data + articles · 2 listed
newest 2023spec sheet10 rows
GBL (gamma-butyrolactone) is an industrial solvent and a prodrug for GHB; once swallowed the body rapidly converts it to GHB, so it produces the same euphoria, disinhibition, and sedation. It's oily, extremely potent by volume, and absorbed faster than GHB itself. The overdose margin is frighteningly narrow, and mixing with alcohol is a well-known cause of death.
- Euphoria and sociability
- Relaxation
- Short duration
- Very narrow dose margin
- Sudden loss of consciousness
- Respiratory depression
- Severe dependence and withdrawal
Mechanism
GBL itself is largely inactive; enzymes (lactonases) in the blood quickly convert it to GHB (gamma-hydroxybutyrate). GHB acts as an at GHB-specific receptors and, at recreational doses, as a weak agonist at -B receptors, producing central nervous system depression. Because GBL is more lipid-soluble and converts rapidly, it acts faster and is effectively more potent by volume than an equal measure of GHB, which makes dose control extremely difficult.
receptor fingerprint
GHB receptorAgonist (via GHB after conversion)
-B receptorWeak agonist (via GHB after conversion)
Safetyrisks and cautions, not medical advice
The dose-response curve is brutally steep; a small extra amount can flip pleasant effects into unconsciousness, vomiting, and dangerously slowed breathing. Combined with alcohol or other depressants the risk of respiratory arrest and death rises steeply, and people can slip into a coma very quickly. Regular use causes rapid physical dependence with a severe, potentially life-threatening withdrawal (agitation, insomnia, delirium) needing medical care. GBL is also caustic and should never be handled undiluted near skin or mouth. Not medical advice.
Subjective profileweighing the evidence above
Avoid entirely. It converts to GHB with a dose margin narrow enough that a small measuring error means unconsciousness and slowed breathing, alcohol makes that combination lethal, and regular use produces a withdrawal that can kill without medical care. It is caustic in the bottle on top of all that.
Resources
This entry is here for reference.
Research
- 1.Gamma-hydroxybutyrate (GHB), 1,4-butanediol (1,4BD), and gamma-butyrolactone (GBL) intoxication: A state-of-the-art review.
- 2.Management and treatment of gamma butyrolactone withdrawal syndrome: a case report and review.
2 listed here; entry last updated July 2026
Reviews
My notesprivate to this device
FAQ
How is GBL related to GHB?
GBL is a prodrug; the body converts it into GHB, so the effects are essentially those of GHB but with a faster onset and greater potency by volume.
Why is it so easy to overdose?
The gap between a recreational dose and one causing unconsciousness or coma is tiny, and it's worsened dramatically by alcohol.
Is withdrawal dangerous?
Yes. Regular use causes fast dependence, and withdrawal can be severe and life-threatening, resembling delirium tremens; it needs medical management.
Adverse effects
- Very narrow dose margin
- Sudden loss of consciousness
- Respiratory depression
- Severe dependence and withdrawal