Long before CBD had become a trendy wellness elixir found in juice and moisturizer and ice cream and dog treats; before corporate chains like Walgreens and Sephora had decided to sell it; and way before Kim Kardashian West had thrown a CBD-themed baby shower, a ragtag crew of activists, doctors, writers and marijuana farmers met up on an early winter evening in 2011. They sat in a circle at a house in the hills a few hours north of San Francisco — where wine country becomes weed country — to discuss the therapeutic potential of CBD, and how to get people to take it seriously.

Several studies in rodents and in cell cultures had suggested that CBD, a nonintoxicating compound from the cannabis plant more formally known as cannabidiol, could protect the nervous system, modulate blood flow, slow the growth of cancer cells and provide relief from seizures, pain, anxiety and inflammation.

“We were talking about, ‘What can we do with this?’ ” recalled Samantha Miller, who hosted the event at her split-level house, wedged between redwoods and a creek below. A headstrong biochemist, she had been growing marijuana since the age of 14 and had just quit a six-figure job to start her own cannabis testing lab.

After two years of tracking down high-CBD pot plants and building momentum, the group began to devise ways to persuade more farmers to grow strains with CBD — which had largely been bred out of American pot since it doesn’t get you high. In addition to convincing marijuana dispensaries to widely carry CBD, they wanted to educate the public about its promising benefits.

As the group of ten or so brainstormed, a balloon of vaporized pot was passed in one direction and a bong in the other.

“There was a strong sense that this was really going to be something, if when people use these strains they have any kind of experience like the mice did in the laboratories,” said Martin Lee, a writer who at the time had been finishing a book about the social history of marijuana for Simon & Schuster.

Near him was Stacey Kerr, a physician with flowing silver hair who served as treasurer of the Society of Cannabis Clinicians, as well as Wade Laughter, a soft-spoken man in glasses who had started cultivating pot for his glaucoma in the mid-90s. Mr. Laughter and Lawrence Ringo, an old-school hippie grower, were some of the first Americans to intentionally cultivate plants higher in CBD than in THC — the compound that does get you high. Both pledged to keep their strains available for other growers at cheap prices. (Mr. Ringo said he would sell his seeds for as little as $5.)

Finally, there was Fred Gardner, a writer who had recruited almost all of these people to the CBD cause. A Harvard-educated former antiwar activist, now 78, Mr. Gardner had been writing about CBD since the late 1990s for publications like Synapse, the U.C. San Francisco weekly. For years, he’d been determined to connect the nascent CBD research he heard about at symposiums abroad with the medical marijuana movement in California. And with this group, finally, it seemed to be coming together.

Ms. Miller spent the months after this meeting leading hundreds of CBD seminars for farmers; Dr. Kerr began informal patient surveys to track how CBD made people feel; and as he finished his book, Mr. Lee often traveled around with Mr. Laughter and Mr. Ringo’s high-CBD plants and seeds, spreading the gospel at pot shops across the West.

“I was aware that this was a pretty special moment,” Dr. Kerr told me, talking about the night at Ms. Miller’s. “That it was the beginning of something big, and we were there to see it.”

At the time of Samantha Miller’s summit in 2011, THC was the sole chemical “face” of the plant. Cannabis containing significant amounts of CBD was still rare. Police raids and federal prosecution of medical marijuana businesses were still common. And because CBD doesn’t get you high, it was easy to miss; hardly anyone outside of pharmaceutical companies and academia had heard of it.

In the nine years since that night in the woods, one of the group’s biggest goals has clearly been accomplished: People know about CBD.

Jennifer Aniston loves beauty products made with it. The N.F.L. star Rob Gronkowski sells it. Mike Tyson offers a cannabidiol-infused water called DWiiNK. On Instagram, #cbd is four times as common as #resist. Last year, the investment bank Cowen estimated that the U.S. CBD industry will be worth $16 billion by 2025. And e-commerce sales of CBD have grown this year amid the coronavirus pandemic.

But the CBD landscape of 2020 looks nothing like what the activists and scientists intended. That’s because the federal government’s insistence that cannabis has no legitimate use as a medicine created two enormous problems: the proliferation of fake CBD products and the nonsensical separation of CBD from THC.

Clinical studies have shown that CBD is most effective when paired with at least some THC, even if it is not enough to cause a high. However, the United States considers cannabis with THC to be a Schedule 1 drug — which puts it in the same category as heroin, indicating a high potential for abuse and no accepted medical use. This makes further research very difficult to do, and causes sick people in many states to be treated as criminals.

Cannabis that is high in CBD but extremely low in THC was made legal at the end of 2018. But finding an easy, affordable test that is able to distinguish cannabis with THC from cannabis without THC has been prohibitively difficult for farmers and crime labs alike. So federal agencies have been slow to regulate the booming industry — leading to a deluge of tinctures, smoothies and lotions that trusted tests have shown contain no CBD at all.

In the absence of oversight, the push to get more patients access to cannabis medicine — and bona fide CBD — has been co-opted by a push to make as much money as possible off the next big wellness fad. “At a certain point, it had a life of its own,” Ms. Miller told me.

Now, the CBD industry promises a miracle drug but is often selling a placebo: cannabidiol products with zero cannabidiol inside. As a result, the compound is often caricatured as snake oil, a scam, even as promising research into the full potential of CBD is starting to pick up.

The compound’s reputation is a microcosm of what it means to be in America right now: a thing that some of us consider a hoax and others praise as the solution to everything. But CBD’s rollicking journey from the international underground to cultural ubiquity proves that, as usual, the truth lies somewhere in the middle.

As marijuana use increased in the 1960s and ’70s, and the Nixon administration criminalized drugs to vilify what one aide described as “the antiwar left and black people,” the more science-minded side of the government began funding some basic cannabis research. A man named Carlton Turner helped establish the government’s Marijuana Research Project at the University of Mississippi. After that, he became President Ronald Reagan’s drug czar, helping to expand the War on Drugs.

But all the while, Mr. Turner was in touch with a Brazilian scientist named Elisaldo Carlini who had done small-scale human studies showing CBD reduced seizures: “All the early work on CBD was Carlini in Brazil,” Mr. Turner told me this past summer. “We were in communication for many years.”

For decades, Dr. Carlini’s research was not replicated, in part because so few people had access to the compound: Both the pot held at the nation’s sole government-sanctioned marijuana lab at the University of Mississippi and the illegal pot being smoked around the country had only trace CBD content. (Mr. Turner even tested several kinds of cannabis sent by a legendary pot grower, a writer for “High Times” named Mel Frank. To no avail: none of it contained much CBD.)

In those years, emissaries of California’s counterculture were often traveling the world looking for unique strains of cannabis. The most influential of these collectors was a man named David Watson. In the early 70s, Mr. Watson sold his possessions and began hitchhiking from Morocco to India, befriending local pot growers along the way.

Mr. Watson ultimately settled in Amsterdam to examine his thousands of kinds of cannabis at his own Dutch state-licensed company, HortaPharm BV. He brought in a friend, an American botanist named Robert Connell Clarke to help. When Mr. Watson and Mr. Clarke heard about the CBD research Dr. Carlini had done in Brazil, the pair identified and then bred CBD varietals. This led to a discovery.

“It attenuates the high,” Mr. Clarke told me over breakfast in Los Angeles. “That came strictly from anecdotal stoner evidence.”

Meanwhile, after multiple sclerosis patients in England became more vocal about how cannabis helped their symptoms, the country allowed a small pharmaceutical company led by a British physician named Dr. Geoffrey Guy to develop plant-derived cannabis medicines; GW Pharmaceuticals licensed varietals bred from Mr. Watson and Mr. Clarke’s collection of cannabis and got to work.

“Within a couple of years, they figured out a 1:1 combination of a high-THC chemovar and a high-CBD chemovar presented the greatest latitude of effects and prevention of side effects,” said Dr. Ethan Russo, who worked with GW Pharmaceuticals from 1998 to 2014.

As Mr. Watson and Mr. Clarke had discovered, having CBD in the mix reduced THC’s more uncomfortable effects: sedation, inebriation, a faster heart rate. And though a few outliers responded well to CBD alone, GW’s data showed that for relieving pain and inflammation, helping with sleep and alleviating seizures and spasms, most patients got the most benefit from an equal mix of CBD and THC — a drug the company called Sativex. But the research wasn’t enough. Although the drug has been approved for use in around 30 countries, the F.D.A. has yet to approve Sativex in the United States.

Mr. Gardner, the writer whose CBD advocacy eventually inspired the 2011 summit at Ms. Miller’s house, closely followed these developments. If only there were some way, he thought, for California’s outlaw weed farmers to determine whether their plants had CBD, then pot shops could offer a product similar to Sativex. Alas, Mr. Gardner wrote in 2005, that would require access to expensive testing equipment.

Enter, three years later, one of Oakland’s pioneering pot entrepreneurs, a medical marijuana impresario with pigtail braids named Steve DeAngelo. Mr. DeAngelo, who had been in contact with Mr. Gardner about the urgent need to institute better testing, agreed to help fund a cannabis analysis lab, Steep Hill, which began its operations in 2008.

Mr. Gardner came by frequently, chatting and checking in to see if Steep Hill’s founders had discovered the elusive compound. And at last, in February 2009 a dual peak on a testing graph appeared, indicating the presence of CBD.

“I remember the moment,” said David Lampach, one of the lab’s funders and co-founders. “Seeing the dual peak and realizing it was real, and running it like five times to make sure.”

By the summer of 2009, the lab had identified five strains with significant CBD and THC. Mr. Gardner was elated, and began referring to his efforts as “Project CBD” alongside other supporters, including Mr. Lee, the writer. “Right away the thought was: ‘What is the government going to say about this? How can they be against something that’s nonintoxicating?’ ” Mr. Lee said.

In June of 2010, the host of the 2011 summit, the biochemist Ms. Miller, opened her own lab, Pure Analytics. A few months later, she called Mr. Ringo, the hippie grower, to let him know a pot sample he sent in was a strain with a lot of CBD — as much as 11 percent.

“He’s in the trim room on speaker, and this big whoop goes up,” she said, remembering his staff’s excitement.

In the fall of 2010, a Project CBD website was set up where anyone could look through studies organized by disease or condition. Mr. Lee took charge of running it and it began to attract an audience. A few months later, the network of early CBD advocates met up at Ms. Miller’s house in California to coordinate their evangelism. And by the middle of 2011, word of cannabidiol had permeated the population that would become its most potent promotional engine: the chronically ill, people with cancer, with ALS, with serious disorders that weren’t responding to prescription drugs.

As stories about CBD’s power spread, demand increased and prices rose. Sick people often relied on the generosity of growers like Mr. Ringo, his son Dakota told me.

“I’d go up there and see people dying of cancer hanging out with him, and he’d be hooking them up with oil he made in his house,” the younger Mr. Ringo said. Mike Hyde, whose son was suffering from brain cancer, spent months driving around Colorado and the West Coast looking for CBD in late 2011, before connecting with Mr. Ringo at a restaurant.

“I’d never met this guy before, and he brought us literally probably $30,000 worth of oil for this CBD that no one could even get,” Mr. Hyde explained. “For free.”

CBD’s big launch into the mainstream came when the world saw evidence of what Dr. Carlini had discovered in Brazil, back in the 1970s: the compound’s ability to quell seizures. Unlike a reduction in pain, this was something any politician or camera crew could easily see. It wasn’t a stoner scam.

First, in December 2011, an epileptic child used CBD on the Discovery Channel’s “Weed Wars,” a show featuring the co-founder of the Steep Hill lab, Mr. DeAngelo. The following year, the parents of an epileptic boy in San Francisco bought CBD from a pot shop. Then, looking for a better quality product, they contacted GW Pharmaceuticals — the British company that had licensed the cannabis collection of those globe-trotting 20th century cannabis collectors, Mr. Watson and Mr. Clarke, and which conducted the research in the ’90s that spurred Mr. Gardner’s CBD advocacy. The company developed a 98 percent CBD drug for the boy and others like him.

Perhaps the most critical turning point for CBD came in August 2013, when a CNN special hosted by Dr. Sanjay Gupta profiled a 6-year-old girl in Colorado, Charlotte Figi, who used CBD to treat her epilepsy, as well as the brawny brothers who grew her CBD, the Stanleys. Hundreds of families — witnessing the power of CBD enhanced by cable news production values — moved to Colorado to gain access to the Stanleys’ CBD oil, called Charlotte’s Web. The Stanleys told me their wait-list peaked at 15,000 names. And because of public demand, the F.D.A. fast-tracked clinical trials of GW Pharmaceuticals’ 98 percent CBD drug, Epidiolex.

Suddenly, everyone wanted CBD, even though no one quite understood it. In the confusion, there was money to be made. Mere weeks after the CNN documentary aired, the spike in CBD interest prompted the Financial Industry Regulatory Authority to issue an investor alert on marijuana stock scams: As the F.D.A. would later show, many online CBD products contained little or no CBD whatsoever.

In 2020, CBD is available three ways: over the counter; at state-licensed marijuana dispensaries; or if you have certain forms of epilepsy, from GW Pharmaceuticals. Most Americans encounter CBD in the first and most unreliable way — at, say, a bodega in Brooklyn or a health food store in Indiana. A consultant hired to do an investigation by a corporate chain recently told me that the percentage of over-the-counter CBD products that contained the amount on the label was “in the single digits.”

As if CBD’s back story couldn’t get any weirder, the path to this glut of phony CBD was paved by, of all people, the Senate majority leader, Mitch McConnell.

Unrelated to the brouhaha on the West Coast, tobacco farmers in Kentucky were seeking a new cash crop. In 2011, James Comer won the race for Kentucky state agriculture commissioner by promising to legalize industrial hemp.

“That raised a lot of eyebrows, including in McConnell’s office,” Eric Steenstra, a hemp lobbyist, told me. “They saw the winds were shifting.”

Along with Representative Jared Polis, now the governor of Colorado, Mr. McConnell included a hemp pilot program in the 2014 farm bill — for “research.” In the legislation, hemp was defined as cannabis containing less than 0.3 percent THC — an arbitrary threshold, not a scientific distinction: Nothing in the Farm Bill, in case law, or in the Controlled Substances Act seemed to say anything about CBD. So entrepreneurs interpreted this research-oriented pilot program as the de facto legalization of cannabidiol.

The Drug Enforcement Administration disagreed, but couldn’t stop the tidal wave of CBD production. In 2018, over 60 percent of the hemp crop in Kentucky was grown for CBD. Then, long after the country was already flooded with CBD products both dubious and legitimate, Mr. McConnell inserted language into the 2018 Farm Bill explicitly making hemp federally legal.

Many of the Californians who plotted at Ms. Miller’s house in 2011 have watched in frustration as the CBD industry flourished, divorced from THC, and fake CBD misled consumers.

On his deathbed in 2014, Mr. Ringo insisted to friends and family that the Stanleys used his seeds to develop their famous strain Charlotte’s Web. Joel Stanley told me the genetics for Charlotte’s Web were a “cross of wild hemp with an industry genetic.” Critics of the Stanley brothers in the cannabis industry have grown annoyed by their prominence and push for patents. Their company has been valued at over half a billion dollars.

Ms. Miller, who still runs a cannabis testing lab, told me that in the years since the 2011 summit, she has become disillusioned as people she’d thought had earnest intentions in spreading CBD turned out to just want to get rich. Mr. Gardner feels the same way.

There has been a slight uptick in clinical research around the compound’s relation to anxiety, schizophrenia and opioid use disorder. In September, the National Institutes of Health approved $3 million in small grants for studies of cannabidiol and other non-THC cannabis compounds. Nevertheless, the government-enabled ham-handed rush to profiteering has seriously, and unduly, undermined CBD’s medical reputation.

Even Dr. Turner, Mr. Reagan’s drug czar, said there is far more evidence for the benefits of Sativex, the half-CBD, half-THC drug, than for unregulated CBD online.

“There haven’t been enough clinical trials and there never will be,” said Mr. Clarke, the cannabis seed collector. “There’s no vested financial interest in anyone doing it.” Big Pharma is most invested in medications that they can control, that they alone can patent.

Still, some of the states with legal cannabis have implemented robust testing standards, and bona fide CBD can be found at many marijuana dispensaries, both on its own and in a variety of ratios with THC. Ms. Miller’s lab, and other responsible actors, are supposed to ensure products that hit legal pot shop shelves contain exactly what they claim to contain. But without stringent federal oversight, few in the CBD business will voluntarily opt-in to tests of their product labeling’s accuracy.

When I asked Dr. Russo, who oversaw much of GW Pharmaceuticals’ research, how he feels about it all, he sighed. “You do something, and other people run with it, and it turns into something else that you don’t recognize,” he said. “I’m always concerned, but what I like to dwell upon is: What is the real potential here?”

Amanda Chicago Lewis (@msamandalewis) is an investigative reporter, focusing on drug policy. She has written for Rolling Stone, The Wall Street Journal, GQ Magazine and other outlets.