Article · Wikipedia archive · Last revised Jun 13, 2026

4-Fluorophenibut

4-Fluorophenibut (developmental code name CGP-11130; also known as β-(4-fluorophenyl)-γ-aminobutyric acid or β-(4-fluorophenyl)-GABA) is a GABAB receptor agonist which was never marketed. It is selective for the GABAB receptor over the GABAA receptor (IC50 = 1.70 μM and > 100 μM, respectively). The drug is a GABA analogue and is closely related to baclofen (β-(4-chlorophenyl)-GABA), tolibut (β-(4-methylphenyl)-GABA), and phenibut (β-phenyl-GABA). It is less potent as a GABAB receptor agonist than baclofen but more potent than phenibut.

Last revised
Jun 13, 2026
Read time
≈ 1 min
Length
186 w
Citations
6
Source
Wikipedia ↗
4-Fluorophenibut
Clinical data
Other namesCGP-11130; β-(4-Fluorophenyl)-γ-aminobutyric acid; β-(4-Fluorophenyl)-GABA; Baflofen; Fluorophenibut; F-Phenibut; Fluoribut
Routes of
administration		By mouth
Identifiers
  • 4-Amino-3-(4-fluorophenyl)butanoic acid
CAS Number
PubChem CID
ChemSpider
UNII
CompTox Dashboard (EPA)
Chemical and physical data
FormulaC10H12FNO2
Molar mass197.209 g·mol−1
3D model (JSmol)
  • C1=CC(=CC=C1C(CC(=O)O)CN)F
  • InChI=1S/C10H12FNO2/c11-9-3-1-7(2-4-9)8(6-12)5-10(13)14/h1-4,8H,5-6,12H2,(H,13,14)
  • Key:QWHXHLDNSXLAPX-UHFFFAOYSA-N

4-Fluorophenibut (developmental code name CGP-11130; also known as β-(4-fluorophenyl)-γ-aminobutyric acid or β-(4-fluorophenyl)-GABA) is a GABAB receptor agonist which was never marketed.1 It is selective for the GABAB receptor over the GABAA receptor (IC50 = 1.70 μM and > 100 μM, respectively).1 The drug is a GABA analogue and is closely related to baclofen (β-(4-chlorophenyl)-GABA), tolibut (β-(4-methylphenyl)-GABA), and phenibut (β-phenyl-GABA).1 It is less potent as a GABAB receptor agonist than baclofen but more potent than phenibut.1

The substance is sometimes referred to as 4F-phenibut, F-phenibut, or baflofen, and colloquially as fluorobut.

F-Phenibut is a prohibited substance in Lithuania2 and Hungary.3

References

References

  1. Bowery NG, Hill DR, Hudson AL (1983). "Characteristics of GABAB receptor binding sites on rat whole brain synaptic membranes". Br. J. Pharmacol. 78 (1): 191–206. doi:10.1111/j.1476-5381.1983.tb09380.x. PMC 2044790. PMID 6297646.
  2. "RINKOS RIBOJIMO PRIEMONĖS FENIBUTUI!". ntakd.lrv.lt (in Lithuanian). Archived from the original on 2021-10-06. Retrieved 2020-01-27.
  3. MAGYARORSZÁG HIVATALOS LAPJA. Retrieved 2021-04-28.