Chemically, phenibut is similar to the neurotransmitter GABA (gamma-aminobutyric acid), which reduces the excitability of brain cells. That helps explain why people report feeling relaxed and happy when they take it. “It helped me deal with social anxiety without clouding my mind,” Willis says. In that sense, says University of Michigan psychiatrist Edward Jouney, phenibut is actually a close cousin to drugs in the benzodiazepine family, which also affect the brain’s GABA receptors.
Phenibut’s short-term effects are highly dependent on what dose you take. If you take a small amount, under 1 gram, you’re likely to feel a sense of calm and well-being. But at higher doses, your thinking typically blurs, your motor coordination gets loopy and you may lapse into a deep sleep.
Flirting With Dependence
Phenibut’s similarity to benzos means that — despite the popular perception that the drug is safe — your brain can start to grow dependent on it over time, just as it would on Valium or Xanax. “The drug has very potent psychoactive properties,” Jouney says. “There’s evidence it can cause addiction.”
Jouney began researching phenibut’s effects a few years ago, when patients at his clinic told him they’d started the drug and were finding it impossible to stop. The deeper he dug, the more uneasy he became.
Not only were users reporting growing dependence on phenibut, but cases of phenibut-related dissociation, psychosis, and respiratory depression were also cropping up around the country. The CDC reports that poison center calls related to phenibut have been growing since 2015, with users experiencing symptoms like agitation, irregular heartbeat, confusion and even coma.
A Pharmaceutical Wild West
Jouney thinks it’s possible that, used under a doctor’s supervision, phenibut could one day prove a viable treatment for anxiety. The trouble is that clear evidence of the drug’s safety and effectiveness is lacking — and to add to the potential danger, many people are purchasing phenibut from unregulated online sellers.
Phenibut is technically legal to possess in the United States, but that doesn’t mean it’s risk-free — or that you get what you pay for when you order it. Jouney contacted several online phenibut suppliers to ask about their products and quality-control measures, but was rebuffed: “I tried calling them and they wouldn’t give me any info.” In 2019, the FDA sent warning letters to three companies for branding their phenibut products as “dietary supplements,” but most online phenibut sellers continue to ply their wares unchecked.
While Delynn Willis’s phenibut journey started off smoothly, she soon experienced the backlash many users describe. “After I had been using it for a few weeks, I started to notice I needed higher and higher doses to get the same effect,” she says. She started weaning herself off of the drug and got hit with a torrent of withdrawal symptoms. “My anxiety skyrocketed, my temper shortened and I experienced dizzy spells.”
That kind of torturous backlash is why Jouney urges people to reject claims that phenibut is a safe Xanax alternative. “It’s something that should be regulated,” he says. “It can lead to physical dependence. This is not a benign substance.”