When Lauren Brenc was in her 20s and living in New York City, a night out with friends meant drinking.

“I was so programmed to have fun with alcohol, everything became centered around it,” said Brenc, who worked in bars and clubs at the time. “It was damaging my body, how I looked, my emotional well-being. Everything was suffering.”

That changed when she moved to Southern California in 2019. She cut down her drinking—and “started doing big doses of mushrooms,” Brenc said. Now 30 and living in Topanga Canyon, she hosts alcohol-free pop-up parties in the Los Angeles area where she serves “mood-enhancing” mocktails and mushroom chocolates.

Like many others, Brenc uses the term “California sober” to describe her way of life. Alcohol is largely off the table, but psychedelics are a big part of her social world. “I kind of just decipher what types of substances are going to raise my frequency and what isn’t,” she said. This very Los Angeles lifestyle is catching on, thanks in part to January’s surgeon general advisory about alcohol being a leading preventable cause of cancer. 

“Individuals are choosing what resonates with them instead of just doing what might be at the party,” said Atara Oven. The 38-year-old Santa Monica resident devotes her professional life to guiding people on preparing for psychedelic experiences and assisting them on “integration” afterward. In her social community, Oven said it’s common for people to abstain from alcohol but use cannabis, mushrooms , LSD and ketamine.

In 2019, she started dabbling with “plant medicine,” after cutting back on alcohol because she was tired of the hangovers and wanted different experiences. She hasn’t had a drink since November, she said, but she uses other substances. “I sit with Grandmother Ayahuasca when I’m called to do so. I recreationally and intuitively microdose,” she said. “I just don’t drink. It’s not a thing.”

Oven said there can be a kind of reverse peer pressure around not drinking. She tries to avoid influencing people. “When I’m out to dinner with a friend, I let them order their drinks first, because if I don’t order a drink then they may not,” she said. “I want it to be their choice.”

The so-called sober-curious movement —focused on drinking less without going cold turkey—has been growing for years, as influencers have raised concerns about alcohol and shared their own stories about reducing their consumption. Stanford neuroscientist Andrew Huberman hosts a popular podcast where he has spoken about the negative effects drinking may have on health .

All of this is changing how people socialize. Eventbrite, the event ticketing platform, said that the number of events billed as “sober curious” grew 92% on its platform from 2023 to 2024, and attendance increased 51% over the same period. According to a study put out by the company in January , one in five 18- to 35-year-olds are seeking alcohol-free or sober-curious events.

Other substances, including psychedelics, have taken alcohol’s place in certain social settings.

Psychedelics can be abused or lead to unpredictable and harmful outcomes when used recreationally. Some, such as LSD and psilocybin, have shown potential for treating mental-health conditions when used in therapeutic settings . As a result, some states and local governments have relaxed their stance on the federally prohibited class of drugs. Last fall, Robert F. Kennedy Jr., the newly confirmed Health and Human Services secretary, posted to social media that his “mind is open to the idea of psychedelics for treatment.” A former heroin addict who is 40 years into recovery, Kennedy recounted his son’s positive experience with ayahuasca and believes psychedelics should be decriminalized.

Cannabis, the original drug of choice for the “Cali sober” set, has been widely legalized for recreational use.

Many of the drugs embraced by the sober curious have not been studied as extensively by scientists. Alcohol, on the other hand, has been the subject of studies for decades, yielding a large body of research that documents its potential harm.

“There’s certain communities and scenes where if you are trying to drink, it is actually viewed as odd,” said Jeff Chen, a physician, scientist and entrepreneur in Los Angeles who used to run UCLA’s Center for Cannabis and Cannabinoids. He said people are gravitating from booze to other substances for reasons that include broader awareness and acceptance of the long-term effects of alcohol. Chen said the highs of mushrooms, cannabis and even ketamine can have a different effect on human connection. Ketamine—which has become an off-label mental-health treatment in recent years but can be abused in unsupervised settings—can go in and out of the system relatively quickly, he said, which is a benefit for those who want to snap back to “normal” quickly and avoid the hangover that may follow a night of drinking.

Chen said research on the recreational use of cannabis and psilocybin shows the substances can be less physically harmful and less addictive than alcohol, but because the recreational use of ketamine is newer, there’s not enough research to compare. He said there are significant physical and mental-health risks to recreational ketamine use, and people should be cautious about the long-term mental-health effects of recreational use of cannabis and psilocybin, especially in adolescents and those with any history of psychotic conditions.

Chen is the CEO of a wellness-tech startup, Radicle Science, that runs crowdsourced clinical trials on consumer packaged goods and supplements to understand their medical potential. Chen said Radicle Science has recently been contacted by companies that want to study euphoria enhancement from nonalcoholic products that contain legal ingredients. Radicle has already studied the effects various products—including hemp beverages and products containing adaptogens—have on relaxation and stress reduction.

Ford Smith, an investor who lives in Austin, went to rehab as a teen to address his alcohol addiction. He was sober until he was 26, when he decided to see if cannabis could help his depression and ADHD. He’s explored psychedelics such as psilocybin, which he said eased his depression and anxiety, as well as substances including Ayahuasca and iboga. Today, Smith is 33 and is the CEO of a venture firm called Ultranative that is focused on the environment and alternative medicine. Ultranative is an investor in Radicle Science.

After first being introduced to ketamine on a dance floor in Tulum in 2017, Smith eventually sought out intravenous ketamine infusions at a clinic back home. He said the infusions helped with his depression, but eventually sought out a drug dealer for easier access.

He became addicted, he said, using ketamine daily for over two years before going to rehab for ketamine addiction. “I know countless numbers of people who’ve either been in the same addiction with ketamine or are struggling with it currently,” he said. “People are a little too laissez-faire about how they’re using ketamine.”

Kayla Lyons, the author of the 2023 self-help book “Soberish,” went to rehab about a decade ago to recover from a benzodiazepine addiction. A year later, she went to Alcoholics Anonymous to get a handle on her drinking. Now 32 and living in Newport Beach, Lyons says total sobriety doesn’t work for her. She’s tried other substances, from psilocybin to a tonic that contains the herbal substances kratom and kava. America’s Poison Centers, which collects data for all 55 poison centers in the U.S., identified unregulated psychoactive substances including kratom as an emerging public health threat and has led to hospitalizations.

“It makes you feel like you’re kind of drunk, but not wasted,” she said, adding that she told her older brother to try it for relaxation. “He started drinking two or three bottles a day and then getting serious withdrawal symptoms.”

Lyons, a Lagree instructor, said she stays away from that now, too, and doesn’t recommend it to others. Her social activities include meetups involving coffee and cold plunges, and sound baths.

“I have found a really strong community of sober, or basically sober, people who really don’t drink,” she said. “It’s more, ‘Let’s go for a hike, let’s go for a walk, let’s have a vision boarding night or go grab a juice.’”

Write to Sara Ashley O’Brien at sara.obrien@wsj.com