GBL Stats & Data

GBL has a long history as an industrial chemical, primarily valued as a solvent and intermediate in the synthesis of other compounds. Its commercial applications have included use as a flavoring agent, stain remover, wheel cleaner, paint stripper, superglue remover, and as a solvent in certain wet aluminum electrolytic capacitors. The recreational history of GBL is closely intertwined with the scheduling of GHB. Following restrictions placed on GHB, GBL was marketed as a nutritional supplement under brand names such as Revivarant and Renewtrient, capitalizing on its property as a GHB prodrug that enhances sleep-related growth hormone secretion. These products were eventually prohibited by the FDA. In response to tightening regulations on both substances, home synthesis kits emerged that enabled users to convert GBL and 1,4-butanediol into GHB, effectively circumventing restrictions on the scheduled substance. The relative accessibility of GBL's precursors has contributed to its popularity in certain recreational contexts, particularly among young people in French nightclub scenes where it can be produced with readily available materials. Both GBL and GHB are colloquially referred to as "K.-o.-Tropfen" (knockout drops) in German-speaking countries. While concerns have been raised regarding the potential use of GBL as a drug-facilitated sexual assault agent—particularly as an alternative to scheduled GHB—the available evidence suggests such use is not widespread, especially when compared to alcohol, partly due to GBL's distinctively strong taste.

Forked from Subjective Effect Documentation by Josie Kins, September 2015. Via dose.wiki (CC0).

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. GBL is not considered to be as safe as GHB used responsibly or medicinally, since it is theorized to display additional toxic effects on the body in difference to GHB. The LD50 is above the active dosage, and there is no danger of acute toxicity. However, it can become dangerous when used as a recreational drug, abused, or in combination with other drugs. There have been many negative reports from recreational users who have overdosed, combined GBL with alcohol or other drugs, or accidentally dosed themselves unexpectedly or way above the common dosage range.

Effects aggregated from 42 experience reports (42 single-substance Erowid)

Each bar is the share of reports mentioning the effect; its whisker, and the band on the rows below, is the 95% interval: where the share could plausibly be with other reports of the same kind.

Also reported in combinations. In the 38 GBL reports where another drug was taken too, 10 (26.3%) mention hospital, emergency services or an overdose, 3 (7.9%) a seizure and 2 (5.3%) psychosis. In the 42 single-substance reports: 26.2%, 7.1% and 9.5%. These are not in the figures above: they cannot be put down to GBL alone, and a mention is not always something that happened to the writer.

Dose distribution from experience reports, one dose per report (the first listed). Doses above Q3 + 3×IQR, far above what people typically take, are left out of the median and range and listed under each route: most are real heavy doses or overdoses, not mistakes.

From 9 of 71 recorded dose entries: those that state a weight (mg, g or µg), in routes with at least five of them. Values above Q3 + 3×IQR, far above what people typically take, are left out; they can include real heavy doses and overdoses, not only mistakes.

Most co-occurring substances, as a share of all 80 reports filed under GBL; whiskers are 95% intervals

Most common forms and preparations, as a share of the 52 reports that give one; whiskers are 95% intervals

Redosing behavior across 65 reports