Updated on November 22, 2023
5 min read

Phenibut (Effects, Anxiety, Depression & Risks)

What is Phenibut? 

β-phenyl-γ-aminobutyric acid, or phenibut, is a nootropic drug. It's a central nervous system depressant whose chemical structure resembles the neurotransmitter GABA (gamma-aminobutyric acid).1,4 This neurotransmitter is known to:1,4

  • Reduce anxiety
  • Reduce excitability
  • Induce calm
  • Promote Relaxation
  • Enhance cognitive function
  • Produce a sense of euphoria

Because of this, phenibut has been studied to treat anxiety and depression. Due to safety concerns, it's not approved in the US for use in dietary supplements. However, it is legally sold online as a nutritional supplement.7


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Is Phenibut Regulated in the United States?

According to the Morbidity and Mortality Weekly Report from the U.S. Department of Health and Human Services, phenibut is an unregulated substance.5 It's not licensed in the United States, Australia, and the European Union.

Phenibut is not FDA-approved and has been rejected by Australia's Therapeutic Goods Administration (TGA) due to the risk of overdose. However, according to the Centers for Disease Control and Prevention (CDC), it's not illegal to possess.4,7

What is Phenibut Used For? 

Phenibut is considered a neuropsychotropic drug that affects the central nervous system. It can penetrate the blood-brain barrier and affect your mental state.1,4

Because of this, it's used to treat the following conditions:

  • Alcohol use disorder 
  • Alcohol withdrawal syndrome
  • Depression
  • Insomnia
  • Irregular heartbeat
  • Post-traumatic stress disorder
  • Stuttering
  • Vestibular disorders such as vertigo

Phenibut has also been known to:1,4

  • Enhance learning ability and memory
  • Help the brain function under stressful situations
  • Increase neuronal activity
  • Reduce social anxiety

In certain cases, phenibut can be used as a post-operative medication to alleviate tension and promote relaxation.

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Side Effects & Dangers of Phenibut 

It's difficult to keep track of phenibut's side effects because it's not regulated for use. However, its side effects are minimal, especially when taken in small doses. Its effects tend to last between 2 to 5 hours.

Some of the most common side effects associated with Phenibut use are:4,8

  • Allergic reactions to the drug
  • Headaches
  • Irritability
  • Increased anxiety
  • Tiredness
  • Upset stomach

Severe Side Effects of Phenibut

The side effects can vary greatly depending on the dosage. When taken in higher doses, the side effects become more intense and, in some cases, dangerous.

Heavy usage or abuse leads to:4,8

  • Motor impairment
  • Loss of coordination
  • A hangover feeling
  • Slowed breathing
  • Eosinophilia
  • Fatty liver disease

Chronic use can also lead to physical dependence, withdrawal, depression, and fatigue.3 Contact a medical professional immediately if you or someone you know is abusing phenibut.

Other Risks of Taking Phenibut

Phenibut exposures reported to poison control centers are increasing. During 2009–2019, U.S. poison centers reported calls for 1,320 phenibut exposures from all 50 states.5

Because of this, it's important to understand the risks and dangers of phenibut use. These include:

Phenibut Drug Interactions

Phenibut can interact with pregabalin because they act on the brain similarly. Taking these two substances together can increase the risk of side effects. It can also interact with other CNS depressants and sedatives, leading to sleepiness and breathing problems.

Acute Phenibut Toxicity

Acute toxicity can happen to a person taking Phenibut. The most common clinical effects reported are lethargy and sedation but may also include the following:4

  • Agitation
  • Bradycardia (slow heart rate)
  • Confusion
  • Delirium
  • Nausea
  • Tonic-clonic seizures
  • Vomiting


An overdose happens when a user takes Phenibut in very high doses. The most common symptoms of Phenibut overdose are:2

  • Excessive muscle relaxation
  • Hypothermia (lowered body temperature)
  • Hypotension (reduced blood pressure)
  • Respiratory depression
  • Sleepiness

Withdrawal Symptoms 

Withdrawal occurs after chronic use, and withdrawal symptoms can sometimes last two weeks or longer.

Withdrawal symptoms include:2

  • Agitation
  • Anxiety
  • Depression
  • Fatigue
  • Hallucinations
  • Hyperkinesia/Hyperactivity
  • Nausea
  • Insomnia
  • Tachycardia (fast heart rate)
  • Tremors
  • Psychosis
  • Vomiting

Does Phenibut Produce a High?

Yes, phenibut can produce a "high", especially in higher doses. However, even a small amount of phenibut can get first-time users high.2

Phenibut's high has a delayed onset, making people believe it's not working. This can them to take additional or higher doses of phenibut, increasing the risk of an overdose.2

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Is Phenibut Addictive?

You can develop a physical dependence on phenibut, especially with long-term use. As a result, you're compelled to use phenibut more often, leading to misuse and psychological addiction.2,3

A phenibut dependence occurs due to its effect on your dopamine receptors.3 Increasing dopamine levels in the brain can lead to feelings of pleasure and euphoria, contributing to addiction and compulsive use.2

People who use phenibut as an anxiety reducer, cognitive enhancer, or sleep aid are at risk of becoming tolerant to it. This increases the likelihood of abusing the drug. If suspect an addiction to phenibut, seek professional medical advice.2

Signs of Phenibut Use & Addiction

The signs of phenibut addiction and misuse may include:2

  • Frequent cravings for Phenibut
  • Using Phenibut in larger doses than initially intended
  • Using Phenibut for a longer period than initially intended
  • Spending a lot of money to acquire Phenibut
  • Using Phenibut as a tool to cope with everyday stressors
  • Placing their addiction before all other obligations at home, work, or school
  • Using Phenibut despite the problems that it causes at work, in school, and with family or friends
  • Having financial issues associated with buying more Phenibut
  • Experiencing tolerance and/or Phenibut withdrawal symptoms
  • Higher incidence of side effects with increasing severity

Treatment for Phenibut Abuse & Addiction

If someone you know is addicted to Phenibut, know that it is not a hopeless case. Phenibut abuse and addiction can be treated using different methods. Addiction treatment would include:

  • Gradual tapering: This method involves gradually reducing your dosage to help avoid withdrawal symptoms
  • Inpatient treatment: Involves checking yourself into a rehab facility for 24-hour medical supervision
  • Outpatient treatment: A treatment program where you are freely allowed to leave the rehab facility
  • Detoxification: A medically supervised detox to help remove the body from your system with minimal withdrawal symptoms
  • Medication-assisted treatment: Involves using medication, counseling, and therapy to treat addiction
  • Cognitive Behavioral Therapy: A therapy technique used to treat drug, alcohol, and substance use disorders (SUD) by exploring the link between thought patterns and substance abuse
  • 12-step programs: Support groups that follow a 12-step process designed to help guide individuals through recovery and maintain sobriety

It's important to understand that people react to treatment differently. Talk to a healthcare provider to explore different treatment programs that cater to your needs.

Other Names for Phenibut

Phenibut is a licensed pharmaceutical drug in Eastern European countries like Russia. It's prescribed to treat anxiety under the brand names:4

  • Noofen
  • Fenibut
  • Avifen

However, it's also used as a recreational drug called "party powder" and "but".

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Updated on November 22, 2023
8 sources cited
Updated on November 22, 2023
  1. Lapin, I. “Phenibut (beta-phenyl-GABA): a tranquilizer and nootropic drug.” CNS drug reviews, 2001.

  2. Zheng et al. "Phenibut Addiction in a Patient with Substance Use Disorder." Cureus, 2019.

  3. Samokhvalov et al. "Phenibut Dependence," BMJ Case Reports, 2013.

  4. Owen et al. “Phenibut (4-amino-3-phenyl-butyric acid): Availability, prevalence of use, desired effects and acute toxicity.” Drug and alcohol review, 2016.

  5. Graves et al. "Notes from the Field: Phenibut Exposures Reported to Poison Centers — United States, 2009–2019," Centers for Disease Control and Prevention, 2020

  6. Hardman et al. “Acute phenibut withdrawal: A comprehensive literature review and illustrative case report,” Bosn J of Basic Med Sci, 2019.

  7. Cohen et al. "Quantity of phenibut in dietary supplements before and after FDA warnings." Clin Toxicol (Phila), 2022.

  8. Acosta E & Munguti C. "Acute Psychosis Associated with Phenibut Ingestion." Kans J Med, 2021.

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