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psx:substance/f-phenibut/proposal/dose_tier/cfddab9d-1a0c-4108-b590-28cd36a42763

proposal2026-04-28recordapproved

derived from · upstream

none recorded

feeds · downstream

Closure of psx:substance/f-phenibut/proposal/dose_tier/cfddab9d-1a0c-4108-b590-28cd36a42763: 0 upstream, 1 downstream.

psx:substance/f-phenibut/proposal/dose_tier/cfddab9d-1a0c-4108-b590-28cd36a42763
└─ derived_from  value/dose_tier/common@1

indented by distance from this node, not by parentage

1Provenance card

the boundary, as counts

Sources

2622 with DOI

0 strong · 15 moderate · 11 weak

Compilations

12026-04-28T03:36:15.025Z

pipeline-v5 · prompt hash not recorded — run predates 2026-09

Decisions

31last ruled 2026-06-04

1 awaiting a ruling

Issued documents

42026-10-19T20:31:57.688Z

notice · info card · emergency

Searches

243 with no results

queries and counts on the build

Claims checked

8265 supported

65 supported · 17 not

Correspondence

0received

consent field ships in Phase 4

Edges

257

derivations recorded for this entity

Complete over 26 sources, 1 compilation, and 31 decisions.Not here: the private journal (never); 1 proposal awaiting a ruling (listed as pending only).Working material — drafts, discards, unsupported claims — is listed below and readable on the working page.Cite: psychedex.org/substances/f-phenibut/archive

2Build

one panel per compilation run

generation run 2026-04-28

53 min completedmodel pipeline-v5plan not recordedrun/8d6ed613…

Selection

results seen97
selected by the model30
consumed as sources26

Verification

claims checked82
supported62
partially supported3
not supported3
inconclusive14
  • record
  • seen / partial
  • working

The model's own caveats

  • class_inference
  • dose_equivalence_gap

Reproduce

inputs
26 source keys (listed under Sources)
plan
not recorded — template version, prompt hash and git SHA are written from 2026-09 onward
model
pipeline-v5
streams
none — agent transcripts are persisted from 2026-09 onward
24 searches — query, source, results, what was kept and why
24 searches for this run
#sourcequeryseenkeptrationale
1HandWiki—13—
2PubMed · absenceF-phenibut fluorophenibut pharmacology0——
3WebSearchF-phenibut 4-fluorophenibut legal status scheduling UK EU US Australia101—
4PubMedphenibut alpha-2-delta calcium channel voltage gated gabapentin binding1——
5PubChem · absencefluorophenibut0——
6PMC—12—
7PubMedPMID 32735986 full record1——
8PubChem4-fluorophenibut (CID 103611)11—
9ClinicalTrials.gov · absenceF-phenibut fluorophenibut0——
10WebSearchF-phenibut CGP-11130 SMILES structure history discovery102—
11OpenAlexF-phenibut fluorophenibut GABA-B receptor21—
12PubMedphenibut GABA-B receptor agonist pharmacology156—
13PubMedbaclofen GABA-B agonist abuse dependence withdrawal treatment51—
14PsychonautWiki—11—
15PubMedZvejniece R-phenibut pharmacology neuroprotective22—
16WebSearchF-phenibut CGP-11130 GABA-B IC50 original paper reference100—
17WebSearchphenibut Australia Schedule 4 TGA 2021 scheduling101—
18WebSearchF-phenibut Canada legal controlled substance NPS survey101—
19MultipleF-phenibut dose/duration cross-reference PsychonautWiki vs brief seed data21—
20MultipleCompile all F-phenibut chemical identity data11—
21PubMedZvejniece phenibut GABA-B pharmacology Latvia22—
22PubMedPMID 34550038 phenibut dietary supplement FDA warning11—
23PMC—12—
24WebSearchWHO ECDD phenibut 44th pre-review scheduling recommendation101—
82 claims by section — every cited sentence, checked against its source
safety28 · 19 ok
  • Claim in safety — inconclusiveinconclusiveworking →

  • Management is supportive: airway protection, ventilatory support, and hemodynamic monitoring.supported

    30-year-old with phenibut intoxication requiring sedation and mechanical ventilation. cureus.23913

  • The primary acute hazard derives from F-phenibut's approximately 58-fold higher GABA-B potency relative to phenibutsupported

    F-phenibut ~58x more potent than phenibut, ~4x less potent than baclofen. j.ejphar.2020.173437

  • Claim in safety — inconclusiveinconclusiveworking →

  • More than 80 cases of coma and death have been associated with phenibut consumption and withdrawal in the United States, though most involve polydrug contextssupported

    More than 80 cases of coma and death associated. FDA warned phenibut not permitted in supplements. 15563650.2021.1973020

  • A case of suspected phenibut intoxication presenting with partial brainstem areflexia has been documented, and dissociative features during intoxication have been reported.supported

    Unconscious patient with brainstem areflexia after phenibut ingestion; ICU admission. v07250573

  • A case of suspected phenibut intoxication presenting with partial brainstem areflexia has been documented, and dissociative features during intoxication have been reported.supported

    Case report of dissociative intoxication and prolonged withdrawal associated with phenibut. jcp.0000000000000731

  • Identification requires specialized LC-MS/MS methods not routinely available in emergency departmentssupported

    No readily available confirmatory lab tests. cureus.23913

  • Identification requires specialized LC-MS/MS methods not routinely available in emergency departmentssupported

    Routine drug screening limitations highlighted. bkac023

  • Acute psychological adverse effects at supratherapeutic doses include paradoxical anxiety (anxiogenic rebound), cognitive impairment, amnesia, and dissociative symptomssupported

    Case report of dissociative intoxication and prolonged withdrawal associated with phenibut. jcp.0000000000000731

  • Claim in safety — inconclusiveinconclusiveworking →

  • Claim in safety — inconclusiveinconclusiveworking →

  • Claim in safety — inconclusiveinconclusiveworking →

  • Withdrawal symptoms can begin within 3–4 hours of the last dose and include severe psychomotor agitation, autonomic instability, neurological signs mimicking serotonin syndrome or neuroleptic malignant syndrome, psychosis, and seizuressupported

    Tolerance and significant withdrawal within 3-4 h of last use. bcr-2012-008381

  • Claim in safety — inconclusiveinconclusiveworking →

  • Withdrawal symptoms can begin within 3–4 hours of the last dose and include severe psychomotor agitation, autonomic instability, neurological signs mimicking serotonin syndrome or neuroleptic malignant syndrome, psychosis, and seizuressupported

    Severe psychomotor agitation prominent. Neurologic and autonomic signs may mimic serotonin or neuroleptic malignant syndrome. bjbms.2018.4008

  • The higher potency of F-phenibut relative to phenibut suggests potentially more rapid dependence development at lower absolute doses, though this has not been formally studied.supported

    F-phenibut ~58x more potent than phenibut, ~4x less potent than baclofen. j.ejphar.2020.173437

  • Baclofen substitution and taper is the primary documented withdrawal management strategy, at approximately 10 mg baclofen per 1 g phenibut equivalencesupported

    Substitution with baclofen (~10 mg baclofen per gram phenibut), then baclofen taper over 9 weeks. bcr-2012-008381

  • Benzodiazepines and phenobarbital are alternatives; phenobarbital may be preferred when seizure risk is elevatedsupported

    Among 29 cases of withdrawal, patients treated with baclofen, benzodiazepines, and phenobarbital. Baclofen tapers successful; phenobarbital preferred if seizure risk. jcph.2414

  • Claim in safety — inconclusiveinconclusiveworking →

  • Claim in safety — not_supportednot supportedworking →

  • Polydependence on phenibut and benzodiazepines has been documented, requiring coordinated withdrawal management.supported

    Case of comorbid phenibut and benzodiazepine dependence managed by baclofen tapering. jcp.0000000000001104

  • Alcohol presents a complex interaction: GABA-B agonism reduces the stimulating and rewarding properties of alcohol, but concurrent use produces additive CNS depression with increased risk of respiratory compromise and aspiration.partially supported

    GABA-B receptor activation (primarily via baclofen) reduces stimulating/rewarding effects of alcohol, signs of alcohol withdrawal, alcohol drinking, motivational properties of alcohol, and alcohol-seeking. 7854_2020_178

  • Other GABA-B agonists (baclofen, ghb, gbl) produce additive GABA-B receptor activation with risk of severe CNS depression.supported

    GHB and analogs as CNS depressants. GABA-B agonism mechanism of toxicity. 15563650.2012.702218

  • Phenibut withdrawal has been noted to mimic serotonin syndrome clinically, but this represents a mimicry syndrome rather than a true serotonergic pharmacological interactionsupported

    Neurologic and autonomic signs may mimic serotonin or neuroleptic malignant syndrome. bjbms.2018.4008

  • Given the minimal hepatic metabolism of the phenibut class, CYP-mediated pharmacokinetic drug interactions are not expected but have not been studied.supported

    Elimination t1/2 5-6h, bioavailability ~65%, excreted unchanged. arztebl.m2024.0003

  • Claim in safety — inconclusiveinconclusiveworking →

  • Renal impairment — Phenibut is excreted largely unchanged in urinesupported

    Elimination t1/2 5-6h, bioavailability ~65%, excreted unchanged. arztebl.m2024.0003

pharmacology12 · 12 ok
  • F-phenibut is a potent agonist at the GABA-B receptor, a class C G-protein coupled receptor forming obligate GB1/GB2 heterodimerssupported

    Obligate heterodimers (R1+R2 subunits). pjab.94.026

  • F-phenibut is a potent agonist at the GABA-B receptor, a class C G-protein coupled receptor forming obligate GB1/GB2 heterodimerssupported

    GABA-B class C GPCR heterodimer. VFT and 7TM domains. molecules25133093

  • Downstream signaling proceeds through Gαi/o proteins, producing inactivation of voltage-gated Ca²⁺ channels, activation of inwardly rectifying K⁺ channels (GIRK/Kir3), and inhibition of adenylate cyclase.supported

    GABA-B receptors are GPCRs mediating slow inhibitory action via Gai/o. Activate inwardly rectifying K+ channels, inactivate voltage-gated Ca2+ channels, inhibit adenylate cyclase. pjab.94.026

  • In mouse cerebellar Purkinje cells, F-phenibut activated K⁺ currents with an EC₅₀ of 23.3 µM, compared with 1362 µM for phenibut and 6.0 µM for baclofen — establishing F-phenibut as approximately 58 times more potent than phenibut and 4 times less potent than baclofen at GABA-Bsupported

    EC50 for GABA-B-mediated outward K+ current in Purkinje cells: phenibut 1362 µM, F-phenibut 23.3 µM, baclofen 6.0 µM. F-phenibut ~58x more potent than phenibut, ~4x less potent than baclofen. j.ejphar.2020.173437

  • F-phenibut suppressed action potential generation in Purkinje cells, consistent with its CNS depressant profile.supported

    F-phenibut suppresses action potential generation in Purkinje cells. j.ejphar.2020.173437

  • R-phenibut binds the α₂-δ subunit with Ki = 23 µM, approximately 4 times higher affinity than its GABA-B binding (Ki = 92 µM), and the anti-nociceptive effects of R-phenibut are mediated via α₂-δ rather than GABA-B, as demonstrated by insensitivity to the GABA-B antagonist CGP35348supported

    Binding affinities for α2-δ subunit: R-phenibut Ki=23 µM. R-phenibut α2-δ affinity is 4x higher than GABA-B affinity. Anti-nociceptive effects mediated via α2-δ, not GABA-B. j.pbb.2015.07.014

  • Phenibut also stimulates dopamine receptors and antagonizes β-phenethylamine (PEA), a putative endogenous anxiogenicsupported

    Also stimulates dopamine receptors and antagonizes β-phenethylamine (PEA). pmid:11830761

  • Phenibut exhibits minor GABA-A activity at very high concentrations, but this is not expected to be clinically significant for F-phenibut at doses producing GABA-B-mediated effects.supported

    Phenibut acts as GABA-B agonist and has high affinity at alpha-2-delta subunit calcium channels (gabapentinoid activity), plus minor GABA-A activity. jcp.0000000000001759

  • Phenibut exhibits oral bioavailability of approximately 65%, with maximal brain concentrations reached within approximately 15 minutes of administration in mice (R-phenibut data)partially supported

    Elimination t1/2 5-6h, bioavailability ~65%, excreted unchanged. arztebl.m2024.0003

  • Phenibut exhibits oral bioavailability of approximately 65%, with maximal brain concentrations reached within approximately 15 minutes of administration in mice (R-phenibut data)supported

    R-phenibut reaches brain tissue 15 min after i.p./p.o. CNS penetration data. 9364598

  • The elimination half-life is approximately 5–6 hourssupported

    Elimination t1/2 5-6h, bioavailability ~65%, excreted unchanged. arztebl.m2024.0003

  • Hepatic metabolism is virtually absent — phenibut is excreted largely unchanged in urine — and CYP enzyme involvement has not been established.supported

    Elimination t1/2 5-6h, bioavailability ~65%, excreted unchanged. arztebl.m2024.0003

neuroscience10 · 7 ok
  • Baclofen reduces the rewarding properties of alcohol and stimulants, yet phenibut-class compounds themselves carry significant dependence liability — suggesting that negative reinforcement (escape from baseline anxiety, relief from inter-dose withdrawal) drives compulsive use more powerfully than positive hedonic reward.supported

    GABA-B receptor activation (primarily via baclofen) reduces stimulating/rewarding effects of alcohol, signs of alcohol withdrawal, alcohol drinking, motivational properties of alcohol, and alcohol-seeking. 7854_2020_178

  • Claim in neuroscience — inconclusiveinconclusiveworking →

  • Activation of presynaptic GABA-B heteroreceptors inhibits neurotransmitter release (glutamate, monoamines, GABA itself) via inactivation of voltage-gated Ca²⁺ channels, while postsynaptic GABA-B receptors hyperpolarize neurons through activation of K⁺ conductances.supported

    Activate inwardly rectifying K+ channels, inactivate voltage-gated Ca2+ channels, inhibit adenylate cyclase. pjab.94.026

  • In cerebellar Purkinje cells specifically, F-phenibut activates an outward-rectifying K⁺ current rather than the conventional GIRK-mediated inward rectificationsupported

    Current is outward-rectifying, insensitive to Ba2+, Cs+, TEA-Cl. j.ejphar.2020.173437

  • The putative α₂-δ VDCC subunit binding (inferred from phenibut data) would add a gabapentinoid component — reduction of excitatory neurotransmitter release through presynaptic Ca²⁺ channel modulation — that could contribute to anxiolysis, anti-nociception, and the subjective warmth reported by users.supported

    R-phenibut binds to the α2-δ subunit of voltage-dependent calcium channels and exerts gabapentin-like anti-nociceptive effects. Anti-nociceptive effects mediated via α2-δ, not GABA-B. j.pbb.2015.07.014

  • If dopaminergic activity analogous to phenibut's is present, mesolimbic dopamine pathway facilitation could explain the mood elevation and motivation enhancement reported at lower doses, as well as the compulsive redosing potential.supported

    Also stimulates dopamine receptors and antagonizes β-phenethylamine (PEA). pmid:11830761

  • Claim in neuroscience — inconclusiveinconclusiveworking →

  • Claim in neuroscience — inconclusiveinconclusiveworking →

  • Is the outward-rectifying K⁺ current observed in Purkinje cells present in other brain regions, or is it cerebellar-specific? If widespread, it represents a novel GABA-B effector pathway with implications for the entire compound class.supported

    Current is outward-rectifying, insensitive to Ba2+, Cs+, TEA-Cl. F-phenibut suppresses action potential generation in Purkinje cells. j.ejphar.2020.173437

  • Does F-phenibut produce neuroplasticity changes (BDNF upregulation, synaptogenesis) at sub-sedating doses, as suggested by phenibut's nootropic effects in animal models?supported

    Aryl GABA analogs (phenibut, baclofen, tolibut) show nootropic activity. Structure-activity comparison of the chemical series. s10517-016-3198-4

summary9 · 7 ok
  • With an EC₅₀ of 23.3 µM at GABA-B — approximately 58 times more potent than phenibut and 4 times less potent than baclofen — F-phenibut occupies an intermediate position in the halogenated β-phenyl-GABA seriessupported

    EC50 for GABA-B-mediated outward K+ current in Purkinje cells: phenibut 1362 µM, F-phenibut 23.3 µM, baclofen 6.0 µM. F-phenibut ~58x more potent than phenibut, ~4x less potent than baclofen. j.ejphar.2020.173437

  • Claim in summary — inconclusiveinconclusiveworking →

  • Population-level use has been confirmed through detection in Australian wastewater surveys.supported

    4F-phenibut detected across 57 catchments alongside phenibut. Detection frequency ranged 3–100% of sites analyzed. j.scitotenv.2024.170473

  • F-phenibut activates GABA-B receptors (EC₅₀ = 23.3 µM), triggering downstream Gαi/o-mediated inhibition of voltage-gated Ca²⁺ channels and activation of K⁺ conductancespartially supported

    EC50 for GABA-B-mediated outward K+ current in Purkinje cells: F-phenibut 23.3 µM. Current is outward-rectifying, insensitive to Ba2+, Cs+, TEA-Cl. j.ejphar.2020.173437

  • F-phenibut activates GABA-B receptors (EC₅₀ = 23.3 µM), triggering downstream Gαi/o-mediated inhibition of voltage-gated Ca²⁺ channels and activation of K⁺ conductancessupported

    GABA-B receptors are GPCRs mediating slow inhibitory action via Gai/o. Activate inwardly rectifying K+ channels, inactivate voltage-gated Ca2+ channels. pjab.94.026

  • By structural analogy with phenibut, additional binding at the α₂-δ subunit of voltage-dependent calcium channels is expected but has not been directly measured.supported

    Binding affinities for α2-δ subunit: R-phenibut Ki=23 µM, S-phenibut Ki=39 µM, baclofen Ki=156 µM, gabapentin Ki=0.05 µM. j.pbb.2015.07.014

  • The primary acute hazard is its 58-fold potency increase over phenibut, creating substantial overdose risk when users miscalculate dose conversionssupported

    F-phenibut ~58x more potent than phenibut, ~4x less potent than baclofen. j.ejphar.2020.173437

  • Claim in summary — inconclusiveinconclusiveworking →

  • Tolerance develops within days of continuous use, and physical dependence with a severe withdrawal syndrome — including psychomotor agitation, autonomic instability, psychosis, and seizures — is documented for the phenibut classsupported

    Severe psychomotor agitation prominent. Neurologic and autonomic signs may mimic serotonin or neuroleptic malignant syndrome. bjbms.2018.4008

clinical-evidence7 · 7 ok
  • Published phenibut clinical data include a systematic literature review of toxicity and withdrawal encompassing multiple case reports, a comprehensive review of acute withdrawal, and individual case reports of dependence, polydependence with benzodiazepines, dissociative intoxication, and suspected brainstem involvement during severe intoxicationsupported

    Systematic review of published articles evaluating phenibut toxicity and withdrawal cases to understand clinical presentations and treatments. adm.0000000000001141

  • Published phenibut clinical data include a systematic literature review of toxicity and withdrawal encompassing multiple case reports, a comprehensive review of acute withdrawal, and individual case reports of dependence, polydependence with benzodiazepines, dissociative intoxication, and suspected brainstem involvement during severe intoxicationsupported

    Review of 22 published phenibut withdrawal cases. Severe psychomotor agitation prominent. bjbms.2018.4008

  • Published phenibut clinical data include a systematic literature review of toxicity and withdrawal encompassing multiple case reports, a comprehensive review of acute withdrawal, and individual case reports of dependence, polydependence with benzodiazepines, dissociative intoxication, and suspected brainstem involvement during severe intoxicationsupported

    Case of phenibut dependence for self-medication of anxiety, insomnia, and alcohol cravings. bcr-2012-008381

  • Published phenibut clinical data include a systematic literature review of toxicity and withdrawal encompassing multiple case reports, a comprehensive review of acute withdrawal, and individual case reports of dependence, polydependence with benzodiazepines, dissociative intoxication, and suspected brainstem involvement during severe intoxicationsupported

    Case of comorbid phenibut and benzodiazepine dependence managed by baclofen tapering. jcp.0000000000001104

  • Published phenibut clinical data include a systematic literature review of toxicity and withdrawal encompassing multiple case reports, a comprehensive review of acute withdrawal, and individual case reports of dependence, polydependence with benzodiazepines, dissociative intoxication, and suspected brainstem involvement during severe intoxicationsupported

    Case report of dissociative intoxication and prolonged withdrawal associated with phenibut. jcp.0000000000000731

  • Published phenibut clinical data include a systematic literature review of toxicity and withdrawal encompassing multiple case reports, a comprehensive review of acute withdrawal, and individual case reports of dependence, polydependence with benzodiazepines, dissociative intoxication, and suspected brainstem involvement during severe intoxicationsupported

    Unconscious patient with brainstem areflexia after phenibut ingestion; ICU admission. v07250573

  • The sole primary pharmacology study — Irie et al. (2020) — was an in vitro electrophysiology investigation in mouse cerebellar Purkinje cells, not a clinical or whole-animal efficacy study.supported

    EC50 for GABA-B-mediated outward K+ current in Purkinje cells: phenibut 1362 µM, F-phenibut 23.3 µM, baclofen 6.0 µM. j.ejphar.2020.173437

chemistry5 · 4 ok
  • The defining structural feature is a fluorine atom at the para position of the phenyl ring, placing F-phenibut in a halogen series between the unsubstituted phenibut and the para-chloro-substituted baclofen (β-(4-chlorophenyl)-GABA)supported

    Discusses structure-activity relationship of phenibut and derivatives including baclofen. pmid:11830761

  • The defining structural feature is a fluorine atom at the para position of the phenyl ring, placing F-phenibut in a halogen series between the unsubstituted phenibut and the para-chloro-substituted baclofen (β-(4-chlorophenyl)-GABA)supported

    Aryl GABA analogs (phenibut, baclofen, tolibut) show nootropic activity. Structure-activity comparison of the chemical series. s10517-016-3198-4

  • The electron-withdrawing fluorine enhances GABA-B receptor binding, consistent with the approximately 58-fold potency increase over unsubstituted phenibut.supported

    F-phenibut ~58x more potent than phenibut, ~4x less potent than baclofen. j.ejphar.2020.173437

  • By analogy with phenibut, where the R-enantiomer carries essentially all GABA-B agonist activity and S-phenibut is inactive at GABA-B, and with baclofen, where R(+)-baclofen is the pharmacologically dominant enantiomer, the R-enantiomer of F-phenibut is expected to carry the majority of GABA-B activitysupported

    GABA-B binding affinities: racemic phenibut Ki=177 uM, R-phenibut Ki=92 uM, baclofen Ki=6.0 uM. S-phenibut inactive. R-phenibut 2x more potent than racemic form. j.ejphar.2008.01.015

  • Claim in chemistry — not_supportednot supportedworking →

comparative-pharmacology4 · 4 ok
  • All EC₅₀ values derive from the same assay system (mouse cerebellar Purkinje cell K⁺ current).supported

    EC50 for GABA-B-mediated outward K+ current in Purkinje cells: phenibut 1362 µM, F-phenibut 23.3 µM, baclofen 6.0 µM. j.ejphar.2020.173437

  • R-phenibut binds the α₂-δ VDCC subunit with Ki = 23 µM — far weaker than gabapentin (Ki = 0.05 µM) but sufficient to produce gabapentin-like anti-nociceptive effects in animal modelssupported

    Binding affinities for α2-δ subunit: R-phenibut Ki=23 µM, gabapentin Ki=0.05 µM. Anti-nociceptive effects mediated via α2-δ, not GABA-B. j.pbb.2015.07.014

  • Unlike baclofen, which is used clinically as a skeletal muscle relaxant and is under investigation for alcohol use disorder, F-phenibut has no clinical applications and no regulatory pathwaysupported

    Strong preclinical evidence for GABA-B as therapeutic target for AUD. 7854_2020_178

  • Unlike phenibut, which is available as a prescription medication in Russia and as an unregulated supplement in some Western markets, F-phenibut exists exclusively in the research chemical marketsupported

    Historical review: phenibut discovered and introduced into clinical practice in Russia in the 1960s. pmid:11830761

history3 · 2 ok
  • The parent compound, phenibut, was discovered and introduced into clinical practice in the Soviet Union in the 1960s, where it gained widespread use as an anxiolytic and nootropic agentsupported

    Historical review: phenibut discovered and introduced into clinical practice in Russia in the 1960s. pmid:11830761

  • F-phenibut became commercially available from online nootropic and research chemical vendors in the 2010s, marketed under names including "F-phenibut," "fluorophenibut," "fluorobut," and "4F-phenibut." Its presence in the general population was confirmed by a systematic wastewater-based epidemiology survey in Australia spanning February 2022 to February 2023, which detected 4-fluorophenibut alongside other novel psychoactive substances.supported

    Wastewater-based epidemiology of NPS in Australia (Feb 2022–Feb 2023). 4F-phenibut detected across 57 catchments alongside phenibut. j.scitotenv.2024.170473

  • Claim in history — inconclusiveinconclusiveworking →

receptor-pharmacology3 · 2 ok
  • Irie et al. reported that the K⁺ current activated by F-phenibut, phenibut, and baclofen in cerebellar Purkinje cells is outward-rectifying — pharmacologically distinct from the inwardly rectifying K⁺ current (GIRK/Kir3) conventionally associated with GABA-B receptor activationsupported

    Current is outward-rectifying, insensitive to Ba2+, Cs+, TEA-Cl. j.ejphar.2020.173437

  • By analogy with phenibut, where R-phenibut is approximately 2 times more potent than the racemate and S-phenibut is inactive at GABA-B, and with baclofen, where R(+)-baclofen is the active enantiomer, the pharmacological activity of racemic F-phenibut is expected to reside predominantly in the R-enantiomersupported

    GABA-B binding affinities: racemic phenibut Ki=177 uM, R-phenibut Ki=92 uM. S-phenibut inactive. R-phenibut 2x more potent than racemic form. j.ejphar.2008.01.015

  • Claim in receptor-pharmacology — not_supportednot supportedworking →

pharmacokinetic-detail1 · 1 ok
  • Given the minimal hepatic metabolism of the phenibut class, CYP-mediated pharmacokinetic interactions with F-phenibut are not expectedsupported

    Elimination t1/2 5-6h, bioavailability ~65%, excreted unchanged. arztebl.m2024.0003

3Sources

26 consumed · sorted by year · feeds = sections resting on it

Sources
yearsourcetierstatusfeeds
2026Suspected phenibut poisoning with brainstem involvementJensen JMS et al. · Ugeskrift for Laegerdoi:10.61409/v07250573weakconsumedcited only
2024F-Phenibut - PsychonautWikiPsychonautWiki contributorsurl:8d14974153caf611weakconsumedcited only
2024Monitoring the use of novel psychoactive substances in Australia by wastewater-based epidemiologyJaunay EL, Bade R, Paxton KR, Nadarajan D, Barry DC, Zhai Y, Tscharke BJ, O'Brien JW, Mueller J, White JM, Simpson BS, Gerber C · The Science of the Total Environmentdoi:10.1016/j.scitotenv.2024.170473moderateconsumed2 sections
2024Phenibut: Review and Pharmacologic Approaches to Treating WithdrawalPenzak SR, Bulloch M · Journal of Clinical Pharmacologydoi:10.1002/jcph.2414moderateconsumed1 section
2024Phenibutan - an Illegal Food Supplement With Psychotropic Effects and Health RisksBonnet U, Scherbaum N, Schaper A, Soyka M · Deutsches Arzteblatt Internationaldoi:10.3238/arztebl.m2024.0003moderateconsumed3 sections
2024Toxidrome of an Easily Obtainable Nootropic: A Case Report of Phenibut Intoxication and Withdrawal DeliriumMartin R, Buffenstein I, Cho D, Kiyokawa M · Journal of Clinical Psychopharmacologydoi:10.1097/jcp.0000000000001759weakconsumedcited only
20234-Fluorophenibut (HandWiki Chemistry article)HandWiki contributorsurl:ddc52dd7168b6c81weakconsumedcited only
2023Clinical Presentations and Treatment of Phenibut Toxicity and Withdrawal: A Systematic Literature ReviewWeleff J, Kovacevich A, Burson J, Nero N, Anand A · Journal of Addiction Medicinedoi:10.1097/adm.0000000000001141moderateconsumedcited only
2022An Unusual Presentation of an Uncommon Drug: A Case Report on Phenibut OverdoseNedzlek CD, Michaelis A · Cureusdoi:10.7759/cureus.23913weakconsumed1 section
2022Chronic Phenibut Use: Symptoms, Severe Withdrawal, and RecoveryVanDreese B, Holland A, Murray A · WMJpmid:35442585weakconsumed1 section
2022GABA-B Receptors and Alcohol Use Disorders: Preclinical StudiesHoltyn AF, Weerts EM · Current Topics in Behavioral Neurosciencesdoi:10.1007/7854_2020_178moderateconsumed5 sections
2022Quantity of phenibut in dietary supplements before and after FDA warningsCohen PA, Ellison RR, Travis JC, Gaufberg SV, Gerona R · Clinical Toxicologydoi:10.1080/15563650.2021.1973020moderateconsumed1 section
2022Reports of Adverse Events Associated with Use of Novel Psychoactive Substances, 2017–2020: A ReviewMohr ALA, Logan BK, Fogarty MF, Krotulski AJ, Papsun DM, et al. · Journal of Analytical Toxicologydoi:10.1093/jat/bkac023moderateconsumed1 section
2021Unedited Advance Copy Pre-Review Report: PhenibutWHO Expert Committee on Drug Dependenceurl:8a46b9a2cad022e2weakconsumedcited only
2020F-phenibut (beta-(4-Fluorophenyl)-GABA), a potent GABA-B receptor agonist, activates an outward-rectifying K+ current and suppresses action potentials in mouse cerebellar Purkinje cellsIrie T, Yamazaki D, Kikura-Hanajiri R · European Journal of Pharmacologydoi:10.1016/j.ejphar.2020.173437moderateconsumed9 sections
2020Mitochondrial-Protective Effects of R-Phenibut after Experimental Traumatic Brain InjuryKupats E, Stelfa G, Zvejniece B, et al. · Oxidative Medicine and Cellular Longevitydoi:10.1155/2020/9364598moderateconsumed1 section
2020The GABA-B Receptor - Structure, Ligand Binding and Drug DevelopmentEvenseth LSM, Gabrielsen M, Sylte I · Moleculesdoi:10.3390/molecules25133093moderateconsumed2 sections
2019Acute phenibut withdrawal: A comprehensive literature review and illustrative case reportHardman MI, Sprung J, Weingarten TN · Bosnian Journal of Basic Medical Sciencesdoi:10.17305/bjbms.2018.4008weakconsumed3 sections
2019Detoxification of a Patient With Comorbid Dependence on Phenibut and Benzodiazepines by Tapering With BaclofenCoenen NCB, Dijkstra BAG, Batalla A, Schellekens AFA · Journal of Clinical Psychopharmacologydoi:10.1097/jcp.0000000000001104weakconsumedcited only
2018Diversity of structure and function of GABA-B receptors: a complexity of GABA-B-mediated signalingTerunuma M · Proceedings of the Japan Academy, Series Bdoi:10.2183/pjab.94.026moderateconsumed3 sections
2017Dissociative Intoxication and Prolonged Withdrawal Associated With Phenibut: A Case ReportJoshi YB, Friend SF, Jimenez B, Steiger LR · Journal of Clinical Psychopharmacologydoi:10.1097/jcp.0000000000000731weakconsumedcited only
2016Comparison of Nootropic and Neuroprotective Features of Aryl-Substituted Analogs of Gamma-Aminobutyric AcidTyurenkov IN, Borodkina LE, Bagmetova VV, Berestovitskaya VM, Vasil'eva OS · Bulletin of Experimental Biology and Medicinedoi:10.1007/s10517-016-3198-4moderateconsumed2 sections
2015R-phenibut binds to the alpha2-delta subunit of voltage-dependent calcium channels and exerts gabapentin-like anti-nociceptive effectsZvejniece L, Vavers E, Svalbe B, Veinberg G, Rizhanova K, Liepins V, Kalvinsh I, Dambrova M · Pharmacology, Biochemistry, and Behaviordoi:10.1016/j.pbb.2015.07.014moderateconsumed4 sections
2013Phenibut dependenceSamokhvalov AV, Paton-Gay CL, Balchand K, Rehm J · BMJ Case Reportsdoi:10.1136/bcr-2012-008381weakconsumed2 sections
2012The clinical toxicology of gamma-hydroxybutyrate, gamma-butyrolactone and 1,4-butanediolSchep LJ, Knudsen K, Slaughter RJ, Vale JA, Megarbane B · Clinical Toxicologydoi:10.3109/15563650.2012.702218moderateconsumed1 section
2008Comparative pharmacological activity of optical isomers of phenibutDambrova M, Zvejniece L, Liepinsh E, Cirule H, Zharkova O, Veinberg G, Kalvinsh I · European Journal of Pharmacologydoi:10.1016/j.ejphar.2008.01.015moderateconsumed2 sections
—Searched ClinicalTrials.gov for "F-phenibut fluorophenibut" — no resultsabsenceno results—
—Searched PubChem for "fluorophenibut" — no resultsabsenceno results—
—Searched PubMed for "F-phenibut fluorophenibut pharmacology" — no resultsabsenceno results—

4Docket

one filing per activity — decisions, correspondence, reports

awaiting ruling — 1

  • dependence · taper2026-07-03
  1. 0012026-04-28revisionRevision 1

    Initial LLM generation (v5 pipeline, wiki)

    psx:substance/f-phenibut/version/1
  2. 0022026-06-04proposal28 value proposals approved together

    one review action inferred from a shared reviewer and instant — the graph records one activity per proposal

    28 items in this filing

    • dose_tier · light
    • dose_tier · common
    • dose_tier · strong
    • dose_tier · heavy
    • timeline · oral · onset
    • timeline · oral · come_up
    • timeline · oral · peak
    • timeline · oral · plateau
    • timeline · oral · resolution
    • timeline · oral · afterglow
    • toxicity
    • dependence · full
    • withdrawal
    • tolerance
    • dosage · oral
    • duration · oral · onset
    • duration · oral · come_up
    • duration · oral · peak
    • duration · oral · offset
    • duration · oral · total
    • duration · oral · aftereffects
    • contraindication · respiratory
    • contraindication · other
    • contraindication · neurological
    • contraindication · pregnancy_breastfeeding
    • contraindication · renal
    • contraindication · psychiatric
    psx:substance/f-phenibut/proposal/dose_tier/d0436623-b105-45da-afa5-574fb265eb18
  3. 0032026-06-04publicationPublication — backfill

5Issued documents

what the notice, info card and emergency page said, by hash

Issued documents
documentcontent hashissuedfrom versionsuperseded
info_cardd4aa7ab52a471a7d2722856c…2026-10-19 20:31Revision 1current
emergencydcd2ca271fbe095dc7fb6211…2026-09-04 04:30Revision 1current
info_card17037e5d6dbcd0d335ba4571…2026-09-04 04:30Revision 1superseded2026-10-19
noticee6a54e34a35ead3610854ede…2026-09-04 04:30Revision 1current