gamma-Hydroxybutyric acid or γ-Hydroxybutyric acid (GHB), also known as 4-hydroxybutanoic acid, is a naturally occurring neurotransmitter and a psychoactive drug. It is a precursor to GABA, glutamate, and glycine in certain brain areas. It acts on the GHB receptor and is a weak agonist at the GABAB receptor. GHB has been used in the medical setting as a general anesthetic and as a treatment for cataplexy, narcolepsy, and alcoholism.It is also used illegally as an intoxicant, as an athletic performance enhancer, as a date rape drug, and as a recreational drug.
It is commonly used in the form of a salt, such as sodium γ-hydroxybutyrate (NaGHB, sodium oxybate, or Xyrem) or potassium γ-hydroxybutyrate (KGHB, potassium oxybate). GHB is also produced as a result of fermentation, and is found in small quantities in some beers and wines, beef and small citrus fruits.
GHB is used for medical purposes in the treatment of narcolepsy and, more rarely, alcoholism, although its use for alcoholism is not supported by evidence from randomized controlled trials. It is sometimes used off-label for the treatment of fibromyalgia. GHB is the active ingredient of the prescription medication sodium oxybate (Xyrem). Sodium oxybate is approved by U.S. Food and Drug Administration for the treatment of cataplexy associated with narcolepsy and excessive daytime sleepiness (EDS) associated with narcolepsy.
GHB has been shown to reliably increase slow-wave sleep and decrease the tendency for REM sleep in modified multiple sleep latency tests.
GHB powderDelphic analysis of harm assessment for 20 popular recreational drugs (conducted by David Nutt and his colleagues at University of Bristol in 2007) ranks (in decreasing order of harmfulness) GHB 15th in dependence, 19th in physical harm, and 14th in social harm.
GHB is a central nervous system depressant used as an intoxicant. It has many street names. Its effects have been described anecdotally as comparable with ethanol (alcohol) and MDMA use, such as euphoria, disinhibition, enhanced libido and empathogenic states. A review comparing ethanol to GHB concluded that the dangers of the two drugs were similar. At higher doses, GHB may induce nausea, dizziness, drowsiness, agitation, visual disturbances, depressed breathing, amnesia, unconsciousness, and death. One potential cause of death from GHB consumption is polydrug toxicity. Co-administration with other CNS depressants such as alcohol or benzodiazepines can result in an additive effect (potentiation), as they all bind to gamma-aminobutyric acid (or “GABA”) receptor sites. The effects of GHB can last from 1.5 to 4 hours, or longer if large doses have been consumed.Consuming GHB with alcohol can cause respiratory arrest and vomiting in combination with unrousable sleep, which can contribute to a lethal outcome.
Recreational doses of 1–2 g generally provide a feeling of euphoria, and larger doses create deleterious effects such as reduced motor function and drowsiness. The sodium salt of GHB has a salty taste. Other salt forms such as calcium GHB and magnesium GHB have also been reported,but the sodium salt is by far the most common.
Some prodrugs, such as γ-butyrolactone (GBL), convert to GHB in the stomach and blood stream. Other prodrugs, such as 1,4-butanediol (1,4-B), have their own toxicity concerns. GBL and 1,4-B are normally found as pure liquids, but they can be mixed with other more harmful solvents when intended for industrial use (e.g. as paint stripper or varnish thinner).
GHB can be manufactured with little knowledge of chemistry, as it involves the mixing of its two precursors, GBL and an alkali hydroxide such as sodium hydroxide, to form the GHB salt. Due to the ease of manufacture and the availability of its precursors, it is not usually produced in illicit laboratories like other synthetic drugs, but in private homes by low-level producers.
GHB is “colourless and odourless”.
A 2006 report commissioned by a UK parliamentary committee found the use of GHB to be less dangerous than tobacco and alcohol in physical harm, dependence and social harms.