Getting High on Salvia, for Science

The Salvia divinorum plant. Phyzome via Wikimedia Commons CC3.0

Some people literally forgot which way was up, or didn't know if they owned their bodies anymore. Others felt their internal organs being pulled in directions across all three planes, and through extra dimensions they hadn't known existed. And a few could "feel" objects by looking at them.

All these reports come from people smoking an herb in the sage family called Salvia divinorum, commonly referred to as salvia. This plant has been used in religious ceremonies by the Mazatec people of Mexico for centuries. They associate it with the Virgin Mary, and believe ingesting salvia enables them to speak with her.

For the past few decades, the plant has also enjoyed popularity in the U.S. for its psychoactive effects, and there has been a digital flood of videos of people smoking it on YouTube. The reactions are varied, but often involve somebody spacing out, giggling tremendously, becoming incapacitated, stumbling about, or some combination of the above.

Peter Addy, a researcher who is now at Yale University, decided to conduct the first large study to describe the subjective effects of smoking salvia. While still at the Institute of Transpersonal Psychology in Palo Alto, California, Addy got 30 participants to smoke salvia in a relaxed setting, in a lab, while seated next to him. (A medic was standing by outside, but was never needed.) Addy sat next to each person while they smoked a pre-prepared sample of the herb, and after the 10- to 15-minute trip, talked with them about their experiences.

The first and most pronounced effect is the suddenness of the high. "When you smoke salvia it's like flipping a switch—everything is normal, and then immediately everything is different," Addy says. It's also particularly intense, and unique: it evades comparison to any other kind of drug, he adds.

In contrast to the effects of other psychoactive substances, the experience of salvia is also quite hard to pin down or characterize simply, with many people having quite different trips, he says.

But one common thread that ran through most of the trips was that salvia changes a person's "interoception"—the body's sense of its own physiological conditions. And it also seemed to alter self-awareness and sense of reality.

"I got completely in it and completely lost my orientation of where I was," one participant said. Nearly 60 percent reported similar feelings of disorientation, with some forgetting where they were in space. A few people completely forgot that they had smoked salvia and couldn't remember why they were in the lab in the first place, Addy says.

Salvia changed the way people perceived their own bodies. "I was blended in with the air around me," wrote one woman. "I couldn't tell if I was part of the carpet, or you're part of the chair," chimed in another man. It also affected people's sense of what was real.

Nine of the 30 said that they became completely unaware of their surroundings, undergoing an experience that was completely removed from the "reality" of the laboratory setting. "I didn't have a sense of being in a position to observe myself," wrote one participant. A total of 11 participants "sensed other people or beings" during their experiences. "I got the impression that other people could hear me and they were around," one wrote.

A number of participants reported emotional changes: one-third said it made them happy, and four people described being scared. Only two people had what Addy described as a "bad trip," meaning a difficult experience marked with anxiety. But once the effects wore off, they were fine, he says. In both cases, these individuals said that the fear arose primarily from the fact that they had no control over the experience. Another four who didn't have a tough time also felt helpless to direct the trip, but "rode it out" without much trouble.

"When you smoke salvia you're having an experience whether you want to or not," Addy says. Most participants said that the trip was pretty weird, but ultimately neutral—not especially good or bad.

Salvia is one of the most potent hallucinogens in nature, Addy says, and has a peculiar mode of action, acting on kappa opioid receptors. These neuronal receptors are thought to be involved in interoception, pain sensing, mood and consciousness. Unlike many hallucinogens, salvia does not appear to affect levels of the neurotransmitter serotonin.

Salvia might also have real potential to treat addiction, studies suggest, since in animals it appears to reduce cravings for substances like cocaine. In effect, it acts in the brain quite opposite to the way that most opiates do, Addy says.

Addy adds that salvia is powerful, but not particularly dangerous if treated with care; and due to its unique properties, it could teach us new things about the brain. Though the drug remains legal at the federal level, it is currently outlawed in a number of states, and others have legislation in the works to ban its sale. From a scientific standpoint, says Addy, this is not a positive trend.

"Outlawing a substance can reduce street use, but can also reduce useful legitimate medical research, which we need to do," he says.