works.
"Nobody has a clue," said Purdue University professor of medicinal chemistry and molecular pharmacology David Nichols, who has studied the effects of hallucinogens on the brain for 20 years. Nichols is among the scientists who has given information about the drug to the DEA.
He said attempts to discover which part of the brain the drug works on have thus far been unsuccessful. When tests involving the most common brain receptors were performed, the active ingredient in the herb, Salvinorum A, did not seem to bind to any of them.
When asked about potential dangers, he said thus far none have been identified, other than the potential for an unpleasant experience with the herb, which he said has more of a "disorienting" effect than other hallucinogens.
"We haven't really heard of any adverse reactions," he said. "Like LSD, when the dose is so small, unless it's a toxin it really can't damage most of your organ systems."
Dr. Edward Boyer, an assistant professor of emergency medicine and the director of the toxicology fellowship training program at the University of Massachusetts, said that over the last three years he has seen no cases of people suffering any toxic effect from salvia statewide in Massachusetts.