Herb & supplement monograph

Gamma Butyrolactone (gbl) Drug Interactions, Uses, Effectiveness, Safety & More

Medically reviewed by ·Updated July 2026
What is this page for?

First and foremost: how Gamma Butyrolactone (gbl) interacts with medications. The heart of this page is the interaction list — every drug Gamma Butyrolactone (gbl) is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Gamma Butyrolactone (gbl) is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

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Gamma Butyrolactone (gbl) Drug Interactions: The Bottom Line

From the HelloPharmacist Editorial Team · Updated July 2026

Based on the available evidence, Gamma Butyrolactone (gbl) drug interactions carry a moderate but real risk for many people, especially anyone who drinks alcohol or takes sedating medicines. Every listed interaction is rated moderate in severity, and while most rest on limited human reports, several involve dangerous slowing of breathing.

Interactions deserving the most attention

GBL is converted in the body to GHB, a strong sedative, so combining it with anything else that slows the brain raises the stakes. The pairings we would watch most closely are alcohol, which can add to sedation and slow the body's clearance of GHB, and narcotic pain medicines, where one reported case involving heroin was fatal. The HIV medicines ritonavir and saquinavir also stand out, since a near-fatal reaction was reported when they blocked GHB breakdown. Certain seizure medicines, including topiramate and divalproex, may raise GHB levels or affect seizure control.

What the rest of the list means

Most of the long list reflects broad categories of sedating drugs, grouped together because of a shared theoretical risk rather than proof of harm for each one. The evidence is largely from case reports and predicted effects, not controlled studies, but the pattern of concern with sedation is consistent enough to take seriously.

Check your medications against Gamma Butyrolactone (gbl)

Based on HelloPharmacist’s Gamma Butyrolactone (gbl) interaction data and reviewed under our editorial standards.

Interaction report

Drugs that interact with Gamma Butyrolactone (gbl)

271 medications have a known interaction with Gamma Butyrolactone (gbl), graded by severity. Select any drug for the full evidence-based detail.

2,830 drugs
AcepromazineAtravet
Moderate Cns Depressants

Theoretically, concomitant use of GBL with CNS depressants may potentiate respiratory and CNS depression.

Read the full Gamma Butyrolactone (gbl) + Acepromazine interaction
Acetaminophen, Butalbital, Caffeine, CodeineEsgic with Codeine, Fioricet w/ Codeine
Moderate Cns Depressants

Theoretically, concomitant use of GBL with CNS depressants may potentiate respiratory and CNS depression.

Read the full Gamma Butyrolactone (gbl) + Acetaminophen, Butalbital, Caffeine, Codeine interaction
Acetaminophen, Butalbital, CodeineBancap w/ Codeine
Moderate Narcotic Drugs

Theoretically, concomitant use of GBL with narcotic drugs may potentiate respiratory and central nervous system (CNS) depression.

Read the full Gamma Butyrolactone (gbl) + Acetaminophen, Butalbital, Codeine interaction
Acetaminophen, Butalbital, Codeine PhosphatePhrenilin #3
Moderate Cns Depressants

Theoretically, concomitant use of GBL with CNS depressants may potentiate respiratory and CNS depression.

Read the full Gamma Butyrolactone (gbl) + Acetaminophen, Butalbital, Codeine Phosphate interaction
Acetaminophen, Caffeine, Chlorpheniramine, Hydrocodone, PhenylephrineHycomine Compound
Moderate Narcotic Drugs

Theoretically, concomitant use of GBL with narcotic drugs may potentiate respiratory and central nervous system (CNS) depression.

Read the full Gamma Butyrolactone (gbl) + Acetaminophen, Caffeine, Chlorpheniramine, Hydrocodone, Phenylephrine interaction
Acetaminophen, Caffeine, CodeineGesic C15, Gesic C30, Gesic C8, Lenoltec 1, Lenoltec 2, Lenoltec 3 +1 more
Moderate Cns Depressants

Theoretically, concomitant use of GBL with CNS depressants may potentiate respiratory and CNS depression.

Read the full Gamma Butyrolactone (gbl) + Acetaminophen, Caffeine, Codeine interaction
Acetaminophen, Caffeine, Codeine, SalicylamideCodalan No.1, Codalan No.2, Codalan No.3
Moderate Narcotic Drugs

Theoretically, concomitant use of GBL with narcotic drugs may potentiate respiratory and central nervous system (CNS) depression.

Read the full Gamma Butyrolactone (gbl) + Acetaminophen, Caffeine, Codeine, Salicylamide interaction
Acetaminophen, Caffeine, DihydrocodeineDHC Plus, Panlor DC, Panlor SS
Moderate Cns Depressants

Theoretically, concomitant use of GBL with CNS depressants may potentiate respiratory and CNS depression.

Read the full Gamma Butyrolactone (gbl) + Acetaminophen, Caffeine, Dihydrocodeine interaction
Acetaminophen, Chlorpheniramine, Codeine, PhenylephrineColrex
Moderate Narcotic Drugs

Theoretically, concomitant use of GBL with narcotic drugs may potentiate respiratory and central nervous system (CNS) depression.

Read the full Gamma Butyrolactone (gbl) + Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine interaction
Acetaminophen, Chlorpheniramine, Phenylpropanolamine, OpiumHista-Derfule
Moderate Cns Depressants

Theoretically, concomitant use of GBL with CNS depressants may potentiate respiratory and CNS depression.

Read the full Gamma Butyrolactone (gbl) + Acetaminophen, Chlorpheniramine, Phenylpropanolamine, Opium interaction
Acetaminophen, Chlorzoxazone, CodeineAcetazone Forte C8, Parafon Forte C8
Moderate Narcotic Drugs

Theoretically, concomitant use of GBL with narcotic drugs may potentiate respiratory and central nervous system (CNS) depression.

Read the full Gamma Butyrolactone (gbl) + Acetaminophen, Chlorzoxazone, Codeine interaction
Acetaminophen, CodeineTylenol No.3, Tylenol w/ Codeine
Moderate Cns Depressants

Theoretically, concomitant use of GBL with CNS depressants may potentiate respiratory and CNS depression.

Read the full Gamma Butyrolactone (gbl) + Acetaminophen, Codeine interaction
Acetaminophen, Codeine, DoxylamineMersyndol
Moderate Narcotic Drugs

Theoretically, concomitant use of GBL with narcotic drugs may potentiate respiratory and central nervous system (CNS) depression.

Read the full Gamma Butyrolactone (gbl) + Acetaminophen, Codeine, Doxylamine interaction
Acetaminophen, Codeine, MethocarbamolAcetaminophen, Codeine, Methocarbamol, Robaxacet 8
Moderate Cns Depressants

Theoretically, concomitant use of GBL with CNS depressants may potentiate respiratory and CNS depression.

Read the full Gamma Butyrolactone (gbl) + Acetaminophen, Codeine, Methocarbamol interaction
Acetaminophen, Dichloralantipyrine, IsomethepteneAmidrine, Midchlor, Migquin, Migratine
Moderate Cns Depressants

Theoretically, concomitant use of GBL with CNS depressants may potentiate respiratory and CNS depression.

Read the full Gamma Butyrolactone (gbl) + Acetaminophen, Dichloralantipyrine, Isometheptene interaction
Acetaminophen, Dichloralphenazone, IsomethepteneMidrin
Moderate Cns Depressants

Theoretically, concomitant use of GBL with CNS depressants may potentiate respiratory and CNS depression.

Read the full Gamma Butyrolactone (gbl) + Acetaminophen, Dichloralphenazone, Isometheptene interaction
Acetaminophen, Dichlorophenazone, IsometheptaneIsocom
Moderate Cns Depressants

Theoretically, concomitant use of GBL with CNS depressants may potentiate respiratory and CNS depression.

Read the full Gamma Butyrolactone (gbl) + Acetaminophen, Dichlorophenazone, Isometheptane interaction
Acetaminophen, DiphenhydramineTylenol PM, Tylenol PM Ex Strength
Moderate Cns Depressants

Theoretically, concomitant use of GBL with CNS depressants may potentiate respiratory and CNS depression.

Read the full Gamma Butyrolactone (gbl) + Acetaminophen, Diphenhydramine interaction
Acetaminophen, Diphenhydramine, PseudoephedrineChildren's Tylenol Allergy, Cold Control, Contac Night Allergy Relief
Moderate Cns Depressants

Theoretically, concomitant use of GBL with CNS depressants may potentiate respiratory and CNS depression.

Read the full Gamma Butyrolactone (gbl) + Acetaminophen, Diphenhydramine, Pseudoephedrine interaction
Acetaminophen, HydrocodoneAnexsia, Anodynos DHC, Azdone, Co-Gesic, Doucet, Lorcet +9 more
Moderate Cns Depressants

Theoretically, concomitant use of GBL with CNS depressants may potentiate respiratory and CNS depression.

Read the full Gamma Butyrolactone (gbl) + Acetaminophen, Hydrocodone interaction
Acetaminophen, MeperidineDemerol APAP
Moderate Narcotic Drugs

Theoretically, concomitant use of GBL with narcotic drugs may potentiate respiratory and central nervous system (CNS) depression.

Read the full Gamma Butyrolactone (gbl) + Acetaminophen, Meperidine interaction
Acetaminophen, OxycodonePercocet, Roxicet, Tylox, Xartemis XR
Moderate Cns Depressants

Theoretically, concomitant use of GBL with CNS depressants may potentiate respiratory and CNS depression.

Read the full Gamma Butyrolactone (gbl) + Acetaminophen, Oxycodone interaction
Acetaminophen, PentazocineTalacen
Moderate Narcotic Drugs

Theoretically, concomitant use of GBL with narcotic drugs may potentiate respiratory and central nervous system (CNS) depression.

Read the full Gamma Butyrolactone (gbl) + Acetaminophen, Pentazocine interaction
Acetaminophen, PropoxypheneDarvocet-N 100, Darvocet-N 50, E-Lor, Wygesic
Moderate Cns Depressants

Theoretically, concomitant use of GBL with CNS depressants may potentiate respiratory and CNS depression.

Read the full Gamma Butyrolactone (gbl) + Acetaminophen, Propoxyphene interaction
AcetazolamideAk-Zol, Diamox
Moderate Anticonvulsants

Theoretically, concomitant use of GBL with certain anticonvulsants may potentiate respiratory and central nervous system (CNS) depression or increase the risk of seizures.

Read the full Gamma Butyrolactone (gbl) + Acetazolamide interaction Acetazolamide drug page: uses, dosage & side effects
AlfentanilAlfenta
Moderate Cns Depressants

Theoretically, concomitant use of GBL with CNS depressants may potentiate respiratory and CNS depression.

Read the full Gamma Butyrolactone (gbl) + Alfentanil interaction
AlprazolamNiravam, Xanax
Moderate Cns Depressants

Theoretically, concomitant use of GBL with CNS depressants may potentiate respiratory and CNS depression.

Read the full Gamma Butyrolactone (gbl) + Alprazolam interaction Alprazolam drug page: uses, dosage & side effects
Aluminum Hydroxide, Aspirin, Codeine Phosphate, Magnesium HydroxideAscriptin Codeine #2
Moderate Cns Depressants

Theoretically, concomitant use of GBL with CNS depressants may potentiate respiratory and CNS depression.

Read the full Gamma Butyrolactone (gbl) + Aluminum Hydroxide, Aspirin, Codeine Phosphate, Magnesium Hydroxide interaction
AminoglutethimideCytadren
Moderate Cns Depressants

Theoretically, concomitant use of GBL with CNS depressants may potentiate respiratory and CNS depression.

Read the full Gamma Butyrolactone (gbl) + Aminoglutethimide interaction
Aminophylline, Amobarbital, EphedrineAmesec
Moderate Cns Depressants

Theoretically, concomitant use of GBL with CNS depressants may potentiate respiratory and CNS depression.

Read the full Gamma Butyrolactone (gbl) + Aminophylline, Amobarbital, Ephedrine interaction
Read The List Like a Pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

  • Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
  • Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
  • Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
  • No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

  • Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
  • Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
  • Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

  • Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
  • Each drug listed above links to the full report for that exact Gamma Butyrolactone (gbl) combination — clinical detail, likelihood, evidence level, and citations.
  • Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.
The big picture

The kinds of drugs Gamma Butyrolactone (gbl) affects

Every type of medication (drug category) Gamma Butyrolactone (gbl) is known to interact with. Open any category for the detail — or search your exact drug in the checker above.

All 10 drug categories Gamma Butyrolactone (gbl) interacts with
Alcohol (ethanol)AmphetaminesAnticonvulsantsCns DepressantsDivalproex Sodium (depakote)Naloxone (narcan)Narcotic DrugsRitonavir (norvir)Saquinavir (fortovase, Invirase)Topiramate (topamax)
Alcohol (Ethanol)

Concomitant use of alcohol may increase the adverse effects of GBL.
GBL is metabolized to gamma-hydroxybutyrate (GHB). In humans, concomitant use of GBL or GHB and alcohol increases the risk of adverse effects, possibly by reducing the elimination of GHB. Concomitant use of GHB and alcohol may also cause additive respiratory and central nervous system depression.

Likelihood Possible Evidence D
Amphetamines

Theoretically, amphetamines may increase or decrease the therapeutic and adverse effects of GBL.
GBL is metabolized to gamma-hydroxybutyrate (GHB). Although some researchers have suggested that amphetamines may antagonize the effects of GHB, this has not been well studied.

Likelihood Possible Evidence D
Anticonvulsants

Theoretically, concomitant use of GBL with certain anticonvulsants may potentiate respiratory and central nervous system (CNS) depression or increase the risk of seizures.
GBL is metabolized to gamma-hydroxybutyrate (GHB). Concomitant use of anticonvulsants that have sedative effects with GHB may cause serious CNS and respiratory depression. GHB can also cause seizures and might reduce the effectiveness of anticonvulsants.

Likelihood Possible Evidence D
Cns Depressants

Theoretically, concomitant use of GBL with CNS depressants may potentiate respiratory and CNS depression.
GBL is metabolized to gamma-hydroxybutyrate (GHB). Concomitant use of CNS depressants with GHB may cause serious CNS and respiratory depression.

Likelihood Possible Evidence D
Divalproex Sodium (Depakote)

Theoretically, concomitant use of GBL with divalproex sodium may potentiate adverse effects.
GBL is metabolized to gamma-hydroxybutyrate (GHB). Concomitant use of divalproex sodium with GHB may increases plasma GHB levels by approximately 25% and may increase the risk of adverse effects.

Likelihood Possible Evidence D
Naloxone (Narcan)

Theoretically, concomitant use of GBL with naloxone may antagonize the effects of GBL.
GBL is metabolized to gamma-hydroxybutyrate (GHB). Theoretically, naloxone may antagonize the effects of GHB; however, anecdotally, naloxone is not effective for treating GHB poisoning.

Likelihood Possible Evidence D
Narcotic Drugs

Theoretically, concomitant use of GBL with narcotic drugs may potentiate respiratory and central nervous system (CNS) depression.
GBL is metabolized to gamma-hydroxybutyrate (GHB). Concomitant use of narcotic drugs with GHB may cause serious CNS and respiratory depression. In one case report, concurrent use of GHB and heroin was fatal.

Likelihood Possible Evidence D
Ritonavir (Norvir)

Concomitant use of GBL with ritonavir may potentiate adverse effects.
GBL is metabolized to gamma-hydroxybutyrate (GHB). Concomitant use of a small dose of GHB with the antiretroviral drugs ritonavir and saquinavir reportedly caused a near-fatal reaction, likely due to inhibition of GHB metabolism.

Likelihood Possible Evidence D
Saquinavir (Fortovase, Invirase)

Concomitant use of GBL with saquinavir may potentiate adverse effects.
GBL is metabolized to gamma-hydroxybutyrate (GHB). Concomitant use of a small dose of GHB with the antiretroviral drugs ritonavir and saquinavir reportedly caused a near-fatal reaction, likely due to inhibition of GHB metabolism.

Likelihood Possible Evidence D
Topiramate (Topamax)

Concomitant use of GBL with topiramate may potentiate adverse effects.
GBL is metabolized to gamma-hydroxybutyrate (GHB). Concomitant use of topiramate with GHB may increase blood levels of GHB. In one case report, a patient regularly taking GHB 4.5 grams twice nightly was hospitalized after initiating treatment with topiramate 25 mg daily. Symptoms included confusion, muscle jerking, miosis, and coma. Plasma levels of GHB were 2.5-fold higher than when GHB was given alone. Potential mechanisms might include decreased GHB breakdown, increased absorption, and/or increased activity.

Likelihood Possible Evidence D
Monograph

Gamma Butyrolactone (gbl): Uses, Safety & Side Effects

Medically reviewed by · Reviewed July 2026 ·
The bottom line

Gamma butyrolactone (GBL) is a toxic industrial solvent, not a dietary supplement, and the body converts it into GHB, a powerful and dangerous sedative. It is illegal to sell or possess for human use in the United States, has no proven medical or supplemental benefit, and can cause coma, seizures, and death. Do not take GBL — if you are seeking help for sleep, anxiety, or substance use, talk to a doctor or pharmacist.

Gamma Butyrolactone (gbl)
Part used
Not applicable (synthetic industrial chemical)
Common forms
Liquid (illicitly sold); used industrially as a solvent
People commonly use it for
  • Recreational intoxication and euphoria
  • Relaxation and sedation
  • Sleep aid (misused)
  • Bodybuilding/muscle building claims (unproven)
  • Industrial solvent and cleaner

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance
OverallBest avoided

GBL is a toxic, illegal substance that can cause coma and death; it should never be consumed.

PregnancyUnsafe

When used orally; avoid using.

Read the full pregnancy detail
BreastfeedingUnsafe

When used orally; avoid using.

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Jump to a section

Overview

Gamma butyrolactone (GBL) is a man-made chemical, not an herb or natural supplement. It is a clear, oily liquid used in industry as a solvent, a paint stripper, and an ingredient in cleaning products, glues, and nail polish remover.

GBL is sometimes sold illegally and swallowed to get high. When a person drinks it, the body quickly turns it into gamma-hydroxybutyrate (GHB), a powerful sedative. GHB is sometimes called a 'club drug' or 'date-rape drug.'

Because of its serious dangers and its link to GHB, GBL is tightly controlled by law in the United States. It has no accepted use as a dietary supplement or medicine, and selling it for people to swallow is illegal.

How it works

After it is swallowed, GBL is rapidly changed by enzymes in the body into GHB. GHB acts on the brain by affecting GABA receptors and other brain signals, which slows down the nervous system.

This slowing effect causes drowsiness, sedation, and loss of consciousness. Because GBL turns into GHB so quickly and the active amount is hard to control, even small differences in how much a person takes can be the difference between sedation and a life-threatening overdose.

Effectiveness

Does Gamma Butyrolactone (gbl) work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by .

Evidence overview · 4 uses evaluated
4 Insufficient evidence
How to read these evidence grades

Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.

1EffectiveStrong, consistent evidence it works.
2Likely EffectiveGood evidence, though not yet conclusive.
3Possibly EffectiveSome evidence suggests a benefit.
4Possibly IneffectiveSome evidence it may not help.
5Likely IneffectiveFairly strong evidence it doesn’t help.
6IneffectiveStrong evidence it doesn’t work.
7Insufficient Reliable Evidence to RateToo little research to say either way.

For Gamma Butyrolactone (gbl), current evidence isn’t strong enough to rate any specific use. The conditions it has been studied for are listed below.

Also studied for 4 conditions — evidence insufficient to rate
Insufficient Reliable Evidence To Rate Athletic performance
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral GBL to improve athletic performance, there is insufficient reliable information about the clinical effects of GBL for this purpose.

Insufficient Reliable Evidence To Rate Depression
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral GBL for depression, there is insufficient reliable information about the clinical effects of GBL for this purpose.

Insufficient Reliable Evidence To Rate Muscle strength
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral GBL for muscle strength, there is insufficient reliable information about the clinical effects of GBL for this purpose.

Insufficient Reliable Evidence To Rate Stress
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral GBL for stress, there is insufficient reliable information about the clinical effects of GBL for this purpose.

Source & disclaimer. Effectiveness ratings and evidence summaries are provided by Natural Medicines (Therapeutic Research Center) and shown as licensed. Where Natural Medicines hasn’t rated a use, HelloPharmacist’s pharmacists may add their own reviewed rating and evidence (each such entry is labeled). This is educational information, not medical advice — talk with your pharmacist or doctor before starting, stopping, or changing a supplement.

Safety & precautions

GBL is very dangerous and illegal to consume. It is caustic and can burn the mouth, throat, and stomach. After it becomes GHB in the body, it can cause deep sedation, coma, slowed or stopped breathing, and death.

The line between a dose that causes a 'high' and one that causes overdose is extremely narrow. Mixing GBL with alcohol or other sedating substances greatly increases the risk of coma and death.

Regular use can lead to physical dependence and addiction. Suddenly stopping after heavy use can cause a severe, sometimes life-threatening withdrawal that needs medical care. Pregnant or breastfeeding people, and everyone else, should never use GBL. If you or someone you know is struggling with GBL or GHB, seek medical help right away.

Side effects

Effects and harms from GBL can include:

  • Dizziness, drowsiness, and confusion
  • Nausea and vomiting
  • Burns to the mouth, throat, and stomach (it is caustic)
  • Slowed heart rate and low blood pressure
  • Slowed or stopped breathing
  • Seizures
  • Unconsciousness, coma, and death

Overdose can happen quickly and is a medical emergency. If someone collapses, will not wake up, or has trouble breathing after using GBL, call emergency services immediately.

Gamma Butyrolactone (gbl): Reported Adverse Effects

Documented safety reports on Gamma Butyrolactone (gbl) from the evidence-graded Natural Medicines (TRC Healthcare) database, shown word-for-word from the licensed record.

GBL is generally considered unsafe for any use. Any benefits do not outweigh the risks of toxicity.

Most Common Adverse Effects:

Orally: Agitation, amnesia, anxiety, bradycardia, confusion, hallucinations, hypotension, nausea, tachycardia, tremor, vomiting.

Serious Adverse Effects (Rare):

Orally: Cardiac arrest, coma, death, pulmonary edema, respiratory depression, seizures, withdrawal.

Reports by condition
Anxiety Psychiatric

Orally, GBL can cause mental changes, such as agitation, combativeness, and amnesia.

Withdrawal symptoms have been reported in people who ingest diluted products containing almost pure GBL every few hours. Withdrawal symptoms can start within 2-72 hours and can last up to 15 days. Withdrawal symptoms have included anxiety, hallucinations, delirium, agitation, and paranoia.

Delirium and agitation have been treated with long-acting benzodiazepines and/or first or second generation antipsychotics. However, treatment with antipsychotics may worsen the severity of these symptoms in some patients. Some patients have also received adjunctive treatment with pregabalin or propranolol.

  1. LoVecchio F, Curry SC, Bagnasco T. Butyrolactone-induced central nervous system depression after ingestion of RenewTrient, a dietary supplement. N Engl J Med 1998;339:847-8.
  2. FDA. FDA warns about products containing gamma butyrolactone or GBL and asks companies to issue a recall. Talk Paper, 21 January 1999.
  3. Anon. Adverse events associated with ingestion of gamma-butyrolactone--Minnesota, New Mexico, and Texas, 1998-1999. MMWR Morb Mortal Wkly Rep 1999;48:137-40.
  4. Bhattacharya IS, Watson F, Bruce M. A case of ?-butyrolactone associated with severe withdrawal delirium and acute renal failure. Eur Addict Res 2011;17(4):169-71.
  5. Eiden C, Capdevielle D, Deddouche C, et al. Neuroleptic malignant syndrome-like reaction precipitated by antipsychotics in a patient with gamma-butyrolactone withdrawal. J Addict Med 2011;5(4):302-3.
  6. Schneir AB, Ly BT, Clark RF. A case of withdrawal from the GHB precursors gamma-butyrolactone and 1,4-butanediol. J Emerg Med 2001;21:31-3..
  7. Sivilotti ML, Burns MJ, Aaron CK, Greenberg MJ. Pentobarbital for severe gamma-butyrolactone withdrawal. Ann Emerg Med 2001;38:660-5..
  8. Zepf FD, Holtmann M, Duketis E, et al. A 16-year-old boy with severe gamma-butyrolactone (GBL) withdrawal delirium. Pharmacopsychiatry 2009;42(5):202-3.
  9. Delic M. Inpatient management of GHB/GBL withdrawal. Psychiatr Danub. 2019 Sep;31(Suppl 3):354-356.
  10. Delcourt N, Lanot T, Vardon-Bounes F, Gandia P, Franchitto N. Severe metabolic failures after recreational ingestion of ?-butyrolactone. J Clin Psychopharmacol. 2020 Nov/Dec;40(6):624-626.
Cardiac arrest Cardiovascular

Orally, GBL can cause bradycardia, hypotension, tachycardia, and cardiac arrest.

Consistent use of GBL followed by abrupt discontinuation is associated with withdrawal symptoms, including tachycardia and hypertension.

  1. LoVecchio F, Curry SC, Bagnasco T. Butyrolactone-induced central nervous system depression after ingestion of RenewTrient, a dietary supplement. N Engl J Med 1998;339:847-8.
  2. FDA. FDA warns about products containing gamma butyrolactone or GBL and asks companies to issue a recall. Talk Paper, 21 January 1999.
  3. Anon. Adverse events associated with ingestion of gamma-butyrolactone--Minnesota, New Mexico, and Texas, 1998-1999. MMWR Morb Mortal Wkly Rep 1999;48:137-40.
  4. Corkery JM, Loi B, Claridge H, et al. Gamma hydroxybutyrate (GHB), gamma butyrolactone (GBL) and 1,4-butanediol (1,4-BD; BDO): A literature review with a focus on UK fatalities related to non-medical use. Neurosci Biobehav Rev 2015;53:52-78.
  5. Dargan PI, Button J, Davies S, et al. The first reported UK fatality related to gamma-butyrolactone (GBL) ingestion. J R Soc Med 2009;102(12):546-7.
  6. Heytens L, Neels H, Van Regenmortel N, et al. Near-fatal persistent anion- and osmolal-gap acidosis due to massive gamma-butyrolactone/ethanol intoxication. Ann Clin Biochem 2015;52(Pt 2):283-7.
  7. Roberts DM, Smith MW, Gopalakrishnan M, et al. Extreme ?-butyrolactone overdose with severe metabolic acidosis requiring hemodialysis. Ann Emerg Med 2011;58(1):83-5.
  8. Delic M. Inpatient management of GHB/GBL withdrawal. Psychiatr Danub. 2019 Sep;31(Suppl 3):354-356.
  9. Schneir AB, Ly BT, Clark RF. A case of withdrawal from the GHB precursors gamma-butyrolactone and 1,4-butanediol. J Emerg Med 2001;21:31-3..
  10. Sivilotti ML, Burns MJ, Aaron CK, Greenberg MJ. Pentobarbital for severe gamma-butyrolactone withdrawal. Ann Emerg Med 2001;38:660-5..
  11. Bhattacharya IS, Watson F, Bruce M. A case of ?-butyrolactone associated with severe withdrawal delirium and acute renal failure. Eur Addict Res 2011;17(4):169-71.
  12. Eiden C, Capdevielle D, Deddouche C, et al. Neuroleptic malignant syndrome-like reaction precipitated by antipsychotics in a patient with gamma-butyrolactone withdrawal. J Addict Med 2011;5(4):302-3.
  13. Zepf FD, Holtmann M, Duketis E, et al. A 16-year-old boy with severe gamma-butyrolactone (GBL) withdrawal delirium. Pharmacopsychiatry 2009;42(5):202-3.
Depression Pulmonary/Respiratory

Orally, GBL can cause slow breathing and respiratory depression resulting in cyanosis, apnea, and hypoxia, possibly requiring intubation. In one case report, a 44-year-old female developed acute lung injury, or chemical pneumonitis, with bilateral alveolar inflammatory consolidations after chronic ingestion of GBL. Infectious sources were ruled out. In another case report, a patient developed pulmonary edema and possible aspiration pneumonia.

  1. LoVecchio F, Curry SC, Bagnasco T. Butyrolactone-induced central nervous system depression after ingestion of RenewTrient, a dietary supplement. N Engl J Med 1998;339:847-8.
  2. FDA. FDA warns about products containing gamma butyrolactone or GBL and asks companies to issue a recall. Talk Paper, 21 January 1999.
  3. Anon. Adverse events associated with ingestion of gamma-butyrolactone--Minnesota, New Mexico, and Texas, 1998-1999. MMWR Morb Mortal Wkly Rep 1999;48:137-40.
  4. FDA Talk Paper. FDA Warns About GBL-Related Products. 1999. Available at: vm.cfsan.fda.gov/~lrd/tpgbl2.html
  5. Bhattacharya IS, Watson F, Bruce M. A case of ?-butyrolactone associated with severe withdrawal delirium and acute renal failure. Eur Addict Res 2011;17(4):169-71.
  6. Corkery JM, Loi B, Claridge H, et al. Gamma hydroxybutyrate (GHB), gamma butyrolactone (GBL) and 1,4-butanediol (1,4-BD; BDO): A literature review with a focus on UK fatalities related to non-medical use. Neurosci Biobehav Rev 2015;53:52-78.
  7. Roberts DM, Smith MW, Gopalakrishnan M, et al. Extreme ?-butyrolactone overdose with severe metabolic acidosis requiring hemodialysis. Ann Emerg Med 2011;58(1):83-5.
  8. van Gerwen M, Scheper H, Touw DJ, van Nieuwkoop C. Life-threatening acute lung injury after gamma butyrolactone ingestion. Neth J Med 2015;73(3):133-5.
  9. van Helmond LPFM, Gresnigt FMJ. Safety of withholding intubation in gamma-hydroxybutyrate- and gamma-butyrolactone-intoxicated coma patients in the emergency department. Eur J Emerg Med. 2020 Jun;27(3):223-227.
Depression Neurologic/CNS

Orally, GBL can cause fainting, seizures, and severe central nervous system depression. In many cases, unconsciousness or coma have been reported.

Withdrawal symptoms have been reported in people who ingest diluted products containing almost pure GBL every few hours. Withdrawal symptoms can start within 2-72 hours and can last for up to 15 days. Withdrawal symptoms have included insomnia, tremor, confusion, rapid eye movement, seizures, profuse sweating, and fever.

  1. LoVecchio F, Curry SC, Bagnasco T. Butyrolactone-induced central nervous system depression after ingestion of RenewTrient, a dietary supplement. N Engl J Med 1998;339:847-8.
  2. FDA. FDA warns about products containing gamma butyrolactone or GBL and asks companies to issue a recall. Talk Paper, 21 January 1999.
  3. Anon. Adverse events associated with ingestion of gamma-butyrolactone--Minnesota, New Mexico, and Texas, 1998-1999. MMWR Morb Mortal Wkly Rep 1999;48:137-40.
  4. Bosch OG, Eisenegger C, Gertsch J, et al. Gamma-hydroxybutyrate enhances mood and prosocial behavior without affecting plasma oxytocin and testosterone. Psychoneuroendocrinology. 2015 Dec;62:1-10.
  5. Corkery JM, Loi B, Claridge H, et al. Gamma hydroxybutyrate (GHB), gamma butyrolactone (GBL) and 1,4-butanediol (1,4-BD; BDO): A literature review with a focus on UK fatalities related to non-medical use. Neurosci Biobehav Rev 2015;53:52-78.
  6. Eiden C, Capdevielle D, Deddouche C, et al. Neuroleptic malignant syndrome-like reaction precipitated by antipsychotics in a patient with gamma-butyrolactone withdrawal. J Addict Med 2011;5(4):302-3.
  7. Heytens L, Neels H, Van Regenmortel N, et al. Near-fatal persistent anion- and osmolal-gap acidosis due to massive gamma-butyrolactone/ethanol intoxication. Ann Clin Biochem 2015;52(Pt 2):283-7.
  8. van Helmond LPFM, Gresnigt FMJ. Safety of withholding intubation in gamma-hydroxybutyrate- and gamma-butyrolactone-intoxicated coma patients in the emergency department. Eur J Emerg Med. 2020 Jun;27(3):223-227.
  9. Delcourt N, Lanot T, Vardon-Bounes F, Gandia P, Franchitto N. Severe metabolic failures after recreational ingestion of ?-butyrolactone. J Clin Psychopharmacol. 2020 Nov/Dec;40(6):624-626.
  10. Bhattacharya IS, Watson F, Bruce M. A case of ?-butyrolactone associated with severe withdrawal delirium and acute renal failure. Eur Addict Res 2011;17(4):169-71.
  11. Delic M. Inpatient management of GHB/GBL withdrawal. Psychiatr Danub. 2019 Sep;31(Suppl 3):354-356.
  12. FDA Talk Paper. FDA Warns About GBL-Related Products. 1999. Available at: vm.cfsan.fda.gov/~lrd/tpgbl2.html
  13. Schneir AB, Ly BT, Clark RF. A case of withdrawal from the GHB precursors gamma-butyrolactone and 1,4-butanediol. J Emerg Med 2001;21:31-3..
  14. Sivilotti ML, Burns MJ, Aaron CK, Greenberg MJ. Pentobarbital for severe gamma-butyrolactone withdrawal. Ann Emerg Med 2001;38:660-5..
Kidney failure Renal

Orally, GBL has been reported to cause acute kidney injury, including changes in serum creatinine levels. There is one case report of a 24-year-old male developing acute kidney failure during withdrawal from GBL obtained from varnish remover. The renal toxicity in this patient was possibly exacerbated by other ingredients in the varnish remover, including propylene glycol.

  1. Bhattacharya IS, Watson F, Bruce M. A case of ?-butyrolactone associated with severe withdrawal delirium and acute renal failure. Eur Addict Res 2011;17(4):169-71.
  2. Roberts DM, Smith MW, Gopalakrishnan M, et al. Extreme ?-butyrolactone overdose with severe metabolic acidosis requiring hemodialysis. Ann Emerg Med 2011;58(1):83-5.
  3. van Helmond LPFM, Gresnigt FMJ. Safety of withholding intubation in gamma-hydroxybutyrate- and gamma-butyrolactone-intoxicated coma patients in the emergency department. Eur J Emerg Med. 2020 Jun;27(3):223-227.
  4. Delcourt N, Lanot T, Vardon-Bounes F, Gandia P, Franchitto N. Severe metabolic failures after recreational ingestion of ?-butyrolactone. J Clin Psychopharmacol. 2020 Nov/Dec;40(6):624-626.
Muscle breakdown Musculoskeletal

Orally, GBL can cause involuntary muscle movements. Rarely, it has been reported to cause rhabdomyolysis.

  1. LoVecchio F, Curry SC, Bagnasco T. Butyrolactone-induced central nervous system depression after ingestion of RenewTrient, a dietary supplement. N Engl J Med 1998;339:847-8.
  2. FDA. FDA warns about products containing gamma butyrolactone or GBL and asks companies to issue a recall. Talk Paper, 21 January 1999.
  3. Anon. Adverse events associated with ingestion of gamma-butyrolactone--Minnesota, New Mexico, and Texas, 1998-1999. MMWR Morb Mortal Wkly Rep 1999;48:137-40.
  4. Bhattacharya IS, Watson F, Bruce M. A case of ?-butyrolactone associated with severe withdrawal delirium and acute renal failure. Eur Addict Res 2011;17(4):169-71.
Nausea and vomiting Gastrointestinal

Orally, GBL can cause bowel incontinence and vomiting.

Consistent use of GBL followed by abrupt discontinuation is associated with withdrawal symptoms, including nausea and vomiting.

  1. LoVecchio F, Curry SC, Bagnasco T. Butyrolactone-induced central nervous system depression after ingestion of RenewTrient, a dietary supplement. N Engl J Med 1998;339:847-8.
  2. FDA. FDA warns about products containing gamma butyrolactone or GBL and asks companies to issue a recall. Talk Paper, 21 January 1999.
  3. Anon. Adverse events associated with ingestion of gamma-butyrolactone--Minnesota, New Mexico, and Texas, 1998-1999. MMWR Morb Mortal Wkly Rep 1999;48:137-40.
  4. Bosch OG, Eisenegger C, Gertsch J, et al. Gamma-hydroxybutyrate enhances mood and prosocial behavior without affecting plasma oxytocin and testosterone. Psychoneuroendocrinology. 2015 Dec;62:1-10.
  5. Heytens L, Neels H, Van Regenmortel N, et al. Near-fatal persistent anion- and osmolal-gap acidosis due to massive gamma-butyrolactone/ethanol intoxication. Ann Clin Biochem 2015;52(Pt 2):283-7.
  6. Bhattacharya IS, Watson F, Bruce M. A case of ?-butyrolactone associated with severe withdrawal delirium and acute renal failure. Eur Addict Res 2011;17(4):169-71.
DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.

Adverse-effects data: Natural Medicines, Therapeutic Research Center

Dosing

There is no safe or recommended dose of GBL. It is not a supplement, it is illegal to sell for human use, and any amount can be dangerous because it converts into the potent sedative GHB.

No pharmacist or doctor should recommend taking GBL. If you are looking for help with sleep, stress, or muscle building, talk with a pharmacist or doctor about safe and legal options.

Pregnancy & Breastfeeding

Gamma Butyrolactone (gbl) & Pregnancy

Unsafe

When used orally; avoid using.

  1. Anon. FDA alert on misuse of consumer products containing GHB, GBL and BD. Food and Drug Administration, Rockville, MD. June 15, 1999.
  2. Anon. Important message for health professionals: Report serious adverse events associated with dietary supplements containing GBL, GHB or BD. Food and Drug Administration, Rockville, MD. August 25, 1999. Available at: http://vm.cfsan.fda.gov/~dms/mwg

Gamma Butyrolactone (gbl) & Breastfeeding

Unsafe

When used orally; avoid using.

  1. Anon. FDA alert on misuse of consumer products containing GHB, GBL and BD. Food and Drug Administration, Rockville, MD. June 15, 1999.
  2. Anon. Important message for health professionals: Report serious adverse events associated with dietary supplements containing GBL, GHB or BD. Food and Drug Administration, Rockville, MD. August 25, 1999. Available at: http://vm.cfsan.fda.gov/~dms/mwg
DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.

© 2026 Therapeutic Research Center

Pregnancy & lactation ratings: Natural Medicines, Therapeutic Research Center

References & further reading

The 28 references that drive our Gamma Butyrolactone (gbl) monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Soderling E, Le Bell A, Kirstila V, Tenovuo J. Betaine-containing toothpaste relieves subjective symptoms of dry mouth. Acta Odontol Scand 1998;56:65-9.
  2. LoVecchio F, Curry SC, Bagnasco T. Butyrolactone-induced central nervous system depression after ingestion of RenewTrient, a dietary supplement. N Engl J Med 1998;339:847-8.
  3. FDA. FDA warns about products containing gamma butyrolactone or GBL and asks companies to issue a recall. Talk Paper, 21 January 1999.
  4. Anon. Adverse events associated with ingestion of gamma-butyrolactone--Minnesota, New Mexico, and Texas, 1998-1999. MMWR Morb Mortal Wkly Rep 1999;48:137-40.
  5. Harrington RD, Woodward JA, Hooton TM, et al. Life-threatening interactions between HIV-1 protease inhibitors and the illicit drugs MDMA and gamma-hydroxybutyrate. Arch Intern Med 1999;159:2221-4.
  6. Anon. FDA alert on misuse of consumer products containing GHB, GBL and BD. Food and Drug Administration, Rockville, MD. June 15, 1999.
  7. Anon. Important message for health professionals: Report serious adverse events associated with dietary supplements containing GBL, GHB or BD. Food and Drug Administration, Rockville, MD. August 25, 1999. Available at: http://vm.cfsan.fda.gov/~dms/mwg
  8. Anon. Multistate outbreak of poisonings associated with illicit use of gamma hydroxy butyrate. JAMA 1991;265:447-8. DOI
  9. Carotenuto A, De Feo V, Fattorusso E, et al. The flavonoids of Allium ursinum. Phytochem 1996;41:531-6. PubMed
  10. FDA Talk Paper. FDA Warns About GBL-Related Products. 1999. Available at: vm.cfsan.fda.gov/~lrd/tpgbl2.html
  11. Ferrara SD, Tedeschi L, Frison G, Rossi A. Fatality due to gamma-hydroxybutyric acid (GHB) and heroin intoxication. J Forensic Sci 1995;40:501-4. DOI
  12. Schneir AB, Ly BT, Clark RF. A case of withdrawal from the GHB precursors gamma-butyrolactone and 1,4-butanediol. J Emerg Med 2001;21:31-3.. PubMed
  13. Sivilotti ML, Burns MJ, Aaron CK, Greenberg MJ. Pentobarbital for severe gamma-butyrolactone withdrawal. Ann Emerg Med 2001;38:660-5.. PubMed
  14. Bosch OG, Eisenegger C, Gertsch J, et al. Gamma-hydroxybutyrate enhances mood and prosocial behavior without affecting plasma oxytocin and testosterone. Psychoneuroendocrinology. 2015 Dec;62:1-10. PubMed
  15. Thai D, Dyer JE, Benowitz NL, Haller CA. Gamma-hydroxybutyrate and ethanol effects and interactions in humans. J Clin Psychopharmacol. 2006 Oct;26(5):524-9. PubMed
Keep reading

This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Pharmacist Counseling Corner

Gamma Butyrolactone (gbl): Common Questions

What is Gamma Butyrolactone (gbl) used for, and does it work?
People use Gamma Butyrolactone (gbl) for a range of reasons, but according to the Natural Medicines database the current clinical evidence is insufficient to confirm it works for the specific conditions it has been studied for. See the graded list on this page, and talk to your pharmacist or doctor before relying on it for any condition.
Does Gamma Butyrolactone (gbl) interact with prescription medications?
Yes. We list 271 medications with a known interaction with Gamma Butyrolactone (gbl). Use the checker above to see how Gamma Butyrolactone (gbl) interacts with a specific drug.
How are Gamma Butyrolactone (gbl) interactions rated?
Each interaction is graded major, moderate, or minor based on how clinically significant it is and the strength of the evidence behind it. Major interactions are the most serious and are best avoided, or used only under close professional supervision.
Is it safe to take Gamma Butyrolactone (gbl) with my medications?
It depends on the specific medication. Some combinations are fine, while others call for monitoring, timing changes, or should be avoided. Check your exact drug above and confirm with your pharmacist or doctor before starting, stopping, or changing anything.
Where does this Gamma Butyrolactone (gbl) interaction information come from?
Our interaction data is built on the Natural Medicines database — an evidence-graded reference for vitamins, herbs, and supplements — and is reviewed by licensed HelloPharmacist pharmacists, who may add clinical context.
Is GBL a dietary supplement?
No. GBL is an industrial solvent, not a supplement or herb. It is illegal to sell for people to swallow and has no proven health benefit.
Why is GBL considered dangerous?
When swallowed, GBL turns into GHB, a powerful sedative. The amount that causes a 'high' is very close to the amount that can cause coma or death, especially when mixed with alcohol.
Is GBL legal?
In the United States, GBL is tightly controlled, and selling or possessing it for human consumption is illegal. It is sold legally only for legitimate industrial purposes.
What should I do if someone takes GBL and won't wake up?
Call emergency services right away. Trouble breathing, deep sedation, or unconsciousness after GBL use is a medical emergency.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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