Phenibut Review: Dosage, Research, How it is Used in Russia, FAQs

June 13, 2024

Do you want to use Phenibut safely? If yes, this Phenibut guide is for you. We have prepared an in-depth Phenibut review with answers to some of the most frequently asked questions about this versatile drug. What form of Phenibut is more effective? What dose to take? Where is it produced? What are Phenibut’s benefits and side effects? All facts are supported by links to official Phenibut research.



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Phenibut Review: Dosage, Research, How it is Used in Russia, FAQs 4


Phenibut or β-Phenyl-γ-aminobutyric acid is also known as fenibut, anvifen and noofenis. It is a GABA-mimetic psychotropic drug that is clinically used in its racemic form. The preparation possesses anxiolytic and nootropic activity. And it is used as a mood elevator and a tranquilizer in case of anxiety or insomnia, nervous tics, as well as a sedative before surgery.


Structurally, Phenibut is similar to Baclofen, another clinically used GABA receptor agonist. Both Baclofen and Phenibut are used clinically in their racemic forms even though they could be separated into R- and S-enantiomers. 

It is important because there are two types of GABA (γ-aminobutyric acid) receptors in the brain: GABA-A and GABA-B. And both of them influence the brain in different ways. So, the R-enantiomer of Phenibut mostly has an impact on GABA-B receptors and is shown to be much more effective than S-enantiomer. Interestingly, the same thing is observed for Baclofen which is also a GABA-B receptor agonist.

Phenibut structure
Phenibut Review: Dosage, Research, How it is Used in Russia, FAQs 5

In the research devoted to the comparison of the two isomers of the substance along with its racemic form, it is shown that the antidepressant, antinociceptive and locomotor inhibiting activity of racemic Phenibut relies on R-enantiomer. And it correlates with the binding affinity of enantiomers of Phenibut to GABA-B receptors. [5]


Phenibut is a very versatile nootropic drug because it combines two opposite effects: tranquilizing and activating. On the one hand, it has a calming action; on the other hand, it activates the brain. That is one of the reasons why it is widely prescribed by doctors in former Soviet countries to treat ADHD, hyperactivity and lethargy

According to Dr Galushchak, nootropics are a very peculiar group of drugs with multidimensional effects. Phenibut as one of them manifests several ones: it activates the brain and makes you think clearer, and it treats anxiety, restlessness and hyperactivity. So what does Phenibut do? 

  • Phenibut improves the functional state of the brain by normalizing its metabolism and influence on cerebral blood flow.
  • It reduces vaso-vegetative symptoms, including headache, feeling of heaviness in the head, sleep disturbances, irritability and emotional lability. 
  • Phenibut increases physical and mental performance: attention, memory, speed and accuracy of sensory-motor reactions. 
  • It reduces manifestations of asthenia, i.e. improves well-being and motivation without sedation or agitation. 
  • Phenibut helps reduce anxiety, tension and restlessness, and normalizes sleep. 


Phenibut is a nootropic that facilitates GABA-mediated transmission of nerve impulses in the central nervous system (direct effect on GABAergic receptors).

It also has a tranquilizing effect, an activating effect, antiaggregant, antioxidant and some anticonvulsant effects.

Phenibut improves cerebral blood flow: increases volumetric and linear velocity, reduces vascular resistance, improves microcirculation, and has an anti-aggregant effect. It prolongs the latent period and shortens the duration and severity of nystagmus.

It does not affect choline and adrenoreceptors. In the elderly it does not cause depression of the central nervous system. The muscular relaxant after-effect is usually absent too. Phenibut reduces the depressing effect of ethanol on the central nervous system.

How can we better understand the effects of Phenibut? Listen to an interview with a qualified medical Dr Alexander Galushchak ⬇️


Phenibut has a high absorption rate. The drug penetrates easily into all tissues of the body and crosses the blood-brain barrier (BBB). About 0.1% of the administered dose of the drug penetrates into the brain tissue; in young and old people this indicator is much higher. 

Phenibut is evenly distributed in the liver and kidneys. 80–95% of the drug metabolizes in the liver, the metabolites are not pharmacologically active. Phenibut does not accumulate in the body. After 3 hours it begins to be secreted by the kidneys. However, its concentration in the brain tissue does not decrease and it can be found in the brain for another 6 hours which is Phenibut half-life. 

About 5% of the drug is excreted unchanged by the kidneys and partly with bile. 


According to the official instructions Phenibut is used in the following cases: 

  • Asthenic and anxiety-neurotic states;
  • Insomnia and night anxiety in the elderly;
  • Vestibular disorders, prevention of motion sickness, vertigo, Ménière’s disease;
  • Part of the complex treatment of alcohol withdrawal syndrome; reversal of psychopathological and somatic vegetative dysfunction;
  • Stammering, tics, enuresis in children.


Phenibut can be used as a quick fix for situational and social anxiety [15], for example prior to serious or stressful events: an exam, a wedding, a speech, etc. It has medium to strong anxiolytic effects equivalent to alcohol but is generally less powerful than benzodiazepines.

You may also look at Adaptol for similar purposes. It is a milder, but safer anxiolytic compared to Phenibut.


Phenibut is a prescription medication. It implies that the official dosage recommendations below are intended to be used only by medical professionals to determine the treatment regimen for patients with serious conditions.  

Official Phenibut instructions suggest the following dosages of Phenibut:

  • Adults: 250–500 mg 2-3 times a day. If necessary, the daily Phenibut dose can be increased up to 2500 mg. The single maximum dose is 750 mg, and in people over 60 years – 500 mg.
  • Children from 8 to 14 years old: 250 mg 2-3 times a day. The single maximum dose is 250 mg
  • Children from 3 to 8 years old: 50–100 mg 2-3 times a day. The single maximum dose is 150 mg.

Dosage of Phenibut: Alcohol Withdrawal

During the first days of treatment 250–500 mg 2-3 times a day and 750 mg at night. Then gradually reduce the daily dose to the standard one.

Dosage of Phenibut: Dizziness

250 mg 2-3 times a day for 14 days.

Dosage of Phenibut: Motion sickness

250–500 mg 1 hour before the expected onset of a wave rolling or upon the first mild symptoms of seasickness. The effect of Phenibut in such cases builds up with the dosage increase. However, if seasickness signs are severe, e.g. vomiting, the administration of Phenibut is usually ineffective even in doses of 750–1000 mg.

CAUTION: Please note that the recommendations above are not intended as a guide for self-treatment. Even one tablet of Phenibut 250mg may be enough to feel the effects of the compound.  


There are various opinions regarding the dosing schedules on r/Phenibut Reddit community. Generally, nootropic enthusiasts use Phenibut for sleep or anxiety in a dose of up to 1g, once or twice a week. This dose is said to be fine for many people. However, we still recommend avoiding self-treatment and seeking the consultation of a neurologist or another experienced medical professional because even in low dose Phenibut is a very potent medication.

The starter dose with Phenibut is 250mg. That is for the officially produced Phenibut tablets only. Please note that different Phenibut versions may contain different types of isomers in their chemical formula. Officially produced Phenibut tablets usually contain R-isomers which are more potent than S-isomers of some versions which are produced in independent chemical laboratories. Hence S-isomer Phenibut may turn out to be less potent and require larger doses compared with R-isomer Phenibut.     

Phenibut capsules are supposed to be taken orally after meals. The duration of one standard course is not more than 2-3 weeks, upon medical supervision. 


It is not recommended to withdraw from Phenibut abruptly. At the end of the treatment course the dose shall be gradually reduced over a week or two. Otherwise a withdrawal effect may develop.

Phenibut withdrawal varies in severity, and it’s crucial to note that patients abstaining from Phenibut may experience worsening symptoms early on.


According to the instructions, Phenibut 250mg tablets can be used to treat adolescents, children from 3 y.o., and adults. It is also considered to be an effective treatment for senior patients.


Side effects are usually noticeable during the first intakes. Adverse reactions may include sleepiness, nausea, irritability, agitation, anxiety, dizziness, and headache. Allergic reactions are also possible. 


Phenibut overdose can severely depress the central nervous system. It may cause various adverse reactions including aggravation of the side effects listed above. 

If Phenibut is used for a long time in extremely high doses, a hepatotoxic effect, including fatty liver dystrophy, and eosinophilia may arise. 

In case of overdose, instructions recommend gastric lavage, symptomatic treatment, and supportive therapy.


You might have read a lot of scary stories about using Phenibut nootropic. In America, it is reported to be terribly addictive because of misuse or the use of alternative forms of Phenibut, powder for example. 

However, Phenibut is initially and primarily a pharmaceutical drug. It was developed in the Soviet Union in the 1960s as a preparation intended to treat a wide variety of conditions. It was even added to the Russian astronauts’ medical kit 🚀

It helped cosmonauts to decrease stress and also allowed them to maintain high-performance levels, unlike usual tranquilizers. It is a known fact that the cosmonauts of the Soyuz-Apollo Test Project had Phenibut in their medical kits! So in Russia, Phenibut tablets have a history of therapeutic use and people rarely abuse it.

Phenibut is commonly used after consulting a proper specialist. It means that the drug dosage is usually determined by the doctor depending on the diagnosis and personal health indicators of the patient. In Russia, Phenibut is even prescribed to children and elderly people for better sleep, and to women for reducing premenstrual syndrome manifestations, etc. 

Phenibut Review Organika Package

Russian users say that it helps to reduce anxiety, improve sleep, and deal with stress and depression. They also notice that Phenibut can be effective in eliminating some negative effects of other nootropic drugs. So, the picture looks totally different compared to the USA. On average, the experience of using the preparation is much more positive. Although dosing shall be careful. 

In general the difference between the Russian and American versions of Phenibut lies mainly in the dosage. In the countries of its official production, one pill of Phenibut contains 250 mg of the active substance, which is deemed enough for the treatment of many conditions related to the nervous system. For some reason, in the US such a “low” dose is rarely an option.


Phenibut “low” dose, under 1g, is typically used as a cognitive and lifestyle supplement. That is how Phenibut tablets are commonly used in Russia and other countries where it has a licensed production. 

On the other hand, high doses or prolonged administration are sometimes used to get a feeling of Phenibut high or euphoria. According to Phenibut psychonaut, it is reported to be subjectively similar to GHB, alcohol, and certain benzodiazepines.

Phenibut stacks with other psycho-altering substances usually intensify their cumulative effects. The use of such mixes poses a risk of an overdose with many negative consequences, up to the fatal case. You shall also remember that when combining Phenibut with other drugs, the withdrawal syndrome is significantly increased.


For many people who have taken Phenibut supplement for therapeutic purposes but failed to follow the doctor’s recommendations, it turned out to be addictive.

This phenomenon is due to the fact that when the substance enters the body, it inhibits the natural production of compounds responsible for the transmission of nerve impulses through neurons, but the body still needs them. And while standard amounts are not enough, administration of larger doses leads to further build-up of Phenibut tolerance. A snowball effect is observed: the more you take, the greater the dependence becomes. 

Addiction usually develops in the following cases:

  • Use of Phenibut continuously for a long period of time;
  • Exceeding the standard daily dose of 500-1000 mg;
  • Abrupt cessation of use, without a gradual decrease in dosage over 7-14 days;
  • Concomitant use with certain medications, particularly sedatives and anticonvulsants;
  • Concomitant use of Phenibut with alcohol.


In this thread on r/Phenibut a user tests different doses of Phenibut starting from 250mg and up to 1.5g. The effects range significantly: from mild anti-anxiety and better sleep to dizziness, nausea and amnesia with high doses. Eventually, the person chooses Phenibut 500mg daily to treat GAD, bipolar, and ADD. 

And this is an experience of a person with low-dose Phenibut for 3-4 weeks, which reportedly improved sleep, increased libido and relieved anxiety. 

There are also many first-time user experiences. For example, this one was with 1g of Phenibut for recreational purposes. It helped to improve social skills and reduce social anxiety. 

Quite often people mix Phenibut and alcohol, even though the official instructions recommend against it. 


To tell the truth, it is not always a good idea to take Phenibut. First of all, it is a very strong medication that shall only be used when prescribed. If you are new to nootropics it is always better to try something more gentle and mild first. For example Selank, Afobazole, Mexidol, etc.

And second of all, there are a variety of forms, including Phenibut HCL (hydrochloride) and Phenibut FAA (free amino acid). Phenibut HCL is widely available and is used mainly in powder form to be dissolved in a liquid. Phenibut FAA is also a tailor-made Phenibut powder that is often put under the tongue. 

However, these forms, unlike conventional Phenibut tablets, are not used officially in any country for medical treatment. Still, their recreational effects are reported to be very potent. This variety of forms can easily confuse inexperienced nootropic enthusiasts. So it is important to choose the vendor very carefully! 


Phenibut can be legally obtained upon prescription in Russia and some of the CIS countries. In many other countries of Asia and the Middle East, as well as in the USA and the EU, it is a non-scheduled compound that can be easily bought online for example at CosmicNootropic. 

However, if you are from Australia, we highly recommend that you refrain from purchasing Phenibut. In Australia, it is a controlled substance. Hence it will likely be stopped by customs.


If you want to order Phenibut, make sure you trust the source. CosmicNootropic is a trustworthy nootropics vendor that sells original Phenibut only. While many suppliers are facing Phenibut shortage now, our phenibut capsules are in stock at CosmicNootropic.

We offer Phenibut that is officially produced in at least four countries: Russia, Latvia, Belarus, and Ukraine. The list of official manufacturers includes the following pharmaceutical companies: Organika, OlainFarm, OZON, etc. Phenibut undergoes all the necessary drug tests and it is verified for product purity by the manufacturer.


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  1. I Lapin (2001) Phenibut (beta-phenyl-GABA): a tranquilizer and nootropic drug
  2. G Shul’gina, E Ziablitseva (2005) Effect of the GABA derivative phenibut on learning
  3. E Ziablitseva, I Pavlova (2007) Effect of GABA receptor agonist phenibut on behavior and respiration of rabbits in the negative emotional situation
  4. E Zyablitseva, I Pavlova (2008) Effects of the GABA receptor agonist phenibut on behavior and respiration in rabbits in emotionally negative situations
  5. Dambrova et al (2008) Comparative pharmacological activity of optical isomers of phenibut
  6. Ziablitseva et al (2009) The effects of agonists of ionotropic GABA(A) and metabotropic GABA(B) receptors on learning
  7. E Ziablitseva, I Pavlova (2009) Influence of GABA agonist phenibut on the neuronal activity and interaction in hippocampus and neocortex in emotionally negative situations
  8. Borodkina et al (2009) Effect of phenibut on the content of monoamines, their metabolites, and neurotransmitter amino acids in rat brain structures
  9. Tiurenkov et al (2012) Fenibut and its citrate prevent psychoneurological disorders caused by chronic stress (paradoxical sleep deprivation)
  10. Samokhvalov et al (2013) Phenibut dependence
  11. Owen et al (2016) Phenibut (4-amino-3-phenyl-butyric acid): Availability, prevalence of use, desired effects and acute toxicity
  12. Volotova et al (2016) Neuroprotective action of phenibut and neuroglutam in experimental cerebral ischemia on the background of altered immunoreactivity
  13. Vavers et al (2016) The neuroprotective effects of R-phenibut after focal cerebral ischemia
  14. M. V. Velikopolskaya et al (2016). Pharmacokinetic And Pharmacodynamic Properties Of Drugs, Gaba Derivatives Developed In Volgsmu.
  15. Vorob’eva OV, Rusaya VV (2016). Pharmacotherapy of anxiety disorders in patients with chronic cerebral ischemia.
  16. Ahuja et al (2018) Phenibut (β-Phenyl-γ-aminobutyric Acid) Dependence and Management of Withdrawal: Emerging Nootropics of Abuse
  17. Joshi et al (2018) Dissociative intoxication and prolonged withdrawal associated with phenibut: a case report
  18. Ryan Feldman, Brian Autry, Joanna Dukes, Thomas Lofy, Gina Marchetti, Amber Patt,Nicole Batterman, Jillian Theobald (2023) A systematic review of phenibut withdrawal focusing on complications, therapeutic approaches, and single substance versus polysubstance withdrawal

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