GBL Facts
Depressant;
Description
GBL (gamma-butyrolactone) — G, liquid ecstasy — is a synthetic depressant of the lactone class. It is a prodrug of GHB: the body converts it to GHB within minutes, and GHB produces every effect. GHB activates inhibitory receptors in the brain, broadly suppressing neural activity and producing sedation.
Subjective effects include euphoria, disinhibition, empathogenic warmth, sexual arousal, and sedation. The experience rises to full effect in minutes — a steep rush that compresses what alcohol spreads over hours — then tips abruptly into deep unconsciousness with only a small dose increase.
GBL produces physical dependence faster than alcohol or benzodiazepines,[1] and a fraction of a milliliter separates a recreational dose from one that stops breathing. Compulsive redosing accelerates dependence within days, and withdrawal carries real risk of seizures and death.
Dose and durationby route · individual sensitivity varies
Starts in 3 – 10 minLasts 1 – 2 hoursAfter-effects 1 – 3 hours
Body and dependence
- Acute toxicity
- High
- Chronic toxicity
- Moderate
- Physical dependence
- High
- Psychological dependence
- High
- Withdrawal
- Life-threatening · fatal · medical supervision
- Compulsive redosing
- High
Tolerance
- Builds
- Rapid
- Fully resets after
- 10.5 days
- Carries over to
- GHB;
1,4-butanediol
Effectslikely at a common dose
- Perception
- none likely · 10 possible, including Spatial disorientation, Vestibular distortion, Visual acuity suppression
- Body
- Motor control impairment;
Muscle relaxation; Sedation; +15 possible, including Dizziness, Nausea, Nystagmus (eye wobbles) - Thinking
- none likely · 17 possible, including Cognitive impairment, Decision impairment, Analysis suppression
- Feeling
- none likely · 6 possible, including Emotional lability
- Self
- Disinhibition;
+7 possible, including Craving, Communication suppression - Time
- none likely · 2 possible, including Temporal disorientation
Who shouldn't take it
Combinations64 recorded
Seek help immediately if
- Extreme drowsiness — can't stay awake or be roused
- Confusion, slurred speech, severe loss of coordination
- Slow, shallow, or irregular breathing
- Unconsciousness / unresponsive; limp, floppy body
- Blue lips or fingertips
- Vomiting while sedated (choking / aspiration risk)
- Cold, clammy skin; weak pulse
What to do
- Try to wake them — shout, firm sternal rub
- If unresponsive or breathing is impaired, call emergency services
- Place them in the recovery position — critical, they can choke on vomit
- Monitor breathing continuously; be ready to give rescue breaths / CPR
- Never leave them alone to "sleep it off"
- Do not give other drugs, stimulants, or more depressants
Most depressant overdoses resolve with airway protection, breathing support, and monitoring. The danger is respiratory depression and choking on vomit — sharply worse when combined with opioids or alcohol. GHB/GBL overdoses often involve sudden deep unconsciousness and may self-resolve, but airway protection is essential.
988 Suicide & Crisis LifelineFireside Project: 62-FIRESIDE
References
- [1]^Schep LJ, Knudsen K, Slaughter RJ, Vale JA, Megarbane B (2012) The clinical toxicology of gamma-hydroxybutyrate, gamma-butyrolactone and 1,4-butanediol — Clinical Toxicology doi:10.3109/15563650.2012.702218