By Laurie Winer  |  Published in NYTimes

Liz McDonald is in her third year of teaching a Saturday class called 420 Remedy Yoga.

Liz McDonald is in her third year of teaching a Saturday class called 420 Remedy Yoga.

Liz McDonald is in her third year of teaching a Saturday class called 420 Remedy Yoga.

Her studio, Brazilian Yoga, is in Atwater Crossing, a bohemian outpost near Glendale, Calif.

As a courtesy to her students there, some of whom might be wandering about blissfully, Ms. McDonald starts the class at 4:25.

The number 420 is code for pot smoking; the term’s origin has been traced, not surprisingly, to Marin County in the early 1970s, when a group of high schoolers met at 4:20 p.m. to commence toking.

In that era, already years after Richard Alpert changed his name to Ram Dass, drug experimentation went hand in hand with the search for being/awareness/bliss, a quest that is also a foundation of yoga and meditation.

On a recent Saturday, Ms. McDonald started her class slowly; students stretched on the floor to the sound of relaxing Indian-infused jazz, as she encouraged them to think of their yoga mats as private magic carpets.

For a while they stretched lazily, some of them gazing up at the white lanterns hanging from the rafters, as if appreciating for the first time the ethereal qualities of rice paper.

Ms. McDonald walked the floor, adjusting her students’ poses with a gentle prod.

By her side was her small dog, Prince, who every now and then imitated his mistress and touched students with his nose. An hour and a half later, the class ended with the traditional “corpse pose,” where students lie prone, palms up, and seem to be one with the ground beneath them.

Yoga practitioners who enjoy meandering thoughts and who live in Colorado and Washington State, where voters recently approved the legality of small amounts of marijuana for recreational use, may begin to see classes like Ms. McDonald’s. (Possession is still a federal offense, rendering this a complex transitional period.)

In 2003, California Senate Bill 420 cleared the drug for medical use, meaning that Ms. McDonald’s students may have doctor-issued licenses, which can easily be obtained for ailments like anxiety, sleep disorders or chronic pain. It is illegal to smoke on the Brazilian Yoga property, so students are expected to partake at home.

Human beings have been cultivating the herb for thousands of years. “At least some of the ancient sages were probably stoned out of their minds,” said Leslie Kaminoff, a Manhattan yoga teacher and author of “Yoga Anatomy.”

Though he said he does not use or teach with any kind of enhancement, Mr. Kaminoff noted that “drugs can be a tool, and every tool has a positive and a negative aspect to it.”

Yet, with the exception of fringe groups composed of people like Ms. McDonald, most yoga teachers will tell you that drugs have no place in the practice. “One of the things yoga teaches, even in something as simple as holding an uncomfortable pose, is how to tolerate reality,” said Nancy Romano, a private instructor in Los Angeles. “So any substance that fiddles with our ability to be with what’s really happening would not be helpful in a yoga practice.”

As a child, Ms. McDonald, 34, had what was considered severe scoliosis; now, thanks to her yoga practice, she is able to twist herself like a pretzel and stand on one leg — the “bird of paradise” pose.

She is well aware that many in the official yoga industry would disapprove of her 420 class and doesn’t care. “I find it to be a valuable tool in teaching,” she said.

“Disbelief is my biggest obstacle. People don’t believe that they can feel their heart beat or that they can send breath into their lower appendages. A little pot relaxes them into comprehending. And if you want to just lie down in my class, that’s O.K., too.”

William Sands, dean of the College of Maharishi Vedic Science at Maharishi University of Management in Fairfield, Iowa, represents the stringent opposition. He has just finished writing a book on Maharishi Mahesh Yogi, who mentored the Beatles and introduced the West to transcendental meditation.

Dr. Sands said that “marijuana inhibits the ability to experience yoga — the inner self — and is therefore incompatible with the practice of transcendental meditation.” To Dr. Sands, yoga is the full package: a physical and mental discipline.

Others make a distinction between the kind of discipline required for yoga and for meditation.

Ms. McDonald said she understands why certain yogis disapprove of pairing the practice with pot. “Some devotees have literally dedicated their lives to yoga,” she said, “and as a result they tend to see it as an ideal, beyond human flaws, capable of our salvation. I think that perfection is found by authentically being in the present moment, rather than as an outcome of enlightenment. So I’m not afraid to admit I’m not perfect and come out of the closet on these issues.”

Dee Dussault of San Francisco is another rare instructor who advertises what she teaches, in her case Ganja Yoga.

Ms. Dussault traces the division between what she calls tantric yoga and straight yoga to the Buddha, who advocated purity.

“Tantric yoga says you use whatever tools are available to get to a place of transcendence,” she said, adding the caveat that marijuana must be used “mindfully.”

Yoga and herb intake have been linked since ancient times. The yoga sutras, written in Sanskrit before the time of Christ, are considered the practice’s foundational text.

The sutras list herbs as one of five methods to lift the veil of ignorance, or the barrier between the conscious and the unconscious. Dr. Sands, though, expressed skepticism, saying that the “herbs” in question could be as uncontroversial as cardamom. “People who interpret the sutras’ use of ‘herbs’ as marijuana,” he said, “are looking for a rationale.”

But Mark Haskell Smith, the novelist and author of the nonfiction “Heart of Dankness: Underground Botanists, Outlaw Farmers, and the Race for the Cannabis Cup ,” is pretty sure that the sutras do not refer to cardamom.

A yoga practitioner for 20 years, Mr. Smith said he occasionally uses pot when he practices. When he does, he said, he finds that “I go more deeply into the asanas,” or poses.

“Part of the point of yoga is to relax the body,” he said. “And marijuana helps a lot of people to do that.”