GBL
G · gamma-butyrolactone
What is currently changing about this drug in the UK?
GBL is widely encountered in UK chemsex and sexualised drug-use settings and is rapidly converted to GHB in the body. GHB is also reported, and many UK datasets group GHB and GBL together, so the precise substance used or sold is not always distinguishable. A Home Office consultation published on 19 August 2026 proposes tighter controls; current law remains unchanged pending the outcome and any subsequent legislation.
Overview
Identity, legal classification, form and pharmacological context
- Drug category
- Depressants · Synthetic drugs
- Common names
- G, gamma-butyrolactone
- Typical forms
- Usually a colourless liquid; sold identity and concentration may be uncertain
- Routes
- Swallowed, commonly after careful dilution
- UK legal classification
- Class BControlled for human ingestion; legitimate industrial-use provisions apply.Check government source ↗
- Concise pharmacology
- GBL is rapidly converted in the body to GHB, which acts mainly at GABA-B receptors and produces dose-dependent central nervous system depression.
Main harms
Concise clinical and polydrug picture
Impaired coordination, reduced consciousness, vomiting and breathing problems, especially in combinations.
Cognitive, physical and mental-health harms vary by substance and pattern of use.
Abrupt withdrawal from some depressants can be severe and requires clinical assessment.
Alcohol, opioids, benzodiazepines and other depressants substantially increase severe-sedation and breathing risks.
Small differences in liquid dose or concentration can cause rapid loss of consciousness. Combining GBL or GHB with alcohol or other depressants substantially increases risk.
Current intelligence status
Assessment, confidence and direction
The assessment reflects the latest linked evidence and is not a universal severity rating.
Operational implications
Evidence-supported prompts for professional response
Use GBL/GHB-specific overdose and withdrawal pathways, make dose uncertainty explicit and distinguish the consultation from current law.
Record substance, sold identity, route, frequency and combinations; review overdose and withdrawal needs.
Use symptom-led assessment and escalate reduced consciousness, seizures, overheating, chest pain or severe agitation.
Triangulate treatment, mortality, testing, hospital and frontline evidence before assigning a local trend.
Related intelligence
Continue into connected platform evidence
Sources & limitations
Direct evidence links, reference periods and status
Deaths related to drug poisoning in England and Wales
Published17 Oct 2025Reference period2024 registrations
Deaths are counted by registration year; substance mentions overlap and do not prove sole causation.Adult substance misuse treatment statistics
Published04 Dec 2025Reference periodEngland · 2024–25
Treatment contact reflects recorded service need and access in England, not population prevalence.Control of Gamma-Butyrolactone and 1,4-Butanediol
Published19 Aug 2026Reference periodConsultation closes 11 Nov 2026
The proposals are not law. Current law remains unchanged pending the outcome and any subsequent legislation.