Medically Reviewed

Phenibut Addiction, Side Effects, Withdrawal, and Treatment

2 min read · 6 sections

Phenibut is an unregulated antianxiety drug with cognition-enhancing properties.1 It is readily available for purchase online where it is marketed as a supplement for anxiety, relaxation, sleep, as well as to help manage symptoms of depression and post traumatic stress disorder (PTSD).2 However, phenibut is not without risks.3

What is Phenibut?

Developed in Russia in the 1960s, phenibut (β-phenyl-aminobutyric acid) is a psychoactive substance still widely used there to relieve tension, anxiety, alcohol withdrawal, stammering, and insomnia, and to potentiate neuroleptics and antiparkinsonian drugs.4 It is a controlled substance in Australia and banned in Hungary, Lithuania, and Italy.4 In the United States (and most of Europe), it is legal to possess and sell phenibut—also referred to as Fenibut, Pbut, Noofen, and Brain Booster, among others—but it’s not approved as a licensed drug by the Food and Drug Administration (FDA), and is, therefore, not used in clinical settings.3,5,6

Phenibut is typically consumed orally, generally as either a powder that’s mixed with water, as tablets, or as a liquid solution. A small number of people reported snorting the powder form, but these instances led to painful nostril swelling.4

Phenibut Effects and Side Effects

Information on the effects of phenibut is somewhat limited to anecdotal evidence, gathered from user experience reported online, physicians who have encountered patients reporting phenibut toxicity (i.e., overdose), or withdrawal. Additionally, there are several published case reports. Individuals who use phenibut report using it to relieve symptoms of social anxiety or for use recreationally, claiming they use it to get “high,” or to produce the feelings of euphoria.4 Indeed, research suggests phenibut may increase the concentration of dopamine in low doses, which gives it a stimulant-like effect in addition to relieving anxiety.7

A wide range of side effects have also been reported, and they generally include symptoms associated with relaxation, drowsiness, and sedation. These include:5,8

  • Confusion.
  • High blood pressure.
  • Increased heart rate.
  • Muscle spasms.
  • Dilated pupils.
  • Irritability.
  • Delirium.
  • Seizures.
  • Slowed breathing.

More serious side effects, such as coma, respiratory depression, and death (in very rare instances) are often associated with using phenibut in combination with other central nervous system (CNS) depressants, such as alcohol.8

Long-Term Effects of Phenibut

The long-term effects of phenibut use are unknown and not well studied.8

Phenibut Tolerance

While robust clinical trials that include examining phenibut’s potential for addiction do not exist, there are case studies and anecdotal evidence that suggest that regular use likely leads to tolerance, which means more of the substance is needed to achieve the desired effect. In some individuals, tolerance occurred within a week of using phenibut regularly.6

Phenibut Dependence and Withdrawal

Several case studies point to evidence suggesting that regular phenibut use can lead to dependence.8 Dependence is a physiological adaptation of the body to a substance, meaning the body becomes so used to having the substance present that when the individual stops their use or significantly reduces their dose, withdrawal symptoms emerge. In some instances, individuals continue taking the substance to prevent the withdrawal symptoms from re-emerging.

Evidence suggests that individuals who use phenibut in conjunction with other substances, particularly with opioids or CNS depressants such as alcohol or sedatives, may experience more severe withdrawal symptoms.3,9

Dangers of Phenibut Use

There’s evidence that phenibut can be toxic and potentially dangerous. In the decade between 2009 and 2019, there were 1,320 phenibut exposure calls to poison control centers throughout the United States.3 Of these, 40.2% were adults aged 18 or older, who combined phenibut with another substance.3

Half of these cases reported moderate effects with no lasting impairment. However, coma was reported in 80 cases (6.2%), and major life-threatening effects occurred in 1 in 8 cases, including 3 deaths.3

Help for Phenibut Misuse and Polysubstance Misuse Treatment

If you or a loved one experience worrisome, adverse effects, including possible toxicity or withdrawal from phenibut use, see your doctor or seek emergency treatment.

There’s no data suggesting that addiction treatment is required or is efficacious for someone who is phenibut dependent.

However, if you or a loved one use phenibut in conjunction with other substances, treatment for polysubstance use (using multiple substances at the same time) might be necessary.

Many treatment centers offer individualized care to meet your specific needs, including the type and amount of substance or substances used. Additionally, lots of treatment facilities offer specialized programs for individuals with co-occurring mental health and substance use disorders.

Treatment may consist of medications for detox. For instance, research indicates that medications, such as Baclofen, may help individuals who have become dependent on phenibut during detox to ensure safety and minimize unpleasant withdrawal symptoms.1,10

Polysubstance use treatment typically also involves behavioral therapies to help you address the emotions, thoughts, and behaviors that led to polysubstance misuse.10

Reach out to an admissions counselor if you or a loved one struggle with polysubstance misuse to start your journey to recovery.

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