Every morning for the past two years, 35-year-old Mark (not his real name) has woken up at 6 a.m., reached into his well-stocked vitamin cabinet and measured out exactly 2.5 grams of a drug he says makes him the smartest, funniest and most energetic person in the room. He tips the bitter white powder straight from the scale into his mouth, washing it down with a sugar-free energy drink before he skips off to his tech management job, where he says the drug has made him successful way beyond his potential.

Without this drug, Mark’s anxiety and depression get so bad that he can’t make phone calls, interact with people or function at work. With it, he’s the person who commands the attention in the room. “It literally changed my life,” he tells me over Reddit DM. “I would be a completely different person without it.”

The drug he’s taking is phenibut, a completely legal “smart drug” that’s been hailed by users as a psychotropic panacea for seemingly everything.

Because it mimics the neurotransmitter GABA and boosts the brain’s supply of dopamine, phenibut is particularly good at shushing central nervous system responses that lead to nervousness, anxiety and inhibition. This makes it a handy anxiolytic, but it’s also used commonly used as a sedative, mood regulator and cognitive enhancer as well. In countries like Russia, Ukraine and Latvia, where it’s licensed for medical use, it’s often prescribed to treat PTSD, depression, insomnia, low libido, vertigo, alcohol withdrawal and, most notably, anxiety. In fact, it’s such an all-purpose workhorse that it was once given to Russian cosmonauts in their standard-issue medical kits to help them cope with the stress and disorientation of space flight.

Phenibut has been around since the 1960s. It was developed in Soviet Russia as an anti-anxiety medication, but according to Edward Jouney, director of the Addiction Psychiatry Fellowship Program at the University of Michigan School of Medicine, its popularity as a recreational drug has begun to sweep across Europe to the United States in the past few years. During that time, Google searches for phenibut have skyrocketed as a growing amount of online retailers like NootropicsDepot and LiftMode add it to their inventory and internet fora like Reddit and Drugs-Forum have exploded with user stories and discussions that were absent just a few years prior. The growing demand for “pheny” has also democratized pricing. It’s always been cheap, but now, a 5-gram tub of it can be yours for the low cost of just $7.88 (that’ll last you about a week or two, depending on how often and how much you dose.) And while Jouney says the phenibut craze is so new that no studies have attempted to quantify its rise in the U.S., he assures me that there is “no question” that it’s fast becoming one of the internet’s most popular new drugs.

There are many reasons for this — its reputation as a cure-all being one of them — but the way it’s marketed and represented in social media has a lot to do with it. For example: there’s an Instagram account called @phenibutmemes that posts phenibut glorification content like this:

Know what the bio for the page is? “Absolutely litty and extremely legal.”

When whoever runs this account says “litty” — which they do every chance it gets — what they mean is that phenibut can also get you really high. When used recreationally, it can decrease inhibition, induce feelings of euphoria, make music sound better, enhance meditation practices and, according to Reddit, make people feel like they’re on MDMA or non-drowsy benzos or like they’ve “just downed six shots of vodka.”

It can also make you horny, apparently. Thirty-two year-old Samuel, a sales representative who uses phenibut to treat his anxiety and depression, says that while phenibut really helps him with empathy and productivity, his favorite effect is how much it increases his libido and stamina in bed. “It makes sex absolutely amazing,” he says, noting that it turns his normally prudish wife — also a phenibut user — into an “animal.”

But it’s not just the high or the therapeutic benefits users report that make phenibut such an interesting specimen. Rather, it’s the common insistence that it changes people’s lives.

Both Mark and Samuel credit it as the reason they’re able to rise above their personal obstacles, and other glowing reviews from like-minded redditors make it seem like some sort of perfect solution gushed over like a Slap Chop-esque product on a late-night public access infomercial. “I’ve taken 1 gram once a week for six years and still enjoy that moment when I wake up, open my eyes and my world has changed for the better,” says Sniffing_Dog, in response to my post. “Phenibut doesn’t give you newfound jokes and expressions to use in social situations, it only frees you up from whatever might be holding you back,” writes another user in a separate post.

Collectively, users often refer to these effects as “phenibut magic,” but experts like Jouney and psychologist and pharmacological epidemiologist Larissa Maier urge that they be taken with a giant grain of salt. Few of these effects have been properly investigated through research, she says, and data on phenibut as a substance for cognitive and/or mood enhancement is sorely lacking. The scant research that does exist is in German or Russian, and seems to be predominantly concerning animal trials, not human ones, so no one’s really sure what phenibut’s risks or long-term effects are. “The fact that it’s not regulated by the FDA should also be a big red flag,” says Jouney. “It’s important for people to know that phenibut has been proven neither safe or the panacea it’s made out to be.”

Thing is, phenibut users actually agree with this statement, which is where things really get interesting. As I discovered from talking to dozens of phenibut users on Reddit, even the people who love phenibut the most; the ones who claim it’s changed their lives and opened up a world of possibilities they might not have otherwise had, say it might be better for potential users to sit this one out.

Certain people communicated this to me more forcefully than others. “You should really stop bringing attention to this drug,” writes yalendfluv. “What if your story convinces somebody to get on phenibut, and they end up addicted, end up in the ER with some serious psychosis/delusions? You don’t want that on your psyche, now do you?”

Mark agrees. “I don’t want to sell it as a good thing or a wonder drug, mostly because of the risks, and I don’t want it to become mainstream and then outlawed,” he says. “There are horror stories all over the internet about it.”

He’s right, too. There are multiple case studies which describe some disturbing reactions to phenibut, one of which is the recent mass overdose of seven teenagers at a private school in Queensland, Australia, an event that resulted in Australia’s Therapeutic Goods Administration denouncing phenibut as a healthful supplement and warning that it “represents a significant risk of harm, including overdose.” Word to the wise: Alcohol significantly increases the chances of that happening.

And while overdose is rare and hasn’t been associated with any deaths so far, taking too much phenibut is likely to produce as many undesirable side effects as it is desirable ones. Diarrhea seems to be the main one: Phenibut is infamous online for its gastrointestinal side effects, which include nausea, vomiting, diarrhea and — no joke — sharting. Some users have also reported visual disturbances, tremors, tinnitus, extreme sleepiness and other assorted disconcerting central-nervous-system symptoms like headache, insomnia, confusion and depression. Others, like FortunatoLucrese, have less-intense side effects, but say phenibut just made them feel “listless” and “off” enough to scare them away for good.

Some phenibut users can also develop a tolerance to the drug within days of their first dose, making it so they have to take much more of it to feel the same effects. This can increase the risk of bad reactions and might even lead to withdrawal symptoms like severe rebound anxiety, insomnia and psychosis.

Redditor Smokey878 knows first hand what phenibut withdrawal is like. The first time he took it, he felt amazing, like he was rolling on MDMA. He started with a gram in the mornings, but developed a rapid tolerance. After just a month, he needed nine grams a day to feel the same effect, which is far beyond the recommended dose (which, by the way, is recommended by users, not medical professionals or researchers). It started to feel speedy rather than euphoric, and he chewed up the insides of his cheeks as he became wracked with anxiety. Then the sleeping problems started. “I would be up for days at a time,” he says. “Eventually, it pretty much threw me into psychosis.” He couldn’t finish simple tasks and suffered from extreme panic, which, ironically, was one of the things he started taking it to treat. “Some people use this responsibly I’m sure but I’ll never touch it again,” he tells me.

Paradoxically, some people never become addicted or build a tolerance to phenibut. Samuel says he’s heard many stories about addiction and withdrawal, but he’s personally never experienced any adverse effects whatsoever. Likewise, r/phenibut moderator BobDee tells me he’s been using it responsibly at low doses for years without a hitch, and multiple other users who responded to my Reddit post also said they’d never had issues or negative side effects. But for every person with a positive story, it seems like there’s another with the opposite. Carly, a 44-year-old stay-at-home mom who started taking phenibut a few months ago to try to kick her alcohol habit, tells me that she wakes up every day wishing she’d never touched the stuff.

“It’s so important for people to know that this is not a wonder drug,” she says. “I thought it was for the first few weeks because I felt great without booze, but I’ve become completely dependent on it in a scary way I never expected to be, especially given that it’s legal and you can get it for less than a fancy cocktail.” She’s tried kicking it a few times, but says ratcheting down her doses makes her feel “insane.”

“I’ve never wanted a drink more than when I’m trying to get off phenibut, which sucks extra for me because it’s totally changed my tolerance,” she says. “Two drinks, and I’m beyond gone, unable to function. I feel like I’m stuck between two worlds I don’t want to be in.”

Perhaps that’s why Reddit also has its own phenibut addiction community, r/quittingphenibut, a running list of adverse effects and overdoses covered in research and the news, and the unfortunate reputation of being the “most unpredictable supplement.” For being such a “life-changing” cure-all, it is really hit or miss.

Jouney says the difference in hits and misses is the same difference that underlies the reasons why all addictions affect some people and not others. “It’s a multifaceted combination of genetics, personal neurobiology, co-existing psychological conditions, what someone’s psychosocial situation is like and what sort of environment they live in,” he says. “Some people just have unique biological and environmental make-ups that render them more vulnerable to addiction and negative side effects.”

But without more research into phenibut’s effects or any regulatory efforts to standardize its dosage or quality, it’s hard to know who will benefit from phenibut, who won’t and what that means for the users who love it. In any case, he says, it’s clear that phenibut is not a panacea. “There’s no question that the drug has psychoactive properties and some therapeutic benefits, but those haven’t been studied in depth,” he explains. “It’s not being regulated, it’s not being prescribed, and it’s barely being studied, so I’d wholeheartedly hesitate to recommend it as a solution that anyone try.”

Jouney is even skeptical to endorse phenibut for people like Mark and Samuel for whom phenibut has been a life-saver, if only because it’s a Band-Aid for their problems, not an actual solution. “If someone is having any type of an emotional problem or if they feel they’re not doing well in some part of their life, they need to be evaluated properly by a licensed mental healthcare provider,” he says. “It might be that they don’t even need a drug. We live in a society where everyone wants a pill that’ll solve all their problems, but a pill [or in this case, a powder] can’t do that. It just masks them. If they’re suffering from something that needs to be talked about and processed, a mask isn’t going to help.” I’m not sure whether Mark or Samuel would agree that their particular mask isn’t helping, but Jouney’s right: Any “limitless pill” is a temporary salve (especially considering the FDA has already caught wind of phenibut and its less-than-sterling side effects) and several high-profile products like Kin Euphorics have either removed it from their ingredient list or been discontinued altogether.

For that reason, anyone seeking a competitive edge or a push-button solution to their problems might do better to look into more regulated and well-researched nootropics and substances like modafinil or even psilocybin. However, Maier says that any cognitive-enhancer should be approached with caution, as there’s still an ominous lack of generalizable findings on their effectiveness and safety, even when they’re legal and well-prescribed. (Just look at fentanyl and where that’s gotten us.)

But because hardly anyone listens to warnings about drugs, let’s make like the Dutch and end with some harm reduction: If you’re thinking about trying phenibut, do your research first. Join a group like r/phenibut, talk to other users and see what’s worked for them. Read the sub’s comprehensive and research-backed phenibut guide, and familiarize yourself with what data does exist about its risks and function (Google Scholar is a good place to look). Don’t drink when you take it, make sure you’re not taking any other substances that could interact negatively with it, and get yourself a mental health outlet in case you need help getting off it or dealing with your problems in more than one way. Most importantly, start low and slow. Both Maier and BobDee recommend dipping your toes in with between 250 and 750 mg, and taking only a single dose about once a week. Anything more than that, and you’re on your own.