GBL

There is a high incidence of death due to respiratory depression when GABAergic substances are combined with depressants such as opiates, benzodiazepines or alcohol.

GBL
The skeletal formula of GBL
Chemical Nomenclature
Common names	GBL, gamma-Butyrolactone
Substitutive name	1,4-lactone, 4-butyrolactone, 4-hydroxybutyric acid lactone, gamma-hydroxybutyric acid lactone, and oxolan-2-one
Systematic name	Dihydrofuran-2(3H)-one
Class Membership
Psychoactive class	Depressant
Chemical class	GABAergic
Routes of Administration
Oral Dosage WARNING: Always start with lower doses due to differences between individual body weight, tolerance, metabolism, and personal sensitivity. 1 - 3mls dissolved in 500mls of water. Presumes no tolerance. Duration Total 1.5 - 2.5 hours Onset 10 - 30 minutes Peak 45 - 90 minutes Offset 15 - 30 minutes Afterglow 2 - 4 hours

Summary sheet: GBL

GBL (γ-butyrolactone or gamma-Butyrolactone) is a hygroscopic colorless oily liquid with a weak characteristic odor and is soluble in water. GBL is a common solvent and reagent in chemistry and is used as a flavouring, as a stain remover, as a wheel cleaner, as a superglue remover, as a paint stripper, and as a solvent in some wet aluminium electrolytic capacitors.

In terms of its natural sources, GBL has been found in extracts from samples of unadulterated wines. This finding indicates that GBL is a naturally occurring component in some wines and may be present in similar products. The concentration detected was approximately 5 μg/mL and was easily observed using a simple extraction technique followed by GC/MS analysis. It can also be found in cheese flavourings but typically results in a content of 0.0002% GBL in the final foodstuff.

In humans it acts as a prodrug for GHB, where 1ml is equivalent to 1.66 grams of GHB. It is used as a recreational intoxicant with effects similar to alcohol.

Chemistry

GBL, or 1,4-lactone, is a cyclic ester of hydroxybutanoic acid. GBL can be synthesized from GHB through dehydration of the terminal hydroxy groups, forming a cyclic structure with an oxygen substituent. Structurally, GBL is a five-membered ring with an oxygen substituent adjacent to the R₁ carbonyl group, forming a cyclic ester called a lactone.

Pharmacology

Main article: GHB § Pharmacology

GBL is not active in its own right; its mechanism of action stems from its identity as a prodrug of GHB.

It is rapidly converted into GHB by lactonase enzymes found in the blood. GBL is more lipophilic (fat soluble) than GHB, and so is absorbed faster and has higher bioavailability; the paradox is that this can mean that GBL has a faster onset of effects than GHB itself, even though it is a prodrug.

The levels of lactonase enzyme can vary between individuals, meaning that first-time users can show unpredictable results, even from small doses. In many this manifests as slow onset of effects, followed by headaches, semi-consciousness which is distinct from GBL sleep in normal users. If the user decides to try again at a later date, they appear to be able to enjoy the effects normally. Because of these pharmacokinetic differences, GBL tends to be more potent and faster-acting than GHB, but has a shorter duration; whereas the related compound 1,4-butanediol (1,4-B) tends to be slightly less potent, slower to take effect but longer-acting than GHB.

Subjective effects

The effects listed below are based upon the subjective effects index and personal experiences of PsychonautWiki contributors. The listed effects will rarely (if ever) occur all at once, but heavier dosages will increase the chances and are more likely to induce a full range of effects.

Physical effects

• Stimulation and Sedation - At lower dosages, GBL is physically stimulating, encouraging movement and wakefulness. At higher dosages, however, it becomes physically sedating, encouraging sleep and lethargy.
• Respiratory depression - In cases of GBL overdoses, many reportedly experience an abnormal pattern of breathing characterized by progressively deeper and sometimes faster breathing, followed by a gradual decrease that results in a temporary stop in breathing called an apnea.
• Euphoria
• Nausea
• Motor control loss
• Dizziness
• Dehydration

Cognitive effects

• Empathy, love and sociability enhancement - Unlike alcohol which merely increases sociability through disinhibition, GBL presents strong entactogenic effects which although weaker than that of MDMA are still prominent and well defined.
• Disinhibition
• Information processing suppression
• Thought deceleration
• Amnesia
• Euphoria
• Anxiety suppression

Toxicity and harm potential

Main article: GHB § Toxicity and harm potential

Radar plot showing relative physical harm, social harm, and dependence of GHB

GBL is not active in its own right; its mechanism of action stems from its identity as a prodrug of GHB, meaning that it is rapidly converted into GHB in the body.

GHB/GBL is considered to be a safe and non-toxic substance when used responsibly or medically. The LD50 is above the active dosage, and there is no danger of acute toxicity. However, it can be dangerous when used as a recreational drug or abused. There have been many negative reports from recreational users who have overdosed, combined GHB/GBL with alcohol or other drugs, or accidentally dosed themselves unexpectedly.

One publication has investigated 226 deaths attributed to GHB. Seventy-one deaths (34%) were caused by GHB alone while the other deaths were from respiratory depression caused by interaction with alcohol or other drugs.

To avoid a possible overdose of GBL, it is important to start with a low dose and work your way up slowly by increasing the dosage in small increments.

Accidental ingestions of GBL have also occurred due to inadequate storage methods. If GBL is put into a clear liquid, glass, or bottle, it can be easily mistaken for water. It is recommended to clearly label your GBL in writing and dye the liquid with blue food coloring so it no longer resembles a drinkable beverage. It is also recommended to store your GBL in a container that no one would drink out of.

Tolerance and addiction potential

Frequent use of GBL (even when taken long-term and in moderate doses) does not appear to cause significant physical dependency in the greater majority of its users. In many people, quitting or temporarily abstaining from use of the drugs is achieved with minimal or no difficulty. However, when consumed in excessive amounts with a high frequency of dosing, physical and psychological dependence can develop.

For those users who do report withdrawal symptoms upon quitting the use of GBL, symptoms seem to depend on the dosage and the length of time the drug was used for. Light to moderate users often experience insomnia and sleep-related problems, whereas heavy, prolonged use can cause severe withdrawal symptoms similar to benzodiazepine withdrawal syndrome (BWS).

Dangerous interactions

Although many drugs are safe on their own, they can become dangerous and even life-threatening when combined with other substances. The list below contains some common potentially dangerous combinations, but may not include all of them. Certain combinations may be safe in low doses of each but still increase the potential risk of death. Independent research should always be done to ensure that a combination of two or more substances is safe before consumption.

• Depressants (1,4-Butanediol, 2-methyl-2-butanol, alcohol, barbiturates, benzodiazepines, GHB, methaqualone, opioids) - This combination can result in dangerous or even fatal levels of respiratory depression. A review of the details of 194 deaths attributed to or related to GHB over a ten-year period found that most were from respiratory depression caused by interaction with alcohol or other drugs. In humans, GHB has been shown to inhibit the elimination rate of alcohol. This may explain the respiratory arrest that has been reported after ingestion of both drugs. These substances also potentiate the muscle relaxation, sedation and amnesia caused by one another and can lead to unexpected loss of consciousness at high doses. There is also an increased risk of vomiting during unconsciousness and death from the resulting suffocation. If this occurs, users should attempt to fall asleep in the recovery position or have a friend move them into it.
• Dissociatives - This combination can result in an increased risk of vomiting during unconsciousness and death from the resulting suffocation. If this occurs, users should attempt to fall asleep in the recovery position or have a friend move them into it.
• Stimulants - It is dangerous to combine GBL, a depressant, with stimulants due to the risk of excessive intoxication. Stimulants decrease the sedative effect of GBL, which is the main factor most people consider when determining their level of intoxication. Once the stimulant wears off, the effects of GHB will be significantly increased, leading to intensified disinhibition as well as other effects. If combined, one should strictly limit themselves to only dosing a certain amount of GHB per hour. This combination can also potentially result in severe dehydration if hydration is not monitored.

Legal issues

• Australia: GBL is a border controlled substance and is illegal to import into Australia without a permit. The importation of a commercial quantity of a border controlled drug (over 1 kg of GBL) is punishable by up to life imprisonment and/or an $825,000 fine.
• Canada: GBL is a Controlled Substance under Schedule VI of the "Controlled Drugs and Substances Act" in Canada. Schedule VI of the "Controlled Drugs and Substances Act" requires vendors to collect information regarding purchases of GBL. The Act also prohibits the import and export of GBL into or out of Canada classifying it as either an indictable offence punishable with up to 10 years in prison or an offence punishable on summary conviction liable to imprisonment for up to eighteen months. It is not illegal for an individual to possess GBL in Canada.
• Germany: GBL is not listed in the narcotics law, but its distribution is controlled. Possession is not illegal, but may be punished according to the Medicines Act, when intended to be sold for human consumption or synthesis of GHB. In recent years, an increase of GBL consumption has been observed due to the prohibition of GHB.
• Hong Kong: GBL is a dangerous drug controlled under Schedule 1 of the Dangerous Drugs Ordinance, Cap.134 (with exemption clause at Paragraph 16D). Any person who is found to have in his possession of it not in accordance with this Ordinance can be liable, on conviction upon indictment, a fine of HK$1,000,000 and to imprisonment for 7 years.
• Israel: GBL was classified as a proscribed substance from 2007.
• Netherlands: GBL can be freely bought as a cleaning agent. Retailers do not need a licence to sell the substance.
• Poland: GBL is not classified as a drug and can be purchased in chemistry shops as a solvent.
• Sweden: GBL is not classified as a drug but as a health-endangering substance. Although recently passed legislation to enter into force on 1 April 2011 will make it possible to handle narcotics for industrial purposes will enable GBL and 1,4-Butanediol to be classified as controlled substances.
• United Kingdom: Because of their legitimate uses, regulation 4B of the 2001 regulations makes it lawful to import, export, produce, supply, offer to supply or possess GBL and 1,4-BD. Except where a person does so knowing or believing that they will be used for the purpose of human ingestion.
• United States: GBL is regulated as a List 1 controlled chemical. As a GHB analog, it is treated as a controlled substance under Schedule I of the "Controlled Substances Act" if intended for human consumption.

See also

• Responsible use
• GBL (Wikipedia)
• Depressants
• GHB