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Phenibut (beta-phenyl-GABA) is a central depressant used to treat a wide range of ailments including posttraumatic stress disorder, depression, and alcoholism. Read more below to learn about its health benefits.

Introduction: What is Phenibut?

Phenibut is a synthetic drug that is structurally similar to natural brain chemical called gamma-aminobutyric acid (GABA) that has a calming effect on the brain (R).

Phenibut, also known as fenibut, is sold under the brand names of Noofen and Citrocard (R).

Phenibut was developed in Russia in the 1960s, and has since been used as a prescribed drug to relieve tension, anxiety, posttraumatic stress disorder, depression, and other conditions (R).

It is not FDA approved for clinical use in the United States. However, it is sold as a nutritional supplement, but withdrawal and dependency have been reported in those who are not under doctor’s supervision (R).

Health Benefits of Phenibut

Most health benefits of phenibut are based on studies in animals. However, not enough data is available to demonstrate effects of phenibut in humans.

1) Phenibut is Neuroprotective


In rats, phenibut reduced amnesia, and improved decreased blood flow, and sensory and movement deficit caused by stroke (RR2).

In addition, it decreased the severity of amnesia and behavioral deficit in rats exposed to electroshock (R).

Phenibut also decreased nerve pain (R).

Study also showed that phenibut protected rat neuroblastoma cells from hydrogen peroxide damage in a dose-dependent manner (R).

2) Phenibut May Help Improve Cognition


Phenibut may have nootropic (cognition enhancing) activity, thus it may improve motivation, attention, and concentration.

Phenibut accelerates the development of defensive reflexes at an early stage of conditioning, and facilitate the development of conditioned inhibition (R).

Phenibut improved learning in rabbits by enhancing brain responses to stimuli (R).

It improved passive avoidance conditioning, and helped prevent amnesia caused by scopolamine (a sedative) or electroshock (RR2).

3) Phenibut May Reduce Anxiety and Aggression

In animals, phenibut decreased fear and anxiety, and facilitated escape from stressful situations (RR2).

In rats, phenibut decreased aggression when provoked (R).

4) Phenibut May Protect the Heart


In animal models, phenibut and nitric oxide protect the heart by reducing heart rate and contractility in stressful situations (RR2).

In combination with nicotinic acid, it reduced disturbances in blood flow after stroke in animals (R).

Phenibut may prevent heart damage in alcohol intoxication (R).

Also, studies showed that phenibut may regulate heart rhythm (R).

In pregnant rats with preeclampsia, phenibut prevented blood pressure increase, decreased protein levels in urine, increased blood flow in the uterus, and normalized blood flow and platelet formation (RR2).

5) Phenibut May Help Prevent Alcohol Dependence

In animals, phenibut citrate prevented damage caused by alcohol (R).

It also reduced motivation to attain and drink alcohol (R).

6) Phenibut Helps Protect the Immune System

Phenibut regulates the immune system when it is overactive, and restores the amount of phagocytic cells (cells that engulf microbes) (R).

In rats and mice, phenibut restored the immune system after it was suppressed using cyclophosphamide (R).

7) Phenibut May Help Treat Respiratory Problems


In rats, phenibut prevented apnea (breathing cessation) caused by serotonin (R).

The phenibut injection increased duration of inhalation during exposure to negative emotional stimuli (R).

Side Effects and Cautions

Two people with elevated phenibut levels were experiencing symptoms of delirium and decreased consciousness, indicating that excessive levels may be toxic (R).

Side effects of phenibut include headache and depression. An overdose of phenibut can result in lowered body temperature, muscle relaxation and sleepiness (R).

Withdrawal symptoms include severe anxiety, irritation, dizziness, fatigue, loss of appetite, insomnia, muscle twitches, heart palpitations, hallucinations, and confusion (RR2).

Phenibut has abuse potential and should not be considered as a supplement, but rather as a medication (R).


  • The addition of the phenyl group to GABA enables the compound to cross the blood-brain barrier and enter the brain (R)
  • Phenibut increases the release of dopamine and blocks β-phenylethylamine (PEA) (R)
  • It also mimicks the nootropic GABA by binding to GABA-b and to some extent to GABA-a receptors (R)


FDA Compliance

The information on this website has not been evaluated by the Food & Drug Administration or any other medical body. We do not aim to diagnose, treat, cure or prevent any illness or disease. Information is shared for educational purposes only. You must consult your doctor before acting on any content on this website, especially if you are pregnant, nursing, taking medication, or have a medical condition.


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  • Ijon

    F-phenibut is about 8-10 times more potent than regular phennibut.

  • Andrew

    What about F-Phenibut (Fluorophenibut)? Is it really a several-fold more potent than regular phennibut and similar to Baclofen?

  • Dean

    I use it before bedtime to make my dreams more interesting. I think it works better if I take a couple days off each week.

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