What are GHB / GBL / 1,4-BD?

GHB (Gamma hydroxybutyrate) is an anaesthetic with primarily sedating rather than painkilling properties. It is often sold as ‘liquid ecstasy’ because of its relaxant and euphoric effects, although it has no relationship to ecstasy.


GBL (Gamma butyrolactone) and 1,4-BD (1,4-butanediol) are chemicals that are closely related to GHB. Once GBL or 1,4-BD enter the body, they convert to GHB very quickly.

GHB, GBL and 1,4-BD are clear, odourless, oily liquids that taste slightly salty. Users often swallow them mixed with water or other soft drinks. When intended for illicit use, GHB, GBL and 1,4-BD are sold in small bottles or capsules. However, as solvents, GBL and 1,4-BD do have legitimate uses, for example in some paint strippers and stain removers.


There is very little statistical evidence relating to the prevalence of GHB, GBL and 1,4-BD in the UK. The drugs do not feature in any of the major national surveys of recreational drug use, such as the British Crime Survey Drug Misuse Declared bulletin.

Anecdotal evidence suggests that use of the drugs is fairly widespread on the UK club scene, particularly in gay clubs, but have yet to become significant players among the general drug-taking population (1).

The law

In November 2020 the Advisory Council on the Misuse of Drugs advised that GHB should become a Class B drug rather than Class C – see Assessment of the harms of gamma-hydroxybutyric acid, gamma-butyrolactone, and closely related compounds – November 2020. Advisory Council on the Misuse of Drugs

In March 2021 Home Secretary Priti Patel said GHB would now move from a Class C to a Class B drug. The Home Office said associated substances GBL and 1,4-BD – which convert to GHB in the body – would also be moved into Class B. It added that, in future, the law would require a licence for anyone wishing to possess the associated substances for “legitimate” purposes.


GHB and GBL are depressant drugs which can produce a mild high in smaller doses and sedation in higher doses. Users of GHB/GBL and 1,4-BD report that the drugs make them feel euphoric, with a loss of inhibitions, increased confidence and higher libido. Some people liken the experience to taking ecstasy, although most users report that the experience is very similar to being drunk on alcohol.

GHB was developed in the USA as a pre-medication to help patients sleep before surgery. Some people who use the drug illicitly do so not for the euphoric effects, but rather use higher doses to help them sleep. As GHB/GBL and 1,4-BD help promote ‘slow wave sleep’, during which growth hormone is secreted, the substances have also been used by bodybuilders.

The sedative properties of GHB and its related compounds, as well as their neutral odour and taste have led some to link the drugs to instances of drug-facilitated sexual assault, although the extent of the drugs’ use in these crimes remains unclear. A 2006 study by the Association of Chief Police Officers (ACPO) found that of 120 instances of alleged drug-facilitated sexual assault, only two victims had tested positive for GHB.

It is very easy to overdose on these drugs, both because the strength can vary from bottle to bottle and because the doses involved are measured in such small quantities – the difference between a recreational dose and overdose may only be a matter of millilitres.

Overdosing on GHB/GBL or 1,4-BD can be very dangerous. Nausea and vomiting, seizures, convulsions, disorientation and stiffening of muscles may occur, and coma and respiratory collapse may follow.

Evidence is emerging that shows it is possible to become physically dependent on GHB and GBL/1,4-BD. While this does seem to be quite rare, when someone develops a dependency it can be severe, with a rapid onset of unpleasant withdrawal symptoms which may include delirium, psychosis, tremor, insomnia and severe anxiety.

Dependence can develop fairly quickly, for example after a weekend of severe bingeing on GHB and its related compounds, or may result from regular use over a longer period. Doctors are currently treating withdrawal from GHB-type drugs with benzodiazepines, although further research is needed into other treatments.

DrugWatch Information Sheet GBL 

Assessment of the harms of gamma-hydroxybutyric acid, gamma-butyrolactone, and closely related compounds – November 2020. Advisory Council on the Misuse of Drugs