Morphine

M, Miss Emma, Morpho, Dreamer, White Stuff

Psychoactive Class

Chemical Class

Morphine is the principal alkaloid of the opium poppy (Papaver somniferum)¹ and the prototypical opioid analgesic.² First isolated by Friedrich Sertürner in 1805,³ it has served as the foundation from which numerous semi-synthetic opioids have been derived. Morphine produces potent analgesia,⁴ euphoria,⁴ and sedation,⁴ and is used clinically for the management of moderate to severe pain.⁴ Its use carries significant risks of tolerance, physical dependence,⁵ and abuse.⁵

Dosage & Duration

Dosage

Moderate15-25 mg

Strong30+ mg

Bioavailability

40-50%

Duration

Onset10-30 minutes

Total4-6 hours

Half-life

2-3 hours

Subjective Effects

Effects vary widely by individual, dose, and context.

Physical

Pain relief Respiratory depression Itchiness Constipation Cough suppression Difficulty urinating Nausea Sedation Pupil constriction Decreased libido

Cognitive

Anxiety suppression Compulsive redosing

Visual

Forked from Subjective Effect Documentation work

by Josie KinsAugust 2016.

Reagent Testing

Loading reagent data

Expected colorimetric results are being prepared.

Pharmacology

Pharmacodynamics

Morphine acts primarily as an agonist at the μ-opioid receptor (MOR), which mediates its principal pharmacological effects.⁶ Its intrinsic activity at the MOR is context-dependent; it functions as a full agonist under some assay and tissue conditions while behaving as a partial agonist or antagonist in others.⁶ Morphine also activates κ-opioid and δ-opioid receptors, and interacts predominantly with the μ–δ-opioid receptor heteromer.⁷⁸ Peripherally, it acts on μ-opioid receptors expressed in the myenteric plexus of the gastrointestinal tract, reducing gut motility.⁴

Pharmacokinetics

Morphine undergoes extensive first-pass metabolism in the liver, resulting in an oral bioavailability of approximately 40 to 50%.⁴ It is approximately 35% protein bound with a volume of distribution of 5.31 L/kg.⁹ Metabolism occurs primarily via glucuronidation by UGT2B7 at the 3 and 6 positions, predominantly in the liver with minor contributions from the brain and kidneys.¹⁰ The major metabolite, morphine-3-glucuronide (approximately 60% of a dose), is pharmacologically inactive, while morphine-6-glucuronide (6 to 10% of a dose) is an active metabolite that retains μ-opioid receptor affinity¹¹¹² and is estimated to account for approximately 85% of the observed pharmacological response.¹³ The elimination half-life is approximately 2 to 3 hours, and roughly 87% of a dose is excreted renally within 72 hours, with 2 to 10% recovered as unchanged morphine.⁴

Interactions

Dangerous

Highest risk

These combinations are considered extremely harmful and should always be avoided. Reactions to these drugs taken in combination are highly unpredictable and have a potential to cause death.

AlcoholBenzodiazepinesCocaineDXMGHB/GBLKetamineMXEPregabalinTramadol

Unsafe

Avoid

There is considerable risk of physical harm when taking these combinations, they should be avoided where possible.

Diphenhydramine

Caution

Use caution

These combinations are not usually physically harmful, but may produce undesirable effects, such as physical discomfort or overstimulation. Extreme use may cause physical health issues. Synergistic effects may be unpredictable. Care should be taken when choosing to use this combination.

AmphetaminesMAOIsMephedroneNitrous oxidePCP

TripSit

Tolerance

Full Tolerance

Tolerance develops rapidly with repeated use, sometimes after only a short period of consumption. This necessitates progressively higher doses to achieve the same effects.

Cross Tolerance

Opioids (μ-opioid receptor agonists)

Baseline Reset

After a period of abstinence, tolerance decreases significantly. Users returning to the substance after abstinence should use substantially lower doses than their pre-abstinence amounts, as their previous typical dose may produce life-threatening effects.

Harm Potential

Addiction & Dependence

Psychological

Extremely High

Morphine is ranked among the most addictive substances known, with studies placing it alongside heroin as the most addictive drug. Psychological dependence is complex and protracted, persisting long after physical withdrawal resolves.¹⁴ Relapse rates are estimated as high as 98%, and users commonly experience severe depression, anxiety, and overwhelming drug craving during recovery.

Physical

Extremely High

Physical dependence develops readily with repeated administration, sometimes after only a short period of use. Withdrawal produces the prototypical opioid withdrawal syndrome with symptoms including anxiety, perspiration, muscle aches, severe cramping, diarrhea, vomiting, and intense drug craving progressing through distinct stages over 7-12 days.¹⁵ While withdrawal is not typically fatal in otherwise healthy individuals, it is intensely uncomfortable.

Toxicity

Gastrointestinal

Constipation is one of the most common side effects, occurring consistently even at typical therapeutic doses due to reduced gut motility.¹⁶

Endocrine

Chronic use causes hypogonadism and hormone imbalances in the majority of long-term users of both sexes; studies suggest up to 90% of chronic opioid users experience opioid-induced hypogonadism.

Immune System

Chronic use may suppress immune function and increase susceptibility to infections including pneumonia, tuberculosis, and HIV/AIDS; this immunosuppressive effect is primarily documented in individuals with opioid addiction.¹⁹

Central Nervous System

Excess consumption over time can cause changes in synaptic neuroplasticity; these effects are associated with chronic heavy use rather than occasional administration.²⁰

Psychosis Risk

Confusion, nightmares, and hallucinations may occur as side effects, though these are not prominently reported at typical doses.

History & Culture

Ancient and Early Use

The history of morphine is deeply intertwined with humanity's long relationship with the opium poppy. The earliest documented references to opium-based preparations can be traced to the 3rd century BC, when the Greek philosopher Theophrastus recorded their existence.²¹ Some…

Legality

By Country

United StatesPrescription onlySchedule II

Controlled Substances Act; 21 CFR § 1308.12⁶³⁶⁴

Morphine is a Schedule II controlled substance under federal law. A Schedule II morphine prescription drug generally may be dispensed only on a practitioner's written prescription, subject to the statutory emergency exception, and may not be refilled.

AustriaIllegalAnhang I

Suchtgiftverordnung, Anhang I³⁵³⁶

Morphine is listed as a Suchtgift in I.1.b of Annex I to Austria’s Suchtgiftverordnung. Unauthorized acquisition, possession, production, transport, import, export, offering, supply, or procurement of a Suchtgift is punishable under § 27(1) of the Suchtmittelgesetz by up to one year’s imprisonment or a fine of up to 360 daily rates.

BrazilIllegalLista A1

Portaria SVS/MS nº 344, de 12 de maio de 1998, Anexo I³⁹⁴⁰

Morphine is listed in Lista A1, Brazil’s list of narcotic substances, in Annex I to Portaria SVS/MS No. 344 of 12 May 1998. The listing places morphine under the special-control regime: its manufacture, import, export, prescription, dispensing, and other handling require compliance with the regulation’s authorization and recordkeeping rules.

FinlandIllegalLiite I

Government Decree on Substances Regarded as Narcotics (543/2008), Annex I⁴³⁴⁴

Morphine is listed in Liite I of the Government Decree on Substances Regarded as Narcotics (543/2008). Under Finland's Narcotics Act, the production, manufacture, import, export, transit, distribution, trade, handling, possession, and use of narcotics are prohibited unless the Act provides otherwise.

IndonesiaIllegalGolongan II

Law No. 35 of 2009 on Narcotics, Annex I⁴⁷⁴⁸

Morphine (Morfina) is listed in the Group II narcotics list in Annex I to Indonesia’s Law No. 35 of 2009 on Narcotics, in force since 12 October 2009. It can be supplied for medical care under the statutory system, including a patient's lawful possession, while unauthorized possession, production, distribution, import, or export is a criminal offence.

NetherlandsIllegalLijst I

Opiumwet, Lijst I⁵⁰

Morphine (morfine) is listed in Lijst I of the Netherlands' Opiumwet. Article 2 prohibits importing or exporting, preparing, processing, selling, supplying, transporting, possessing, and manufacturing Lijst I substances; the Act provides regulated exceptions for authorized medical activities and exemptions.

SingaporeIllegalClass A drugs

Misuse of Drugs Act 1973, First Schedule⁵²⁵³

Morphine is a Class A controlled drug listed in the First Schedule to Singapore’s Misuse of Drugs Act 1973. Unless authorised by the Act, possession, consumption, trafficking, and acts preparatory to trafficking are offences.

ThailandIllegalประเภท 2

ประกาศกระทรวงสาธารณสุข เรื่อง ระบุชื่อยาเสพติดให้โทษในประเภท 2 พ.ศ. 2565⁵⁶⁵⁷⁵⁸

Morphine is listed as a Category 2 narcotic under the Ministry of Public Health notification specifying Category 2 narcotics. Thailand restricts the production, import, and export of Category 2 narcotics, and requires authorization to sell or possess them.

AustraliaLegal (regulated)Schedule 8

Therapeutic Goods (Poisons Standard—June 2026) Instrument 2026³⁴

The federal Poisons Standard lists morphine in Schedule 8. Schedule 8 controlled drugs remain available for use but carry restrictions on manufacture, supply, distribution, possession and use. The Standard sets the scheduling classification, which state and territory legislation implements.

BelgiumIllegalAnnexe Ia

Royal Decree of 6 September 2017 regulating narcotic and psychotropic substances³⁷³⁸

Morphine is listed in Annexe Ia of Belgium’s Royal Decree of 6 September 2017 regulating narcotic and psychotropic substances. Import, export, transport, manufacture, production, possession, sale, supply, dispensing, and acquisition of listed products require prior authorization; lawfully obtained medicines are excepted from the authorization requirement for acquisition and possession.

ColombiaLegal (regulated)Lista Amarilla I

Resolución 315 de 2020⁴¹⁴²

Morphine is listed as a Schedule I narcotic (Lista Amarilla, Lista I) in Colombia's national controlled-substances annex. It is also classified as a State-monopoly substance, and listed morphine hydrochloride products are medicines of special control under that monopoly. Dispensing of State-monopoly medicines requires a medical prescription under the continuing distribution rules of Resolución 1478 de 2006.

IndiaIllegalOpium derivative

Narcotic Drugs and Psychotropic Substances Act, 1985⁴⁵⁴⁶

Morphine is an opium derivative under the Narcotic Drugs and Psychotropic Substances Act, 1985, and is consequently a manufactured drug and narcotic drug under that Act. Section 8 prohibits the production, manufacture, possession, sale, purchase, transport, warehousing, use, consumption, and specified import or export dealings in narcotic drugs except for medical or scientific purposes and as authorized by the Act, rules, or orders. The Act has been in force since 14 November 1985.

MexicoPrescription onlyEstupefaciente

Ley General de Salud, arts. 234 and 240⁴⁹

Mexico lists morphine, its salts, and its preparations as estupefacients under the General Health Law. The law permits only specified licensed health professionals to prescribe estupefacients, subject to the law, its regulations, and Health Ministry requirements.

New ZealandIllegalClass B controlled drugs

Misuse of Drugs Act 1975, Schedule 1 Part 2⁵¹

Morphine is listed in Part 2 of Schedule 1 to the Misuse of Drugs Act 1975 as a Class B controlled drug. The Act makes unauthorised possession and dealings, including importation, exportation, manufacture, supply, and sale, offences except as authorised under its statutory framework.

SwedenIllegalFörteckning II

Läkemedelsverkets föreskrifter (LVFS 2011:10) om förteckningar över narkotika⁵⁴⁵⁵

Morphine is listed as morfin in Förteckning II of the Swedish Medical Products Agency's narcotics schedules. Unauthorised transfer, manufacture, acquisition, possession, use, and other dealings in narcotics are criminal offences under the Narcotics Criminal Act; authorised medical handling is regulated separately.

United KingdomPrescription onlyClass A; Schedule 2

Misuse of Drugs Act 1971; Misuse of Drugs Regulations 2001^59606162

Morphine is a Class A controlled drug under the Misuse of Drugs Act 1971 and a Schedule 2 controlled drug under the Misuse of Drugs Regulations 2001. Unauthorised possession is an offence, while medical supply is subject to the Regulations’ prescription and professional controls.

References

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Morphine

M, Miss Emma, Morpho, Dreamer, White Stuff

Psychoactive Class

Opioid Depressant

Chemical Class

Morphinan Alkaloid (opium)

Dosage & Duration

Dosage

Moderate15-25 mg

Strong30+ mg

Bioavailability

40-50%

Duration

Onset10-30 minutes

Total4-6 hours

Half-life

2-3 hours

Subjective Effects

Effects vary widely by individual, dose, and context.

Physical

Pain relief Respiratory depression Itchiness Constipation Cough suppression Difficulty urinating Nausea Sedation Pupil constriction Decreased libido

Cognitive

Anxiety suppression Compulsive redosing

Visual

Forked from Subjective Effect Documentation work

by Josie KinsAugust 2016.

Reagent Testing

Loading reagent data

Expected colorimetric results are being prepared.

Pharmacology

Pharmacodynamics

Pharmacokinetics

Interactions

Dangerous

Highest risk

These combinations are considered extremely harmful and should always be avoided. Reactions to these drugs taken in combination are highly unpredictable and have a potential to cause death.

AlcoholBenzodiazepinesCocaineDXMGHB/GBLKetamineMXEPregabalinTramadol

Unsafe

Avoid

There is considerable risk of physical harm when taking these combinations, they should be avoided where possible.

Diphenhydramine

Caution

Use caution

AmphetaminesMAOIsMephedroneNitrous oxidePCP

TripSit

Tolerance

Full Tolerance

Tolerance develops rapidly with repeated use, sometimes after only a short period of consumption. This necessitates progressively higher doses to achieve the same effects.

Cross Tolerance

Opioids (μ-opioid receptor agonists)

Baseline Reset

Harm Potential

Addiction & Dependence

Psychological

Extremely High

Physical

Extremely High

Toxicity

Gastrointestinal

Constipation is one of the most common side effects, occurring consistently even at typical therapeutic doses due to reduced gut motility.¹⁶

Endocrine

Chronic use causes hypogonadism and hormone imbalances in the majority of long-term users of both sexes; studies suggest up to 90% of chronic opioid users experience opioid-induced hypogonadism.

Immune System

Central Nervous System

Excess consumption over time can cause changes in synaptic neuroplasticity; these effects are associated with chronic heavy use rather than occasional administration.²⁰

Psychosis Risk

Confusion, nightmares, and hallucinations may occur as side effects, though these are not prominently reported at typical doses.

History & Culture

Ancient and Early Use

Legality

By Country

United StatesPrescription onlySchedule II

Controlled Substances Act; 21 CFR § 1308.12⁶³⁶⁴

AustriaIllegalAnhang I

Suchtgiftverordnung, Anhang I³⁵³⁶

BrazilIllegalLista A1

Portaria SVS/MS nº 344, de 12 de maio de 1998, Anexo I³⁹⁴⁰

FinlandIllegalLiite I

Government Decree on Substances Regarded as Narcotics (543/2008), Annex I⁴³⁴⁴

IndonesiaIllegalGolongan II

Law No. 35 of 2009 on Narcotics, Annex I⁴⁷⁴⁸

NetherlandsIllegalLijst I

Opiumwet, Lijst I⁵⁰

SingaporeIllegalClass A drugs

Misuse of Drugs Act 1973, First Schedule⁵²⁵³

ThailandIllegalประเภท 2

AustraliaLegal (regulated)Schedule 8

Therapeutic Goods (Poisons Standard—June 2026) Instrument 2026³⁴

BelgiumIllegalAnnexe Ia

Royal Decree of 6 September 2017 regulating narcotic and psychotropic substances³⁷³⁸

ColombiaLegal (regulated)Lista Amarilla I

Resolución 315 de 2020⁴¹⁴²

IndiaIllegalOpium derivative

Narcotic Drugs and Psychotropic Substances Act, 1985⁴⁵⁴⁶

MexicoPrescription onlyEstupefaciente

Ley General de Salud, arts. 234 and 240⁴⁹

New ZealandIllegalClass B controlled drugs

Misuse of Drugs Act 1975, Schedule 1 Part 2⁵¹

SwedenIllegalFörteckning II

Läkemedelsverkets föreskrifter (LVFS 2011:10) om förteckningar över narkotika⁵⁴⁵⁵

United KingdomPrescription onlyClass A; Schedule 2

Misuse of Drugs Act 1971; Misuse of Drugs Regulations 2001^59606162

References

Source Pages

Citations

Suggest an edit

Spotted a mistake, an outdated claim, or something missing from the Morphine article? Send the editors a private note. Feedback lands in a moderation queue and is never shown on the site.

Morphine

Contents

Dosage & Duration

Dosage

Duration

Subjective Effects

Physical

Cognitive

Visual

Reagent Testing

Pharmacology

Pharmacodynamics

Pharmacokinetics

Interactions

Dangerous

Unsafe

Caution

Tolerance

Harm Potential

Addiction & Dependence

Psychological

Physical

Toxicity

Psychosis Risk

History & Culture

Ancient and Early Use

Legality

By Country

References

Source Pages

Citations

Further Reading

Suggest an edit

Morphine

Contents

Dosage & Duration

Dosage

Duration

Subjective Effects

Physical

Cognitive

Visual

Reagent Testing

Pharmacology

Pharmacodynamics

Pharmacokinetics

Interactions

Dangerous

Unsafe

Caution

Tolerance

Harm Potential

Addiction & Dependence

Psychological

Physical

Toxicity

Psychosis Risk

History & Culture

Ancient and Early Use

Legality

By Country

References

Source Pages

Citations

Further Reading

Suggest an edit