Alternative names
GBL
IUPAC Name
oxolan-2-one
Current Scheduling Status
None
Year(s) and type of review / ECDD meetings
Drug Class
Recommendation (from TRS)
Substance identification
Gamma-butyrolactone (GBL) is chemically oxolan-2-one. GBL can be synthesized from ɤ-hydroxybutyric acid (GHB) or tetrahydrofuran.
Previous review
During the pre-review of GHB at the thirty-fourth meeting of the ECDD, the Committee "noted information relating to the abuse of GBL itself (convertible to GHB in the body) and suggested this substance for pre-review". Based on the evidence presented in the pre-review of GBL during the thirty-fifth meeting of the ECDD, given its close association with GHB, and the recommendation made by the Committee at its thirty-fifth meeting to reschedule GHB from Schedule IV to Schedule II of the 1971 Convention, the Committee recommended that a critical review of GBL be undertaken.
Similarity to known substances and effects on the central nervous system
GBL is readily converted, both chemically and in the body, to the Schedule II drug GHB and most of GBL’s pharmacological and toxicological effects are mediated through GHB as a metabolite. Nevertheless, pharmacological factors show that GBL tends to be more potent, faster acting and to have a longer duration of activity than GHB. It is a central nervous system depressant with effects that are exacerbated by other central nervous system depressants (including ethanol). There is a steep dose–effect curve between doses producing desired and excessive effects, and there have been numerous published reports of adverse reactions to GBL including fatalities. Signs and symptoms include euphoria, relaxation, reduced inhibition and sedation, progressing to vomiting, urinary and faecal incontinence, agitation, convulsions, bradycardia, respiratory depression, coma and death.
Dependence potential
Reports of animal studies noted a spontaneous and precipitated withdrawal syndrome after chronic administration of GBL. There have been various reports that, in human users, GBL can produce a withdrawal syndrome when the substance is abruptly discontinued following regular chronic use. Withdrawal from GBL appears similar to withdrawal from other sedative–hypnotic drugs such as ethanol and benzodiazepines.
Actual abuse and/or evidence of likelihood of abuse
GBL abuse and/or seized material have been reported in 18 countries. GBL is sold as a liquid, often presented for illicit sale as GHB but also as a so-called cleaning product via the Internet. It is extremely difficult to accurately assess the magnitude of abuse relating specifically to GBL considering the near absence of data explicitly pertaining to GBL rather than GHB or 1,4-butanediol.
Therapeutic usefulness
While GBL was sold in health food shops and athletic venues as a dietary supplement and purported to induce sleep, release growth hormone, enhance sexual activity and athletic performance, there is no recognized therapeutic indication for GBL. However, it has widespread industrial use being a common solvent found in paint strippers, nail polish removers, stain removers and circuit board cleaners. It is also a common intermediate in industrial chemistry including in the manufacture of pyrrolidones and in some pharmaceuticals.
Recommendation
GBL produces its effects in the body through the in vivo formation of the scheduled substance GHB. The Committee considered that the degree of risk to public health and society associated with the abuse liability of GBL is especially serious. While the Committee recognized widespread and important industrial use, GBL has no defined therapeutic usefulness. The Committee considered that the evidence of its abuse warranted its placement under international control within Schedule I of the 1971 Convention.
Gamma-butyrolactone (GBL) is chemically oxolan-2-one. GBL can be synthesized from ɤ-hydroxybutyric acid (GHB) or tetrahydrofuran.
Previous review
During the pre-review of GHB at the thirty-fourth meeting of the ECDD, the Committee "noted information relating to the abuse of GBL itself (convertible to GHB in the body) and suggested this substance for pre-review". Based on the evidence presented in the pre-review of GBL during the thirty-fifth meeting of the ECDD, given its close association with GHB, and the recommendation made by the Committee at its thirty-fifth meeting to reschedule GHB from Schedule IV to Schedule II of the 1971 Convention, the Committee recommended that a critical review of GBL be undertaken.
Similarity to known substances and effects on the central nervous system
GBL is readily converted, both chemically and in the body, to the Schedule II drug GHB and most of GBL’s pharmacological and toxicological effects are mediated through GHB as a metabolite. Nevertheless, pharmacological factors show that GBL tends to be more potent, faster acting and to have a longer duration of activity than GHB. It is a central nervous system depressant with effects that are exacerbated by other central nervous system depressants (including ethanol). There is a steep dose–effect curve between doses producing desired and excessive effects, and there have been numerous published reports of adverse reactions to GBL including fatalities. Signs and symptoms include euphoria, relaxation, reduced inhibition and sedation, progressing to vomiting, urinary and faecal incontinence, agitation, convulsions, bradycardia, respiratory depression, coma and death.
Dependence potential
Reports of animal studies noted a spontaneous and precipitated withdrawal syndrome after chronic administration of GBL. There have been various reports that, in human users, GBL can produce a withdrawal syndrome when the substance is abruptly discontinued following regular chronic use. Withdrawal from GBL appears similar to withdrawal from other sedative–hypnotic drugs such as ethanol and benzodiazepines.
Actual abuse and/or evidence of likelihood of abuse
GBL abuse and/or seized material have been reported in 18 countries. GBL is sold as a liquid, often presented for illicit sale as GHB but also as a so-called cleaning product via the Internet. It is extremely difficult to accurately assess the magnitude of abuse relating specifically to GBL considering the near absence of data explicitly pertaining to GBL rather than GHB or 1,4-butanediol.
Therapeutic usefulness
While GBL was sold in health food shops and athletic venues as a dietary supplement and purported to induce sleep, release growth hormone, enhance sexual activity and athletic performance, there is no recognized therapeutic indication for GBL. However, it has widespread industrial use being a common solvent found in paint strippers, nail polish removers, stain removers and circuit board cleaners. It is also a common intermediate in industrial chemistry including in the manufacture of pyrrolidones and in some pharmaceuticals.
Recommendation
GBL produces its effects in the body through the in vivo formation of the scheduled substance GHB. The Committee considered that the degree of risk to public health and society associated with the abuse liability of GBL is especially serious. While the Committee recognized widespread and important industrial use, GBL has no defined therapeutic usefulness. The Committee considered that the evidence of its abuse warranted its placement under international control within Schedule I of the 1971 Convention.
ECDD Recommendation
Inclusion in Schedule I of the 1971 Convention on Psychotropic Substances
Link to full TRS
who_trs_991_eng.pdf1.3 MB
MS Questionnaire Report