Nitrous oxide


Nitrous oxide
Accession Number
Small Molecule
Approved, Vet approved

Nitrous oxide, commonly known as "laughing gas", is a chemical compound with the chemical formula N2O. At room temperature, it is a colorless non-flammable gas, with a pleasant, slightly sweet odor and taste. It is used in surgery and dentistry for its anesthetic and analgesic effects. It is known as "laughing gas" due to the euphoric effects of inhaling it, a property that has led to its recreational use as an inhalant drug.

  • Dinitrogen oxide
  • N2O
  • Nitrious oxide
  • Nitrous oxide
  • óxido nitroso
External IDs
E-942 / FEMA NO. 2779 / INS NO.942 / INS-942
Prescription Products
NameDosageStrengthRouteLabellerMarketing StartMarketing End
Nitrous OxideGas990 mL/1LRespiratory (inhalation)DuPuy Oxygen & Supply Company, Inc.1954-01-01Not applicableUs
Nitrous OxideGas99 L/100LRespiratory (inhalation)Air Liquide Canada Inc.1960-01-012016-10-01Us
Nitrous OxideGas992 mL/1LRespiratory (inhalation)Airgas Norpac Inc.1983-01-01Not applicableUs
Nitrous OxideGas990 mL/1LRespiratory (inhalation)MAVERICK OXYGEN & RESPIRATORY EQUIPMENT, LLC2019-12-26Not applicableUs
Nitrous OxideGas990 mL/1LRespiratory (inhalation)ILMO Products Company2012-05-01Not applicableUs
Nitrous OxideGas990 mL/1LRespiratory (inhalation)Praxair Mexico, S. De R.L. De C.V2017-06-08Not applicableUs
Nitrous OxideGas99 kg/100kgRespiratory (inhalation)Holston Gases, Inc1958-01-01Not applicableUs
Nitrous OxideGas990 mL/1LRespiratory (inhalation)Airgas East, Inc.1991-01-15Not applicableUs
Nitrous OxideGas99 L/100LRespiratory (inhalation)Air Liquide Canada Inc.1960-01-012016-10-01Us
Nitrous OxideGas990 mL/1LRespiratory (inhalation)Agl Welding Supply Co., Inc.1966-01-01Not applicableUs
Additional Data Available
  • Application Number
    Application Number

    A unique ID assigned by the FDA when a product is submitted for approval by the labeller.

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  • Product Code
    Product Code

    A governmentally-recognized ID which uniquely identifies the product within its regulatory market.

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Mixture Products
NameIngredientsDosageRouteLabellerMarketing StartMarketing End
Alnox GasNitrous oxide (50 %) + Oxygen (50 %)GasRespiratory (inhalation)Air Liquide Canada Inc.1995-12-31Not applicableCanada
EntonoxNitrous oxide (50 %) + Oxygen (50 %)GasRespiratory (inhalation)Linde Llc1995-12-31Not applicableCanada
Liqui-med Analgesic GasNitrous oxide (50 %) + Oxygen (50 %)GasRespiratory (inhalation)Praxair, Inc.1983-12-31Not applicableCanada
Nitrous Oxide In OxygenNitrous oxide (50 %) + Oxygen (50 %)GasRespiratory (inhalation)Matheson Gas Products Canada Inc.1982-12-311997-12-24Canada
Unapproved/Other Products
NameIngredientsDosageRouteLabellerMarketing StartMarketing End
Nitrous OxideNitrous oxide (99 L/100L)GasRespiratory (inhalation)Linde Gas North America LLC1986-06-16Not applicableUs
Nitrous OxideNitrous oxide (992 mL/1L)GasRespiratory (inhalation)Airgas Norpac Inc.1983-01-01Not applicableUs
Nitrous OxideNitrous oxide (990 mL/1L)GasRespiratory (inhalation)Airgas East, Inc.1991-01-15Not applicableUs
Nitrous OxideNitrous oxide (990 mL/1L)GasRespiratory (inhalation)ILMO Products Company1995-01-01Not applicableUs
Nitrous OxideNitrous oxide (992 mL/1L)GasRespiratory (inhalation)Airgas Intermountain Inc1985-01-01Not applicableUs
Nitrous OxideNitrous oxide (992 mL/1L)GasRespiratory (inhalation)Airgas Mid South, Inc1997-11-062010-08-06Us
Nitrous OxideNitrous oxide (990 mL/1L)GasRectalEncompass Medical & Specialty Gases, Ltd.2008-01-02Not applicableUs
Nitrous OxideNitrous oxide (99 L/100L)GasRespiratory (inhalation)Argyle Welding Supply Company, Inc.1974-01-01Not applicableUs
Nitrous OxideNitrous oxide (99 mL/100mL)GasRespiratory (inhalation)American Welding & Gas2002-01-012010-02-19Us
Nitrous OxideNitrous oxide (99 L/100L)GasRespiratory (inhalation)Strate Welding Supply Co., Inc.1949-01-012018-01-01Us
CAS number
Average: 44.0128
Monoisotopic: 44.001062632
Chemical Formula
InChI Key


Not Available
Associated Therapies
Not Available
Mechanism of action

Findings to date indicate that nitrous oxide induces opioid peptide release in the brain stem leading to the activation of descending noradrenergic neurones, which results in modulation of the nociceptive process in the spinal cord. Several receptor–effector mechanisms including dopamine receptors, α2 adrenoceptors, benzodiazepine receptors and -methyl- -aspartate (NMDA) receptors have been implicated although the relationship of one with the other is not known.

Additional Data Available
Adverse Effects

Comprehensive structured data on known drug adverse effects with statistical prevalence. MedDRA and ICD10 ids are provided for adverse effect conditions and symptoms.

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Additional Data Available

Structured data covering drug contraindications. Each contraindication describes a scenario in which the drug is not to be used. Includes restrictions on co-administration, contraindicated populations, and more.

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Additional Data Available
Blackbox Warnings

Structured data representing warnings from the black box section of drug labels. These warnings cover important and dangerous risks, contraindications, or adverse effects.

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Not Available
Volume of distribution
Not Available
Protein binding
Not Available
Not Available
Route of elimination
Not Available
Half life
Not Available
Not Available
Not Available
Affected organisms
Not Available
Not Available
Pharmacogenomic Effects/ADRs
Not Available


Drug Interactions
This information should not be interpreted without the help of a healthcare provider. If you believe you are experiencing an interaction, contact a healthcare provider immediately. The absence of an interaction does not necessarily mean no interactions exist.
1-benzylimidazoleThe risk or severity of hypertension can be increased when 1-benzylimidazole is combined with Nitrous oxide.
2,5-Dimethoxy-4-ethylamphetamineThe risk or severity of hypertension can be increased when 2,5-Dimethoxy-4-ethylamphetamine is combined with Nitrous oxide.
2,5-Dimethoxy-4-ethylthioamphetamineThe risk or severity of adverse effects can be increased when Nitrous oxide is combined with 2,5-Dimethoxy-4-ethylthioamphetamine.
4-Bromo-2,5-dimethoxyamphetamineThe risk or severity of adverse effects can be increased when 4-Bromo-2,5-dimethoxyamphetamine is combined with Nitrous oxide.
4-MethoxyamphetamineThe risk or severity of adverse effects can be increased when 4-Methoxyamphetamine is combined with Nitrous oxide.
5-methoxy-N,N-dimethyltryptamineThe risk or severity of adverse effects can be increased when Nitrous oxide is combined with 5-methoxy-N,N-dimethyltryptamine.
7-NitroindazoleThe risk or severity of adverse effects can be increased when 7-Nitroindazole is combined with Nitrous oxide.
7,8-Dichloro-1,2,3,4-tetrahydroisoquinolineThe risk or severity of adverse effects can be increased when Nitrous oxide is combined with 7,8-Dichloro-1,2,3,4-tetrahydroisoquinoline.
AbediterolThe risk or severity of hypertension can be increased when Nitrous oxide is combined with Abediterol.
AcebutololNitrous oxide may decrease the antihypertensive activities of Acebutolol.
Additional Data Available
  • Extended Description
    Extended Description

    Extended description of the mechanism of action and particular properties of each drug interaction.

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  • Severity

    A severity rating for each drug interaction, from minor to major.

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  • Evidence Level
    Evidence Level

    A rating for the strength of the evidence supporting each drug interaction.

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  • Action

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Food Interactions
Not Available


General References
Not Available
External Links
Human Metabolome Database
KEGG Compound
PubChem Compound
PubChem Substance
PDBe Ligand
ATC Codes
N01AX13 — Nitrous oxideN01AX63 — Nitrous oxide, combinations
AHFS Codes
  • 28:04.16 — Inhalation Anesthetics
PDB Entries
2icq / 2ie7 / 2ppa / 3pk3 / 3pks / 3pkt / 3pku / 3ple / 3plg / 3plh
show 7 more

Clinical Trials

Clinical Trials
0CompletedTreatmentAnxiety Disease1
0RecruitingTreatmentNitrous Oxide1
0RecruitingTreatmentMinor burns / Pain, Acute1
0TerminatedTreatmentBipolar Depressive Disorder / Bipolar Disorder (BD) / Treatment- Resistant Bipolar Disorder1
0Unknown StatusTreatmentPain, Neuropathic1
1Active Not RecruitingBasic ScienceHealthy Volunteers1
1Active Not RecruitingTreatmentDepressive Disorder, Treatment-Resistant / Major Depressive Disorder (MDD)1
1Enrolling by InvitationTreatmentDepression / Major Depressive Disorder (MDD) / Moods Disorders / Suicidal Thoughts1
1TerminatedTreatmentVasodilation (usually flushing)1
1, 2CompletedHealth Services ResearchAnaesthesia therapy1
2Active Not RecruitingTreatmentDepressive Disorder, Treatment-Resistant / Major Depressive Disorder (MDD)1
2CompletedNot AvailableAlcohol-Related Disorders / Opioid-Related Disorders / Substance-Related Disorders1
2CompletedTreatmentDepression / Major Depressive Disorder (MDD)1
2CompletedTreatmentOpioid-Related Disorders / Substance-Related Disorders6
2Not Yet RecruitingTreatmentObsessive Compulsive Disorder (OCD)1
2RecruitingTreatmentBipolar Disorder (BD)1
2RecruitingTreatmentDepression / Depressive Disorders / Major Depressive Disorder (MDD) / Treatment Resistant Depression (TRD)1
2RecruitingTreatmentDepression / Major Depressive Disorder (MDD)1
2RecruitingTreatmentPost Traumatic Stress Disorder (PTSD)1
2RecruitingTreatmentSickle Cell Disorders / Vaso-occlusive Crisis1
2TerminatedTreatmentPain, Labor1
2, 3CompletedTreatmentAnaesthesia therapy1
2, 3Not Yet RecruitingSupportive CareAdolescent Health / Analgesia / Contraceptive Devices / Gynecology / Long-Acting Reversible Contraception1
2, 3RecruitingTreatmentObstetrical analgesia therapy / Obstetrical Anesthesia / Postpartum Depression1
2, 3TerminatedTreatmentPain, Acute1
3CompletedPreventionColorectal Cancers1
3CompletedTreatmentBehavior, Child1
3CompletedTreatmentBreech Presentation in Pregnancy1
3CompletedTreatmentComplications, Pregnancy / Complications; Cesarean Section / Fetus or Neonate Affected by External Version Before Labor / Inhalation of Nitrous Oxide / Non-cephalic Presentation1
3CompletedTreatmentExternal Cephalic Version1
3CompletedTreatmentInjection Site Vesicles1
3Enrolling by InvitationTreatmentComplex Regional Pain Syndrome (CRPS)1
3Unknown StatusTreatmentFiberoptic Bronchoscopy1
3WithdrawnNot AvailableAnalgesic Affect1
3WithdrawnTreatmentMinor burns1
4CompletedNot AvailableAnaesthesia therapy1
4CompletedBasic ScienceAdjunct to general anesthesia therapy / Adverse Effects / Nitrous Oxide1
4CompletedBasic ScienceHealthy Volunteers1
4CompletedDiagnosticDepth of Anaesthesia1
4CompletedDiagnosticGlaucoma / Sedation1
4CompletedDiagnosticMalignancies / Pain1
4CompletedOtherLumbar Punctures / Minor Incision Drainage of Abscesses Not Requiring Extensive Debridement / Sedation, Conscious / Simple Lacerations Less Than 4 cm1
4CompletedPreventionEffects of Nitrous Oxide Following Anaesthesia / Induced Endothelial Dysfunction / Quality of Recovery From Anaesthesia1
4CompletedSupportive CareLeukemias / Non-Hodgkin's Lymphoma (NHL)1
4CompletedTreatmentAcute Coronary Syndromes (ACS)1
4CompletedTreatmentAdhesive Capsulitis1
4CompletedTreatmentAnaesthesia therapy2
4CompletedTreatmentAnalgesia / Bowel Cancer Screening / Colonoscopy / Entonox1
4CompletedTreatmentAnxiety / Pain1
4CompletedTreatmentHeadache / Hydrocephaly / Neoplasms, Abdominal / Neurofibromatoses / Seizures Disorders / Spine Deformity / Tumors1
4CompletedTreatmentLung Function1
4CompletedTreatmentAdjunct to general anesthesia therapy / Middle Aged Patients1
4CompletedTreatmentPain, Acute1
4CompletedTreatmentPulmonary Function Under Anaesthesia1
4Not Yet RecruitingTreatmentSafety and Efficacy of Intranasal Dexmedetomidine1
4RecruitingTreatmentAnxiety / Pain1
4RecruitingTreatmentDental Anxiety / Pain1
4RecruitingTreatmentLumbar Puncture1
4RecruitingTreatmentPain / Stress Incontinence, Female1
4RecruitingTreatmentPatients Requiring Diagnostic Gastroscopy Suitable for Sedation / Patients Requiring Diagnostic Gastroscopy With Sedation1
4RecruitingTreatmentWounds, Nonpenetrating1
4SuspendedTreatmentAnaesthesia therapy / Delirium, Dementia, Amnestic, Cognitive Disorders1
4WithdrawnTreatmentAbscesses / Laceration1
Not AvailableActive Not RecruitingSupportive CareAbdominal Hysterectomy (& Wertheim) / Adjunct to general anesthesia therapy / Nitrous Oxide1
Not AvailableCompletedNot AvailableAlcohol-Related Disorders / Opioid-Related Disorders / Substance-Related Disorders1
Not AvailableCompletedNot AvailableAmnesia1
Not AvailableCompletedNot AvailableClinical Anxiety / Clinical Cooperation1
Not AvailableCompletedNot AvailableOpioid-Related Disorders / Substance-Related Disorders6
Not AvailableCompletedBasic ScienceNitrous Oxide Poisoning1
Not AvailableCompletedHealth Services ResearchAdjunct to general anesthesia therapy / Deep Sedation1
Not AvailableCompletedOtherAdverse Effect of Unspecified General Anesthetic / Exposure to Environmental Pollution1
Not AvailableCompletedOtherPregnancy Termination in Second Trimester1
Not AvailableCompletedPreventionBreast Cancer1
Not AvailableCompletedPreventionCardiovascular Abnormalities1
Not AvailableCompletedTreatmentAbscesses / Laceration1
Not AvailableCompletedTreatmentEmergence Reaction / Procedural Sedation1
Not AvailableCompletedTreatmentMigraine / Pain1
Not AvailableCompletedTreatmentOpioid-Related Disorders / Substance-Related Disorders1
Not AvailableNot Yet RecruitingBasic ScienceNitrous Oxyde / Treatment Resistant Depression (TRD)1
Not AvailableNot Yet RecruitingTreatmentAnxiety1
Not AvailableNot Yet RecruitingTreatmentColonic Neoplasms1
Not AvailableNot Yet RecruitingTreatmentDehydrated Infants Needing Nasogastric Tube Placement for Rehydration / Mild to Moderate Dehydration1
Not AvailableRecruitingOtherAnxiety / Pain / Venous Puncture1
Not AvailableRecruitingSupportive CareInguinal Herniorrhaphy / Post Operative Pain1
Not AvailableRecruitingTreatmentAbscesses1
Not AvailableRecruitingTreatmentAbscesses / Joint dislocations / Perianal Abscess1
Not AvailableRecruitingTreatmentAdjunct to general anesthesia therapy / Anesthesia Recovery Period / Elective Surgical Procedures / Laparoscopy / Laparotomy1
Not AvailableRecruitingTreatmentDuration of Labor / Entonox / Nulliparous1
Not AvailableRecruitingTreatmentPain, Labor1
Not AvailableUnknown StatusTreatmentPain, Labor1
Not AvailableWithdrawnPreventionRespiratory Complications / Swallowing Disorders1
Not AvailableWithdrawnTreatmentLocal Anesthetic Efficacy1


Not Available
Not Available
Dosage forms
GasRectal990 mL/1L
GasRespiratory (inhalation)900 mL/1L
GasRespiratory (inhalation)98 %
GasRespiratory (inhalation)99 mL/100mL
GasRespiratory (inhalation)99 L/100L
GasRespiratory (inhalation)99 kg/100kg
GasRespiratory (inhalation)99 mL/1L
GasRespiratory (inhalation)99.5 L/1L
GasRespiratory (inhalation)99.5 L/100L
GasRespiratory (inhalation)990 mL/1L
GasRespiratory (inhalation)992 mL/1L
GasRespiratory (inhalation)995 mL/1L
LiquidRespiratory (inhalation)99 L/100L
GasRespiratory (inhalation)
GasRespiratory (inhalation)
Not Available
Not Available


Experimental Properties
melting point (°C)-90.81 °CPhysProp
boiling point (°C)-88.46 °CPhysProp
logP0.36HANSCH,C ET AL. (1995)
Predicted Properties
pKa (Strongest Acidic)4.65ChemAxon
pKa (Strongest Basic)-7.3ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count2ChemAxon
Hydrogen Donor Count0ChemAxon
Polar Surface Area51.21 Å2ChemAxon
Rotatable Bond Count0ChemAxon
Refractivity27.67 m3·mol-1ChemAxon
Polarizability2.55 Å3ChemAxon
Number of Rings0ChemAxon
Rule of FiveYesChemAxon
Ghose FilterNoChemAxon
Veber's RuleNoChemAxon
MDDR-like RuleNoChemAxon
Predicted ADMET features
Human Intestinal Absorption+0.9467
Blood Brain Barrier+0.9872
Caco-2 permeable+0.5561
P-glycoprotein substrateNon-substrate0.9009
P-glycoprotein inhibitor INon-inhibitor0.9747
P-glycoprotein inhibitor IINon-inhibitor0.9944
Renal organic cation transporterNon-inhibitor0.9407
CYP450 2C9 substrateNon-substrate0.8867
CYP450 2D6 substrateNon-substrate0.8789
CYP450 3A4 substrateNon-substrate0.7447
CYP450 1A2 substrateNon-inhibitor0.7496
CYP450 2C9 inhibitorNon-inhibitor0.9074
CYP450 2D6 inhibitorNon-inhibitor0.9293
CYP450 2C19 inhibitorNon-inhibitor0.9089
CYP450 3A4 inhibitorNon-inhibitor0.9871
CYP450 inhibitory promiscuityLow CYP Inhibitory Promiscuity0.9435
Ames testAMES toxic0.7381
CarcinogenicityCarcinogens 0.6906
BiodegradationReady biodegradable0.9704
Rat acute toxicity2.8320 LD50, mol/kg Not applicable
hERG inhibition (predictor I)Weak inhibitor0.8497
hERG inhibition (predictor II)Non-inhibitor0.971
ADMET data is predicted using admetSAR, a free tool for evaluating chemical ADMET properties. (23092397)


Mass Spec (NIST)
Not Available
SpectrumSpectrum TypeSplash Key
Predicted GC-MS Spectrum - GC-MSPredicted GC-MSNot Available
Predicted MS/MS Spectrum - 10V, Positive (Annotated)Predicted LC-MS/MSsplash10-0002-9000000000-2eee7435817186856ef7
Predicted MS/MS Spectrum - 20V, Positive (Annotated)Predicted LC-MS/MSsplash10-001j-9000000000-d1a5381e3dd214cad7ab
Predicted MS/MS Spectrum - 40V, Positive (Annotated)Predicted LC-MS/MSsplash10-000t-9000000000-3ae2e01e3d626729760b
Predicted MS/MS Spectrum - 10V, Negative (Annotated)Predicted LC-MS/MSsplash10-004l-9000000000-c53ff0d270e0310b3375
Predicted MS/MS Spectrum - 20V, Negative (Annotated)Predicted LC-MS/MSsplash10-004i-9000000000-c8b9d8f80d3f41ad7f54
Predicted MS/MS Spectrum - 40V, Negative (Annotated)Predicted LC-MS/MSsplash10-002f-9000000000-12c3fe456373daff732e


This compound belongs to the class of inorganic compounds known as other non-metal nitrides. These are inorganic compounds of nitrogen where nitrogen has a formal oxidation state of -3, and the heaviest atom bonded to it belongs to the class of 'other non-metals'.
Inorganic compounds
Super Class
Homogeneous non-metal compounds
Other non-metal organides
Sub Class
Other non-metal nitrides
Direct Parent
Other non-metal nitrides
Alternative Parents
Inorganic oxides / Inorganic nitrides
Other non-metal nitride / Inorganic nitride / Inorganic oxide
Molecular Framework
Not Available
External Descriptors
nitrogen oxide (CHEBI:17045) / a non-metabolic compound (NITROUS-OXIDE)

Drug created on September 02, 2008 09:56 / Updated on March 30, 2020 22:56

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