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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.

Note: By writing this post, we are not recommending this drug. Some of our readers who were already taking the drug requested that we commission a post on it, and we are simply providing information that is available in the scientific literature. Please discuss your medications with your doctor.

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).

Uses 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)

Health Tools I Wish I Had When I Was Sick

At SelfHacked, it’s our goal to offer our readers all the tools possible to get optimally healthy. When I was struggling with chronic health issues I felt stuck because I didn’t have any tools to help me get better. I had to spend literally thousands of hours trying to read through studies on pubmed to figure out how the body worked and how to fix it.

That’s why I decided to create tools that will help others cut down the guesswork:

  • Lab Test Analyzer – a software tool that will analyze your labs and tell you what the optimal values are for each marker — as well as provide you with actionable tips and personalized health and lifestyle recommendations to help you get there.
  • SelfDecode – a software tool that will help you analyze your genetic data from companies such as 23andme and ancestry. You will learn how your health is being impacted by your genes, and how to use this knowledge to your advantage.
  • SelfHacked Secrets – an ebook where we examine and explain the biggest overlooked environmental factors that cause disease. This ebook is a great place to start your journey if you want to learn the essential steps to optimizing your health.
  • SelfHacked Elimination Diet course – a video course that will help you figure out which diet works best for you
  • Selfhacked Inflammation course – a video course on inflammation and how to bring it down
  • Biohacking insomnia – an ebook on how to get great sleep
  • Lectin Avoidance Cookbook – an e-cookbook for people with food sensitivities
  • BrainGauge – a device that detects subtle brain changes and allows you to test what’s working for you
  • SelfHacked VIP – an area where you can ask me (Joe) questions about health topics

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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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  • Lisa W

    I took it for a few months like 6 years ago and still have side negative effects from it. I stopped because it caused me to clench my jaw really tight at night to the point that it was sore in the morning, have really intense dreams that would make me sweat profusely while sleeping and I’d wake up panting and heart pounding. I still have the teeth clenching and sweating while sleeping (so freaking annoying) and the dreams are about half as intense. Sucks to still have these effects years later. Wish I never took it.

  • Neckbeard

    Phenibut is weird. Your mental state isn’t affected very much (i.e. you’re basically sober when you’re on it), but the after effects are like coming down off of drugs. I would stay away from it unless you’re looking for a ‘legal high’ – in which case you should take it before you drink alcohol.

  • 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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