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{{SubstanceBox/Phenibut}}
{{SubstanceBox/Phenibut}}


'''β-Phenyl-γ-aminobutyric acid''' (also known as '''Fenibut''', '''Phenybut''', '''Noofen''', '''Citrocard''', and commonly as '''Phenibut''') is a lesser-known [[psychoactive class::depressant]] substance of the [[chemical class::gabapentinoid]] class.<ref name="six">Elaine Wyllie; Gregory D. Cascino; Barry E. Gidal; Howard P. Goodkin (17 February 2012). Wyllie's Treatment of Epilepsy: Principles and Practice. Lippincott Williams & Wilkins. p. 423. | https://books.google.co.uk/books?id=j9t6Qg0kkuUC&pg=RA1-PA423&redir_esc=y#v=onepage&q&f=false</ref><ref name="seven">Honorio Benzon; James P. Rathmell; Christopher L. Wu; Dennis C. Turk; Charles E. Argoff; Robert W Hurley (11 September 2013). Practical Management of Pain. Elsevier Health Sciences. p. 1006. | https://books.google.co.uk/books?id=kfcDAQAAQBAJ&pg=PA1006&redir_esc=y#v=onepage&q&f=false</ref>  
'''β-Phenyl-γ-aminobutyric acid''' (also known as '''Fenibut''', '''Phenybut''', '''Noofen''', '''Citrocard''', and commonly as '''Phenibut''') is a lesser-known [[psychoactive class::depressant]] substance of the [[chemical class::gabapentinoid]] class.<ref name="six">{{cite book | vauthors=((Wyllie, E.)), ((Cascino, G. D.)), ((Gidal, B. E.)), ((Goodkin, H. P.)) | date=17 February 2012 | title=Wyllie’s Treatment of Epilepsy: Principles and Practice | publisher=Lippincott Williams & Wilkins | isbn=9781451153484}}</ref><ref name="seven">{{cite book | vauthors=((Benzon, H.)), ((Rathmell, J. P.)), ((Wu, C. L.)), ((Turk, D.)), ((Argoff, C. E.)), ((Hurley, R. W.)) | date=11 September 2013 | title=Practical Management of Pain E-Book | publisher=Elsevier Health Sciences | isbn=9780323170802}}</ref>  
Phenibut acts as a [[receptor]] [[agonist]] for [[GABA]], the major inhibitory [[neurotransmitter]] in the brain.  
Phenibut acts as a [[receptor]] [[agonist]] for [[GABA]], the major inhibitory [[neurotransmitter]] in the brain.  
It is chemically related to [[baclofen]], [[pregabalin]], and [[gabapentin]].<ref name="one">Lapin, I. (2001). "Phenibut (beta-phenyl-GABA): A tranquilizer and nootropic drug" (pdf). CNS Drug Reviews | http://onlinelibrary.wiley.com/doi/10.1111/j.1527-3458.2001.tb00211.x/pdf</ref>
It is chemically related to [[baclofen]], [[pregabalin]], and [[gabapentin]].<ref name="one">{{cite journal | vauthors=((Lapin, I.)) | journal=CNS Drug Reviews | title=Phenibut (β-Phenyl-GABA): A Tranquilizer and Nootropic Drug | volume=7 | issue=4 | pages=471–481 | date=7 June 2006 | url=https://onlinelibrary.wiley.com/doi/10.1111/j.1527-3458.2001.tb00211.x | issn=1080563X | doi=10.1111/j.1527-3458.2001.tb00211.x}}</ref>


Phenibut was developed in the Soviet Union in the 1960s, where it has been used as a pharmaceutical drug to treat a wide variety of conditions, including post-traumatic stress disorder, anxiety, depression, asthenia, insomnia, alcoholism, stuttering, and vestibular disorders, and others.<ref name="two">Shulgina, G. I. (1986). "On neurotransmitter mechanisms of reinforcement and internal inhibition". The Pavlovian journal of biological science (PubMed.gov / NCBI) | https://www.ncbi.nlm.nih.gov/pubmed/2431377</ref><ref name="three">David W. Group (25 February 2015). Encyclopedia of Mind Enhancing Foods, Drugs and Nutritional Substances, 2d ed. McFarland. pp. 186–. | https://books.google.co.uk/books?id=ZYqoBgAAQBAJ&pg=PA186&hl=en#v=onepage&q&f=false</ref><ref name="one" /> In the rest of the world, phenibut is not approved for clinical use and is instead sold as a nutritional supplement.  
Phenibut was developed in the Soviet Union in the 1960s, where it has been used as a pharmaceutical drug to treat a wide variety of conditions, including post-traumatic stress disorder, anxiety, depression, asthenia, insomnia, alcoholism, stuttering, and vestibular disorders, and others.<ref name="two">{{cite journal | vauthors=((Shulgina, G. I.)) | journal=The Pavlovian Journal of Biological Science | title=On neurotransmitter mechanisms of reinforcement and internal inhibition | volume=21 | issue=4 | pages=129–140 | date= December 1986 | issn=0093-2213 | doi=10.1007/BF02734511}}</ref><ref name="three">{{cite book | vauthors=((Group, D. W.)) | date=25 February 2015 | title=Encyclopedia of Mind Enhancing Foods, Drugs and Nutritional Substances, 2d ed. | publisher=McFarland | isbn=9780786441426}}</ref><ref name="one" /> In the rest of the world, phenibut is not approved for clinical use and is instead sold as a nutritional supplement.  


[[Subjective effects]] include [[anxiety suppression]], [[sedation]], [[muscle relaxation]], [[motivation enhancement|enhanced motivation]], and [[euphoria]]. Lower doses (under 1 gram) are typically used as a cognitive and lifestyle supplement while higher doses are used for a recreational high that is reported to be subjectively similar to [[GHB]], [[alcohol]], and certain [[benzodiazepines]].  
[[Subjective effects]] include [[anxiety suppression]], [[sedation]], [[muscle relaxation]], [[motivation enhancement|enhanced motivation]], and [[euphoria]]. Lower doses (under 1 gram) are typically used as a cognitive and lifestyle supplement while higher doses are used for a recreational high that is reported to be subjectively similar to [[GHB]], [[alcohol]], and certain [[benzodiazepines]].  


Although phenibut is commonly marketed as a [[nootropic]] by retailers, evidence that it enhances cognition is limited. It is generally accepted that phenibut has anxiolytic effects in both animal and in humans.<ref name="one">Lapin, I. (2001). "Phenibut (beta-phenyl-GABA): A tranquilizer and nootropic drug" (pdf). CNS Drug Reviews | http://onlinelibrary.wiley.com/doi/10.1111/j.1527-3458.2001.tb00211.x/pdf</ref> Due to its habit-forming properties, it is highly advised to use [[harm reduction practices]] if using this substance.
Although phenibut is commonly marketed as a [[nootropic]] by retailers, evidence that it enhances cognition is limited. It is generally accepted that phenibut has anxiolytic effects in both animal and in humans.<ref name="one" /> Due to its habit-forming properties, it is highly advised to use [[harm reduction practices]] if using this substance.


==Chemistry==
==Chemistry==
Phenibut is a derivative of GABA with a phenyl group in the β-position. The addition of a phenyl ring to the GABA molecule allows it to cross the blood-brain barrier and produce psychoactive effects.<ref name="one">Lapin, I. (2001). "Phenibut (beta-phenyl-GABA): A tranquilizer and nootropic drug" (pdf). CNS Drug Reviews | http://onlinelibrary.wiley.com/doi/10.1111/j.1527-3458.2001.tb00211.x/pdf</ref> Phenibut has a near-identical structure as baclofen, lacking only a chlorine atom in the para-position of the phenyl group<ref>Shulgina, G. I. (1986). On neurotransmitter mechanisms of reinforcement and internal inhibition. Integrative Physiological and Behavioral Science, 21(4), 129-140.</ref> and contains phenethylamine in its structure.<ref>https://www.ncbi.nlm.nih.gov/pubmed/11830761</ref> [[Pregabalin]] also has a near-identical structure as phenibut, except it has an isobutyl group instead of a phenyl group.
Phenibut is a derivative of GABA with a phenyl group in the β-position. The addition of a phenyl ring to the GABA molecule allows it to cross the blood-brain barrier and produce psychoactive effects.<ref name="one" /> Phenibut has a near-identical structure as baclofen, lacking only a chlorine atom in the para-position of the phenyl group<ref>{{cite journal | vauthors=((Shulgina, G. I.)) | journal=The Pavlovian Journal of Biological Science | title=On neurotransmitter mechanisms of reinforcement and internal inhibition | volume=21 | issue=4 | pages=129–140 | date= October 1986 | url=https://link.springer.com/10.1007/BF02734511 | issn=0093-2213 | doi=10.1007/BF02734511}}</ref> and contains phenethylamine in its structure.<ref>{{cite journal | vauthors=((Lapin, I.)) | journal=CNS drug reviews | title=Phenibut (beta-phenyl-GABA): a tranquilizer and nootropic drug | volume=7 | issue=4 | pages=471–481 | date= 2001 | issn=1080-563X | doi=10.1111/j.1527-3458.2001.tb00211.x}}</ref> [[Pregabalin]] also has a near-identical structure as phenibut, except it has an isobutyl group instead of a phenyl group.


Phenibut is a chiral molecule and thus has two potential configurations, as (R)- and (S)-enantiomers.<ref>Dambrova, M., Zvejniece, L., Liepinsh, E., Cirule, H., Zharkova, O., Veinberg, G., & Kalvinsh, I. (2008). The comparative pharmacological activity of optical isomers of phenibut. European Journal of Pharmacology, 583(1), 128-134.</ref>
Phenibut is a chiral molecule and thus has two potential configurations, as (R)- and (S)-enantiomers.<ref>{{cite journal | vauthors=((Dambrova, M.)), ((Zvejniece, L.)), ((Liepinsh, E.)), ((Cirule, H.)), ((Zharkova, O.)), ((Veinberg, G.)), ((Kalvinsh, I.)) | journal=European Journal of Pharmacology | title=Comparative pharmacological activity of optical isomers of phenibut | volume=583 | issue=1 | pages=128–134 | date= March 2008 | url=https://linkinghub.elsevier.com/retrieve/pii/S001429990800068X | issn=00142999 | doi=10.1016/j.ejphar.2008.01.015}}</ref>


Most commercial phenibut is reported to be in the form of the hydrochloride salt (HCl). In this form, the phenibut is reacted with hydrochloric acid to form a stable, easily dissolvable, acidic, crystalline salt.
Most commercial phenibut is reported to be in the form of the hydrochloride salt (HCl). In this form, the phenibut is reacted with hydrochloric acid to form a stable, easily dissolvable, acidic, crystalline salt.
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==Pharmacology==
==Pharmacology==
Phenibut has a more complex pharmacological profile than many other [[depressants]].  
Phenibut has a more complex pharmacological profile than many other [[depressants]].  
Unlike [[benzodiazepines]], for example, phenibut acts as a full [[agonist]] of the [[GABA]]<sub>B</sub> [[receptor]], similar to baclofen and high doses of [[GHB]].<ref name="eight">GABAb Receptor Pharmacology: A Tribute to Norman Bowery: A Tribute to Norman Bowery. Academic Press. | https://books.google.co.uk/books?id=_iMDQOA2UIsC&pg=PA25&redir_esc=y#v=onepage&q&f=false</ref> At higher doses, phenibut loses its selectivity of GABA<sub>B</sub>, and gains additional activity as a GABA<sub>A</sub> [[agonist]].<ref name="ZyablitsevaPavlova2010">{{cite journal|last1=Zyablitseva|first1=E. A.|last2=Pavlova|first2=I. V.|title=Effects of the GABA Receptor Agonist Phenibut on Spike Activity and Interactions between Neocortex and Hippocampus Neurons in Emotionally Negative Situations|journal=Neuroscience and Behavioral Physiology|volume=40|issue=9|year=2010|pages=1003–1011|issn=0097-0549|doi=10.1007/s11055-010-9360-y}}</ref>  
Unlike [[benzodiazepines]], for example, phenibut acts as a full [[agonist]] of the [[GABA]]<sub>B</sub> [[receptor]], similar to baclofen and high doses of [[GHB]].<ref name="eight">{{cite book | date=21 September 2010 | title=GABAb Receptor Pharmacology: A Tribute to Norman Bowery | publisher=Academic Press | isbn=9780123786487}}</ref> At higher doses, phenibut loses its selectivity of GABA<sub>B</sub>, and gains additional activity as a GABA<sub>A</sub> [[agonist]].<ref name="ZyablitsevaPavlova2010">{{cite journal|last1=Zyablitseva|first1=E. A.|last2=Pavlova|first2=I. V.|title=Effects of the GABA Receptor Agonist Phenibut on Spike Activity and Interactions between Neocortex and Hippocampus Neurons in Emotionally Negative Situations|journal=Neuroscience and Behavioral Physiology|volume=40|issue=9|year=2010|pages=1003–1011|issn=0097-0549|doi=10.1007/s11055-010-9360-y}}</ref>  
Phenibut's effects at the GABA<sub>B</sub> receptor are responsible for its sedating effects.{{citation needed}}
Phenibut's effects at the GABA<sub>B</sub> receptor are responsible for its sedating effects.{{citation needed}}


Recent research has shown that phenibut binds to and blocks α2δ subunit-containing voltage-dependent calcium channels (VDCCs), similarly to gabapentinoids such as [[gabapentin]]
Recent research has shown that phenibut binds to and blocks α2δ subunit-containing voltage-dependent calcium channels (VDCCs), similarly to gabapentinoids such as [[gabapentin]]
and [[pregabalin]].<ref name="nine" />  
and [[pregabalin]].<ref name="nine" /> Both enantiomers of phenibut show this action with similar efficacy. The R-enantiomer possesses five-fold greater affinity for α2δ subunit-containing voltage-gated calcium channels relative to the GABA<sub>B</sub> receptor, whereas the S-entantiomer does not have any efficacy at the GABA<sub>B</sub> receptor.<ref name="nine">{{cite journal | vauthors=((Dambrova, M.)), ((Zvejniece, L.)), ((Liepinsh, E.)), ((Cirule, H.)), ((Zharkova, O.)), ((Veinberg, G.)), ((Kalvinsh, I.)) | journal=European Journal of Pharmacology | title=Comparative pharmacological activity of optical isomers of phenibut | volume=583 | issue=1 | pages=128–134 | date=31 March 2008 | issn=0014-2999 | doi=10.1016/j.ejphar.2008.01.015}}</ref>
Both enantiomers of phenibut show this action with similar efficacy.  
 
The R-enantiomer possesses five-fold greater affinity for α2δ subunit-containing voltage-gated calcium channels relative to the GABA<sub>B</sub> receptor, whereas the S-entantiomer does not have any efficacy at the GABA<sub>B</sub> receptor.<ref name="nine">Dambrova, M.; Zvejniece, L.; Liepinsh, E.; Cirule, H.; Zharkova, O.; Veinberg, G.; Kalvinsh, I. (2008). "Comparative pharmacological activity of optical isomers of phenibut". European Journal of Pharmacology (PubMed.gov / NCBI) | https://www.ncbi.nlm.nih.gov/pubmed/18275958</ref>
The [[pain relief|analgesic]] effects of phenibut in rodents are not mediated by the GABA<sub>B</sub> receptor but by the blockage of α2δ subunit-containing voltage-gated calcium channels.<ref name="nine" />
The [[pain relief|analgesic]] effects of phenibut in rodents are not mediated by the GABA<sub>B</sub> receptor but by the blockage of α2δ subunit-containing voltage-gated calcium channels.<ref name="nine" />


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}}
}}
|{{effects/cognitive|
|{{effects/cognitive|
*'''[[Effect::Anxiety suppression]]''' - Phenibut has medium to strong anxiolytic effects, although generally less powerful than [[benzodiazepines]].
*'''[[Effect::Anxiety suppression]]''' - Phenibut has medium to strong anxiolytic effects, equivalent to alcohol but generally less powerful than [[benzodiazepines]].
*'''[[Effect::Disinhibition]]''' - Phenibut has strong disinhibiting effects comparable to that of higher doses of [[alcohol]], [[benzodiazepines]], or [[GHB]].
*'''[[Effect::Disinhibition]]''' - Phenibut has strong disinhibiting effects comparable to that of higher doses of [[alcohol]], [[benzodiazepines]], or [[GHB]].
*'''[[Effect::Cognitive euphoria]]''' - This effect is more pronounced than that of [[alcohol]] and [[benzodiazepines]], most likely due to more clear-headed and stimulative nature of phenibut.
*'''[[Effect::Cognitive euphoria]]''' - This effect is more pronounced than that of [[alcohol]] and [[benzodiazepines]], most likely due to more clear-headed and stimulative nature of phenibut.
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==Toxicity and harm potential==
==Toxicity and harm potential==
{{toxicity}}
Phenibut has a [[Toxicity::low toxicity]] relative to dose. However, it is [[Toxicity::potentially [[respiratory depression|lethal]] when mixed with [[depressants]] like [[alcohol]], [[benzodiazepines]] or [[opioids]]]].
Phenibut has a [[Toxicity::low toxicity]] relative to dose. However, it is [[Toxicity::potentially [[respiratory depression|lethal]] when mixed with [[depressants]] like [[alcohol]], [[benzodiazepines]] or [[opioids]]]].


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It is strongly recommended that one use [[responsible drug use|harm reduction practices]] when using this substance.
It is strongly recommended that one use [[responsible drug use|harm reduction practices]] when using this substance.


===Tolerance and addiction potential===
===Dependence and abuse potential===
Phenibut is [[Addiction potential::moderately physically and psychologically addictive]], although this usually only occurs with heavy abuse of the substance.
Phenibut is [[Addiction potential::moderately physically and psychologically addictive]], although this usually only occurs with heavy abuse of the substance.


Tolerance will develop to the sedative-hypnotic effects [[Time to full tolerance::within a couple of days of continuous use]].  
Tolerance will develop to the sedative-hypnotic effects [[Time to full tolerance::within a couple of days of continuous use]].  
After cessation, the tolerance returns to baseline in [[Time to zero tolerance::7 - 14 days]].  
After cessation, the tolerance returns to baseline in [[Time to zero tolerance::7 - 14 days]].  
Withdrawal symptoms or rebound symptoms may occur after ceasing usage abruptly following a few weeks or longer of steady dosing and may necessitate a gradual dose reduction. Withdrawal symptoms include severe [[anxiety]], nervousness, hallucinations, tremors, agitation, [[dizziness]], tension, irritation, [[increased heart rate|rapid heartbeat]], [[physical fatigue|fatigue]], [[appetite suppression|loss of appetite]], [[nausea]], vomiting, [[psychosis]], and [[insomnia]].<ref name="three">David W. Group (25 February 2015). Encyclopedia of Mind Enhancing Foods, Drugs and Nutritional Substances, 2d ed. McFarland. pp. 186–. | https://books.google.co.uk/books?id=ZYqoBgAAQBAJ&pg=PA186&hl=en#v=onepage&q&f=false</ref>
Withdrawal symptoms or rebound symptoms may occur after ceasing usage abruptly following a few weeks or longer of steady dosing and may necessitate a gradual dose reduction. Withdrawal symptoms include severe [[anxiety]], nervousness, hallucinations, tremors, agitation, [[dizziness]], tension, irritation, [[increased heart rate|rapid heartbeat]], [[physical fatigue|fatigue]], [[appetite suppression|loss of appetite]], [[nausea]], vomiting, [[psychosis]], and [[insomnia]].<ref name="three" />


Phenibut produces cross-tolerance with [[Cross-tolerance::all [[GABA]]genic depressants]], meaning that after its consumption, depressants will have a reduced effect.
Phenibut produces cross-tolerance with [[Cross-tolerance::all [[GABA]]genic depressants]], meaning that after its consumption, depressants will have a reduced effect.
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{{DangerousInteractions/Intro}}
{{DangerousInteractions/Intro}}


*'''[[Depressants]]''' (''[[1,4-Butanediol]], [[2M2B]], [[alcohol]],<ref>Koski, A., Ojanperä, I., & Vuori, E. (2002). Alcohol and benzodiazepines in fatal poisonings. Alcoholism: Clinical and Experimental Research, 26(7), 956-959.</ref> [[benzodiazepines]], [[barbiturates]], [[GHB]]/[[GBL]], [[methaqualone]], [[opioids]]'') - This combination can result in dangerous or even fatal levels of [[respiratory depression]]. These substances potentiate the [[muscle relaxation]], [[sedation]] and [[amnesia]] caused by one another and can lead to unexpected loss of consciousness at high doses. There is also an increased risk of vomiting during unconsciousness and death from the resulting suffocation. If this occurs, users should attempt to fall asleep in the [[recovery position]] or have a friend move them into it.
*'''[[Depressants]]''' (''[[1,4-Butanediol]], [[2M2B]], [[alcohol]],<ref>{{cite journal | vauthors=((Koski, A.)), ((Ojanpera, I.)), ((Vuori, E.)) | journal=Alcoholism: Clinical and Experimental Research | title=Alcohol and Benzodiazepines in Fatal Poisonings | volume=26 | issue=7 | pages=956–959 | date= July 2002 | url=https://onlinelibrary.wiley.com/doi/10.1111/j.1530-0277.2002.tb02627.x | issn=0145-6008 | doi=10.1111/j.1530-0277.2002.tb02627.x}}</ref> [[benzodiazepines]], [[barbiturates]], [[GHB]]/[[GBL]], [[methaqualone]], [[opioids]]'') - This combination can result in dangerous or even fatal levels of [[respiratory depression]]. These substances potentiate the [[muscle relaxation]], [[sedation]] and [[amnesia]] caused by one another and can lead to unexpected loss of consciousness at high doses. There is also an increased risk of vomiting during unconsciousness and death from the resulting suffocation. If this occurs, users should attempt to fall asleep in the [[recovery position]] or have a friend move them into it.
*'''[[Dissociatives]]''' - This combination can result in an increased risk of vomiting during unconsciousness and death from the resulting suffocation. If a sudden loss of consciousness occurs, users should attempt to fall asleep in the [[recovery position]] or have a friend move them into it.
*'''[[Dissociatives]]''' - This combination can result in an increased risk of vomiting during unconsciousness and death from the resulting suffocation. If a sudden loss of consciousness occurs, users should attempt to fall asleep in the [[recovery position]] or have a friend move them into it.
*'''[[Stimulants]]''' -  Phenibut is reported to enhance the positive effects of [[stimulants]] as well as reduce jitteriness and anxiety.<ref>https://thedrugclassroom.com/video/phenibut/ The Drug Classroom - Phenibut: Combinations</ref> However, this combination can be dangerous due to the risk of excessive intoxication. Stimulants mask the [[sedation|sedative]] effects of phenibut; once the stimulant wears off, the depressant effects of phenibut will be significantly increased, leading to intensified [[disinhibition]] as well as [[Phenibut#Subjective effects|other effects]]. If combined, one should strictly limit themselves to a certain dose of phenibut prior to stimulant consumption and not redose. This combination can also potentially result in significant dehydration.
*'''[[Stimulants]]''' -  Phenibut is reported to enhance the positive effects of [[stimulants]] as well as reduce jitteriness and anxiety.<ref>{{Citation | title=The Drug Classroom - Phenibut: Combinations | url=https://thedrugclassroom.com/video/phenibut/}}</ref> However, this combination can be dangerous due to the risk of excessive intoxication. Stimulants mask the [[sedation|sedative]] effects of phenibut; once the stimulant wears off, the depressant effects of phenibut will be significantly increased, leading to intensified [[disinhibition]] as well as [[Phenibut#Subjective effects|other effects]]. If combined, one should strictly limit themselves to a certain dose of phenibut prior to stimulant consumption and not redose. This combination can also potentially result in significant dehydration.


==Legal status==
==Legal status==


*'''Australia:''' Phenibut is a schedule 9 substance in Australia as of February 1st 2018, meaning it is illegal to possess, import, supply or manufacture.{{citation needed}}
*'''Australia''': Phenibut is a schedule 9 substance in Australia as of February 1st 2018, meaning it is illegal to possess, import, supply or manufacture.{{citation needed}}
*'''Canada:''' Phenibut is not a controlled substance in Canada, meaning it is legal to possess without any sort of license or prescription. {{citation needed}}
*'''Canada''': Phenibut is not a controlled substance in Canada, meaning it is legal to possess without any sort of license or prescription. {{citation needed}}
*'''Germany:''' Phenibut is not a controlled substance under the BtMG.<ref>http://www.gesetze-im-internet.de/btmg_1981/anlage_i.html</ref> It is legal, as long as it is not sold for human consumption, according to §2 AMG.<ref>https://www.gesetze-im-internet.de/amg_1976/__2.html</ref>
*'''Germany''': Phenibut may be controlled under the NpSG (''New Psychoactive Substances Act'')<ref>{{cite web|url=https://www.gesetze-im-internet.de/npsg/anlage.html|title=Anlage NpSG|publisher=Bundesministerium der Justiz und für Verbraucherschutz|access-date=December 10, 2019|language=de}}</ref> as of July 18, 2019. <ref>{{cite web|url=http://www.bgbl.de/xaver/bgbl/start.xav?startbk=Bundesanzeiger_BGBl&jumpTo=bgbl119s1083.pdf|title=Verordnung zur Änderung der Anlage des Neue-psychoaktive-Stoffe-Gesetzes und von Anlagen des Betäubungsmittelgesetzes|publisher=Bundesanzeiger Verlag|access-date=December 28, 2019|work=Bundesgesetzblatt Jahrgang 2019 Teil I|publication-date=July 17, 2019|language=de}}</ref> If this law applies to Phenibut remains unclear.<ref>{{cite web|url=https://www.gesetze-im-internet.de/npsg/__4.html|title=§ 4 NpSG|publisher=Bundesministerium der Justiz und für Verbraucherschutz|access-date=December 10, 2019|language=de}}</ref><ref>[https://www.ift.de/fileadmin/user_upload/Literatur/Berichte/Kraus_et_al_2020_NpSG-Abschlussbericht.pdf ''Evaluation der Auswirkungen des Neue-psychoaktive-Stoffe-Gesetzes  (NpSG): Abschlussbericht.'']</ref>
*'''Italy''': Phenibut is a Schedule 1 controlled substance.<ref>[http://www.salute.gov.it/imgs/C_17_pagineAree_3729_0_file.pdf Tabella 1](PDF) (in Italian). Ministero della Salute [Ministry of Health]. p.19. Retrieved November 24, 2020.</ref>
*'''Latvia''': Phenibut is an unscheduled prescription drug, marketed as "Noofen".<ref>https://dati.zva.gov.lv/zalu-registrs/?iss=1&q=Phenibutum Database of licensed phenibut medicines and their legal status under the State Agency of Medicines of the Republic of Latvia. ''Retrieved August 26, 2023.''</ref><ref>https://likumi.lv/ta/en/en/id/50539 Active Latvian law regarding scheduled and banned substances. ''Retrieved August 26, 2023.''</ref>
*'''Switzerland''': Phenibut is not controlled under Buchstabe A, B, C and D. It could be considered legal.<ref>{{cite web|url=https://www.admin.ch/opc/de/classified-compilation/20101220/index.html|title=Verordnung des EDI über die Verzeichnisse der Betäubungsmittel, psychotropen Stoffe, Vorläuferstoffe und Hilfschemikalien|publisher=Bundeskanzlei [Federal Chancellery of Switzerland]|access-date=January 1, 2020|language=de}}</ref>
*'''Switzerland''': Phenibut is not controlled under Buchstabe A, B, C and D. It could be considered legal.<ref>{{cite web|url=https://www.admin.ch/opc/de/classified-compilation/20101220/index.html|title=Verordnung des EDI über die Verzeichnisse der Betäubungsmittel, psychotropen Stoffe, Vorläuferstoffe und Hilfschemikalien|publisher=Bundeskanzlei [Federal Chancellery of Switzerland]|access-date=January 1, 2020|language=de}}</ref>
*'''United Kingdom:''' Phenibut is not a controlled substance in the United Kingdom. It'' may'' be illegal to produce, supply, or import this drug under the Psychoactive Substance Act 2016, which applies a blanket restriction on all "psychoactive substances" with exemptions for alcohol, nicotine and "medicinal products".<ref>Psychoactive Substances Act 2016 (Legislation.gov.uk) | http://www.legislation.gov.uk/ukpga/2016/2/contents/enacted</ref>
*'''United Kingdom''': Phenibut is not a controlled substance in the United Kingdom. It'' may'' be illegal to produce, supply, or import this drug under the Psychoactive Substance Act 2016, which applies a blanket restriction on all "psychoactive substances" with exemptions for alcohol, nicotine and "medicinal products".<ref>{{Citation | title=Psychoactive Substances Act 2016 | url=https://www.legislation.gov.uk/ukpga/2016/2/contents/enacted}}</ref>
*'''United States:''' Phenibut is not a controlled substance in the United States, meaning it is legal to possess without any sort of license or prescription.<ref name="eleven">Phenibut Legal Status by Erowid | https://erowid.org/smarts/phenibut/phenibut_law.shtml</ref>
*'''United States''': Phenibut is not a controlled substance in the United States, meaning it is federally legal to possess without any sort of license or prescription.<ref name="eleven">{{Citation | title=Erowid Phenibut Vault: Legal Status | url=https://erowid.org/smarts/phenibut/phenibut_law.shtml}}</ref>Phenibut is a Schedule II controlled substance in Alabama as of November 21st, 2021.<ref>Alabama List of Controlled Substances<nowiki/>https://www.alabamapublichealth.gov/blog/assets/controlledsubstanceslist.pdf</ref>
*'''Italy''': Phenibut is a Schedule 1 controlled substance.<ref>[http://www.salute.gov.it/imgs/C_17_pagineAree_3729_0_file.pdf Tabella 1](PDF) (in Italian). Ministero della Salute [Ministry of Health]. p.19. Retrieved November 24, 2020.</ref>


==See also==
==See also==

Latest revision as of 23:35, 12 June 2025

Fatal overdose may occur when gabapentinoids are combined with other depressants such as opiates, benzodiazepines, barbiturates, thienodiazepines, alcohol or other GABAergic substances.[1]

It is strongly discouraged to combine these substances, particularly in common to heavy doses.

Summary sheet: Phenibut
Phenibut
Chemical Nomenclature
Common names Phenibut, Fenibut, Phenybut, PhGABA
Substitutive name β-Phenyl-γ-aminobutyric acid
Systematic name (RS)-4-Amino-3-phenyl-butyric acid
Class Membership
Psychoactive class Depressant
Chemical class Gabapentinoid
Routes of Administration

WARNING: Always start with lower doses due to differences between individual body weight, tolerance, metabolism, and personal sensitivity. See responsible use section.



Oral
Dosage
Threshold 0.25 g
Light 0.5 - 1 g
Common 1 - 2 g
Strong 2 - 3.5 g
Heavy 3.5 g +
Duration
Total 10 - 16 hours
Onset 1.5 - 3 hours
Come up 1.5 - 3 hours
Peak 3 - 4 hours
Offset 4 - 6 hours
After effects 6 - 24 hours









DISCLAIMER: PW's dosage information is gathered from users and resources for educational purposes only. It is not a recommendation and should be verified with other sources for accuracy.

Interactions


β-Phenyl-γ-aminobutyric acid (also known as Fenibut, Phenybut, Noofen, Citrocard, and commonly as Phenibut) is a lesser-known depressant substance of the gabapentinoid class.[2][3] Phenibut acts as a receptor agonist for GABA, the major inhibitory neurotransmitter in the brain. It is chemically related to baclofen, pregabalin, and gabapentin.[4]

Phenibut was developed in the Soviet Union in the 1960s, where it has been used as a pharmaceutical drug to treat a wide variety of conditions, including post-traumatic stress disorder, anxiety, depression, asthenia, insomnia, alcoholism, stuttering, and vestibular disorders, and others.[5][6][4] In the rest of the world, phenibut is not approved for clinical use and is instead sold as a nutritional supplement.

Subjective effects include anxiety suppression, sedation, muscle relaxation, enhanced motivation, and euphoria. Lower doses (under 1 gram) are typically used as a cognitive and lifestyle supplement while higher doses are used for a recreational high that is reported to be subjectively similar to GHB, alcohol, and certain benzodiazepines.

Although phenibut is commonly marketed as a nootropic by retailers, evidence that it enhances cognition is limited. It is generally accepted that phenibut has anxiolytic effects in both animal and in humans.[4] Due to its habit-forming properties, it is highly advised to use harm reduction practices if using this substance.

Chemistry

Phenibut is a derivative of GABA with a phenyl group in the β-position. The addition of a phenyl ring to the GABA molecule allows it to cross the blood-brain barrier and produce psychoactive effects.[4] Phenibut has a near-identical structure as baclofen, lacking only a chlorine atom in the para-position of the phenyl group[7] and contains phenethylamine in its structure.[8] Pregabalin also has a near-identical structure as phenibut, except it has an isobutyl group instead of a phenyl group.

Phenibut is a chiral molecule and thus has two potential configurations, as (R)- and (S)-enantiomers.[9]

Most commercial phenibut is reported to be in the form of the hydrochloride salt (HCl). In this form, the phenibut is reacted with hydrochloric acid to form a stable, easily dissolvable, acidic, crystalline salt.

Alternatively, phenibut can exist as a free amino acid (FAA). In this form, phenibut is close to pH neutral, non-crystalline, slow to dissolve and mildly bitter. The FAA form has about 20% more phenibut molecules on an equal mass basis compared to phenibut HCl. Phenibut FAA has the advantage of being suitable for sublingual, rectal, or intranasal use, which can be more efficient, faster-acting, and predictable for some. Phenibut FAA is converted to phenibut HCl in the stomach. Equal masses of the two forms will have roughly equivalent effects when taken the same way (FAA may be slightly stronger).

Pharmacology

Phenibut has a more complex pharmacological profile than many other depressants. Unlike benzodiazepines, for example, phenibut acts as a full agonist of the GABAB receptor, similar to baclofen and high doses of GHB.[10] At higher doses, phenibut loses its selectivity of GABAB, and gains additional activity as a GABAA agonist.[11] Phenibut's effects at the GABAB receptor are responsible for its sedating effects.[citation needed]

Recent research has shown that phenibut binds to and blocks α2δ subunit-containing voltage-dependent calcium channels (VDCCs), similarly to gabapentinoids such as gabapentin and pregabalin.[12] Both enantiomers of phenibut show this action with similar efficacy. The R-enantiomer possesses five-fold greater affinity for α2δ subunit-containing voltage-gated calcium channels relative to the GABAB receptor, whereas the S-entantiomer does not have any efficacy at the GABAB receptor.[12]

The analgesic effects of phenibut in rodents are not mediated by the GABAB receptor but by the blockage of α2δ subunit-containing voltage-gated calcium channels.[12]

Subjective effects

In comparison to other commonly used GABAergic depressants such as alcohol or benzodiazepines, phenibut is reported to be longer-lasting, more euphoric and more recreational at higher doses.

Disclaimer: The effects listed below cite the Subjective Effect Index (SEI), an open research literature based on anecdotal user reports and the personal analyses of PsychonautWiki contributors. As a result, they should be viewed with a healthy degree of skepticism.

It is also worth noting that these effects will not necessarily occur in a predictable or reliable manner, although higher doses are more liable to induce the full spectrum of effects. Likewise, adverse effects become increasingly likely with higher doses and may include addiction, severe injury, or death ☠.

Physical effects

Visual effects

Cognitive effects

After effects

Experience reports

There are currently 2 experience reports which describe the effects of this compound in our experience index.

Additional experience reports can be found here:

Toxicity and harm potential

This toxicity and harm potential section is a stub.

As a result, it may contain incomplete or even dangerously wrong information! You can help by expanding upon or correcting it.
Note: Always conduct independent research and use harm reduction practices if using this substance.

Phenibut has a low toxicity relative to dose. However, it is [[Toxicity::potentially lethal when mixed with depressants like alcohol, benzodiazepines or opioids]].

Phenibut hydrochloride is highly caustic and in sensitive users can cause intestinal discomfort and diarrhea with some lower digestive tract bleeding.[citation needed]

Due to the extremely long come up period relative to other substances, some users may experience an urge to redose out of the belief that it is weak or not working. This should be avoided to prevent overdose.

It is strongly recommended that one use harm reduction practices when using this substance.

Dependence and abuse potential

Phenibut is moderately physically and psychologically addictive, although this usually only occurs with heavy abuse of the substance.

Tolerance will develop to the sedative-hypnotic effects within a couple of days of continuous use. After cessation, the tolerance returns to baseline in 7 - 14 days. Withdrawal symptoms or rebound symptoms may occur after ceasing usage abruptly following a few weeks or longer of steady dosing and may necessitate a gradual dose reduction. Withdrawal symptoms include severe anxiety, nervousness, hallucinations, tremors, agitation, dizziness, tension, irritation, rapid heartbeat, fatigue, loss of appetite, nausea, vomiting, psychosis, and insomnia.[6]

Phenibut produces cross-tolerance with [[Cross-tolerance::all GABAgenic depressants]], meaning that after its consumption, depressants will have a reduced effect.

Dangerous interactions

Warning: Many psychoactive substances that are reasonably safe to use on their own can suddenly become dangerous and even life-threatening when combined with certain other substances. The following list provides some known dangerous interactions (although it is not guaranteed to include all of them).

Always conduct independent research (e.g. Google, DuckDuckGo, PubMed) to ensure that a combination of two or more substances is safe to consume. Some of the listed interactions have been sourced from TripSit.

  • Depressants (1,4-Butanediol, 2M2B, alcohol,[13] benzodiazepines, barbiturates, GHB/GBL, methaqualone, opioids) - This combination can result in dangerous or even fatal levels of respiratory depression. These substances potentiate the muscle relaxation, sedation and amnesia caused by one another and can lead to unexpected loss of consciousness at high doses. There is also an increased risk of vomiting during unconsciousness and death from the resulting suffocation. If this occurs, users should attempt to fall asleep in the recovery position or have a friend move them into it.
  • Dissociatives - This combination can result in an increased risk of vomiting during unconsciousness and death from the resulting suffocation. If a sudden loss of consciousness occurs, users should attempt to fall asleep in the recovery position or have a friend move them into it.
  • Stimulants - Phenibut is reported to enhance the positive effects of stimulants as well as reduce jitteriness and anxiety.[14] However, this combination can be dangerous due to the risk of excessive intoxication. Stimulants mask the sedative effects of phenibut; once the stimulant wears off, the depressant effects of phenibut will be significantly increased, leading to intensified disinhibition as well as other effects. If combined, one should strictly limit themselves to a certain dose of phenibut prior to stimulant consumption and not redose. This combination can also potentially result in significant dehydration.
  • Australia: Phenibut is a schedule 9 substance in Australia as of February 1st 2018, meaning it is illegal to possess, import, supply or manufacture.[citation needed]
  • Canada: Phenibut is not a controlled substance in Canada, meaning it is legal to possess without any sort of license or prescription. [citation needed]
  • Germany: Phenibut may be controlled under the NpSG (New Psychoactive Substances Act)[15] as of July 18, 2019. [16] If this law applies to Phenibut remains unclear.[17][18]
  • Italy: Phenibut is a Schedule 1 controlled substance.[19]
  • Latvia: Phenibut is an unscheduled prescription drug, marketed as "Noofen".[20][21]
  • Switzerland: Phenibut is not controlled under Buchstabe A, B, C and D. It could be considered legal.[22]
  • United Kingdom: Phenibut is not a controlled substance in the United Kingdom. It may be illegal to produce, supply, or import this drug under the Psychoactive Substance Act 2016, which applies a blanket restriction on all "psychoactive substances" with exemptions for alcohol, nicotine and "medicinal products".[23]
  • United States: Phenibut is not a controlled substance in the United States, meaning it is federally legal to possess without any sort of license or prescription.[24]Phenibut is a Schedule II controlled substance in Alabama as of November 21st, 2021.[25]

See also

References

  1. Risks of Combining Depressants - TripSit 
  2. Wyllie, E., Cascino, G. D., Gidal, B. E., Goodkin, H. P. (17 February 2012). Wyllie’s Treatment of Epilepsy: Principles and Practice. Lippincott Williams & Wilkins. ISBN 9781451153484. 
  3. Benzon, H., Rathmell, J. P., Wu, C. L., Turk, D., Argoff, C. E., Hurley, R. W. (11 September 2013). Practical Management of Pain E-Book. Elsevier Health Sciences. ISBN 9780323170802. 
  4. 4.0 4.1 4.2 4.3 Lapin, I. (7 June 2006). "Phenibut (β-Phenyl-GABA): A Tranquilizer and Nootropic Drug". CNS Drug Reviews. 7 (4): 471–481. doi:10.1111/j.1527-3458.2001.tb00211.x. ISSN 1080-563X. 
  5. Shulgina, G. I. (December 1986). "On neurotransmitter mechanisms of reinforcement and internal inhibition". The Pavlovian Journal of Biological Science. 21 (4): 129–140. doi:10.1007/BF02734511. ISSN 0093-2213. 
  6. 6.0 6.1 Group, D. W. (25 February 2015). Encyclopedia of Mind Enhancing Foods, Drugs and Nutritional Substances, 2d ed. McFarland. ISBN 9780786441426. 
  7. Shulgina, G. I. (October 1986). "On neurotransmitter mechanisms of reinforcement and internal inhibition". The Pavlovian Journal of Biological Science. 21 (4): 129–140. doi:10.1007/BF02734511. ISSN 0093-2213. 
  8. Lapin, I. (2001). "Phenibut (beta-phenyl-GABA): a tranquilizer and nootropic drug". CNS drug reviews. 7 (4): 471–481. doi:10.1111/j.1527-3458.2001.tb00211.x. ISSN 1080-563X. 
  9. Dambrova, M., Zvejniece, L., Liepinsh, E., Cirule, H., Zharkova, O., Veinberg, G., Kalvinsh, I. (March 2008). "Comparative pharmacological activity of optical isomers of phenibut". European Journal of Pharmacology. 583 (1): 128–134. doi:10.1016/j.ejphar.2008.01.015. ISSN 0014-2999. 
  10. GABAb Receptor Pharmacology: A Tribute to Norman Bowery. Academic Press. 21 September 2010. ISBN 9780123786487. 
  11. Zyablitseva, E. A.; Pavlova, I. V. (2010). "Effects of the GABA Receptor Agonist Phenibut on Spike Activity and Interactions between Neocortex and Hippocampus Neurons in Emotionally Negative Situations". Neuroscience and Behavioral Physiology. 40 (9): 1003–1011. doi:10.1007/s11055-010-9360-y. ISSN 0097-0549. 
  12. 12.0 12.1 12.2 Dambrova, M., Zvejniece, L., Liepinsh, E., Cirule, H., Zharkova, O., Veinberg, G., Kalvinsh, I. (31 March 2008). "Comparative pharmacological activity of optical isomers of phenibut". European Journal of Pharmacology. 583 (1): 128–134. doi:10.1016/j.ejphar.2008.01.015. ISSN 0014-2999. 
  13. Koski, A., Ojanpera, I., Vuori, E. (July 2002). "Alcohol and Benzodiazepines in Fatal Poisonings". Alcoholism: Clinical and Experimental Research. 26 (7): 956–959. doi:10.1111/j.1530-0277.2002.tb02627.x. ISSN 0145-6008. 
  14. The Drug Classroom - Phenibut: Combinations 
  15. "Anlage NpSG" (in Deutsch). Bundesministerium der Justiz und für Verbraucherschutz. Retrieved December 10, 2019. 
  16. "Verordnung zur Änderung der Anlage des Neue-psychoaktive-Stoffe-Gesetzes und von Anlagen des Betäubungsmittelgesetzes" (PDF). Bundesgesetzblatt Jahrgang 2019 Teil I (in Deutsch). Bundesanzeiger Verlag. July 17, 2019. Retrieved December 28, 2019. 
  17. "§ 4 NpSG" (in Deutsch). Bundesministerium der Justiz und für Verbraucherschutz. Retrieved December 10, 2019. 
  18. Evaluation der Auswirkungen des Neue-psychoaktive-Stoffe-Gesetzes (NpSG): Abschlussbericht.
  19. Tabella 1(PDF) (in Italian). Ministero della Salute [Ministry of Health]. p.19. Retrieved November 24, 2020.
  20. https://dati.zva.gov.lv/zalu-registrs/?iss=1&q=Phenibutum Database of licensed phenibut medicines and their legal status under the State Agency of Medicines of the Republic of Latvia. Retrieved August 26, 2023.
  21. https://likumi.lv/ta/en/en/id/50539 Active Latvian law regarding scheduled and banned substances. Retrieved August 26, 2023.
  22. "Verordnung des EDI über die Verzeichnisse der Betäubungsmittel, psychotropen Stoffe, Vorläuferstoffe und Hilfschemikalien" (in Deutsch). Bundeskanzlei [Federal Chancellery of Switzerland]. Retrieved January 1, 2020. 
  23. Psychoactive Substances Act 2016 
  24. Erowid Phenibut Vault: Legal Status 
  25. Alabama List of Controlled Substanceshttps://www.alabamapublichealth.gov/blog/assets/controlledsubstanceslist.pdf