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Desomorphine

Overview

Desomorphine (dihydrodesoxymorphine) — krokodil — is a semi-synthetic opioid of the morphinan class. It is a structural derivative of morphine, approximately 8–10 times more potent as a painkiller. It activates opioid receptors in the brain and spinal cord, suppressing pain signaling and producing its characteristic sedation.

Desomorphine (dihydrodesoxymorphine) — krokodil — is a semi-synthetic opioid of the morphinan class. It is a structural derivative of morphine, approximately 8–10 times more potent as an analgesic.[1] Desomorphine is a full agonist at µ-opioid receptors, producing its effects by suppressing pain signaling and depressing respiratory and autonomic function.[2]

Entity
Desomorphine
PSX-0152
Desomorphine 2D chemical structure
Open Beta

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NoticeAll →
•Dangerous withdrawal, taper carefully
•High overdose risk, use caution
•Compulsive use risk, monitor frequency
•High dependence, taper carefully
•Chronic toxicity, limit exposure
•4 lethal interactions(all →)
Common namesDesomorphine, Krokodil, Krok
Substitutive name4,5-epoxy-3-hydroxy-N-methylmorphinan
Threshold
< 10 mg
Light
10 – 15 mg
Common
15 – 20 mg
Strong
20 – 30 mg
Heavy
30+ mg
Builduprapid
Full reset14 days
Cross-tol.opioids
Absolute4 entries
Respiratory insufficiency (COPD, severe asthma, sleep apnea)Known hypersensitivity to morphinan opioidsConcurrent CNS depressants (benzodiazepines, alcohol, barbiturates, other opioids)MAOI co-administration (within 14 days)
Relative2 entries
Head injury or raised intracranial pressureParalytic ileus or bowel obstruction
Dosage varies by body weight, tolerance & metabolism · Not medical advice · Terms
See an error? Suggest correction
See an error? Suggest correction

First synthesized in 1932, it was briefly sold as Permonid in Switzerland before withdrawal by 1952.[1] It resurfaced in Russia around 2003 as "krokodil" — cooked from codeine and household chemicals — driving an epidemic reaching an estimated 100,000 users.[2] Russia restricted codeine sales in 2012, rapidly cutting use; desomorphine remains among the most heavily restricted opioids internationally.

Subjective effects include euphoria, deep sedation, pain suppression, physical warmth, and rapid erasure of anxiety. The experience is defined by speed — an intense rush that crests and crashes quickly, pushing dependent users into a relentless redosing cycle.[3] Nausea, respiratory depression, and compulsive redosing are characteristic unwanted effects.

Desomorphine produces severe physical dependence, and the margin between an effective and fatal dose is presumed extremely narrow.[4] The short half-life demands multiple daily injections, accelerating tolerance; street krokodil injects toxic contaminants with each dose, causing catastrophic tissue and bone destruction.[5] No controlled human studies exist — the evidence rests on historical case reports, animal data, and reviews of the krokodil epidemic.

History[edit]

Discovery

Desomorphine was first synthesized in 1932 by Lyndon Frederick Small, funded by the US National Research Council.[1] Earlier German work by Knoll AG had preceded him without gaining wide recognition.[1] Small patented the compound in 1934.

Clinical use and withdrawal

Hoffmann-La Roche marketed desomorphine as Permonid in Switzerland from around 1940 as a post-operative painkiller with faster onset and less nausea than morphine.[6][7] It was withdrawn in 1952 due to a short shelf life and high abuse liability.[7] International prohibition followed, with placement in Schedule IV of the UN Single Convention on Narcotic Drugs (1961) and Schedule I in the United States.

The krokodil epidemic

Street-synthesized desomorphine emerged in Russia around 2003–2004,[3][8] driven by heroin shortages and codeine available over the counter at roughly one-third the cost per dose.[2] By 2011 an estimated 100,000 or more people injected krokodil in Russia and approximately 20,000 in Ukraine.[2] Russia restricted codeine to prescription-only in June 2012, producing a rapid decline;[8] no toxicologically confirmed cases have been documented in the United States,citation needed and no confirmed detections were reported in Canada as of 2013.[9]

Chemistry[edit]

Structural class

Desomorphine belongs to the morphinan class, sharing the core scaffold with morphine, codeine, and heroin. Two modifications set it apart: the C-6 hydroxyl group is removed and the C-7,8 double bond is saturated. These changes increase fat-solubility, allowing faster passage across the blood-brain barrier than morphine.[1]

Molecular properties

Its molecular formula is C₁₇H₂₁NO₂ (molecular weight 271.35 g/mol). A hydroxyl group at C-3 is retained and contributes to opioid receptor binding; the absent C-6 hydroxyl accounts for the faster onset relative to morphine.[6] Street-synthesized krokodil contains at most approximately 75% desomorphine — the remainder is toxic synthesis residue injected alongside it.[5][3]

Pharmacology[edit]

Mechanism of action

Desomorphine is a potent full agonist at mu-opioid receptors, with weaker activity at other opioid receptors.[6][5] Activating these receptors reduces nerve excitability — pain signaling drops, breathing slows, and the reward circuit releases dopamine, producing analgesia, respiratory depression, and euphoria.[10] Potency is estimated at 8–10 times that of morphine, based on comparative animal testing.[1][4]

The faster onset compared to morphine comes from greater fat-solubility: without the C-6 hydroxyl group, desomorphine crosses the blood-brain barrier more quickly.[1]

Pharmacokinetics

No controlled human pharmacokinetic study for desomorphine has been published. All parameters described here are derived from clinical descriptions and structural-structural analog inference, not from direct measurement.

Intravenous injection is the only documented route,[3][2][5][4] producing onset within seconds to minutes. Duration is shorter than morphine — dependent users inject multiple times daily, versus the 1–3 daily injections typical of heroin.[3][2] No precise half-life or distribution data exist for humans; liver processing via glucuronidation is the expected elimination route, inferred from related morphinan compounds.[11][12] Oral dose estimates appearing in some sources could not be verified against any primary source.safety citation needed

Neuroscience[edit]

Where it acts

Desomorphine engages the same brain systems as all potent μ-opioid agonists. In the brain's reward circuit, it releases a surge of dopamine, producing intense euphoria.[10] In the brainstem, it depresses the breathing center — the primary mechanism of opioid overdose death. Its 8–10-fold potency advantage over morphine[1] means these effects occur at lower doses.

Why it matters

The rapid onset and short duration maximize addictive potential. A fast dopamine spike followed by rapid collapse creates a disproportionately strong drive to redose, consistent with the compulsive redosing documented in krokodil users.[3] Frequent cycling between intoxication and early withdrawal accelerates receptor desensitization and deepens the brain's opioid deficit when the drug is discontinued.[10]

Subjective Effects[edit]

Summary

Desomorphine is a fast-acting, fast-fading opioid. Intravenous injection produces an almost immediate surge of euphoria, warmth, and profound relief — pain disappears, anxiety dissolves, and the body settles into deep sedation. The peak is intense but brief, and its rapid collapse is the defining quality of the experience.

Within the opioid class, desomorphine sits closest to short-acting injectable opioids like fentanyl rather than the more gradual arc of heroin. The rapid-onset, rapid-offset pattern generates stronger reinforcement than longer-acting opioids. No controlled subjective-effects study exists — all descriptions come from historical clinical notes and user reports confounded by krokodil's toxic contaminants.

Synthesized by Lyndon Frederick Small in 1932 and briefly marketed as Permonid in Switzerland, desomorphine was withdrawn from clinical use by 1952 due to high abuse liability.[1] The compound resurfaced as "krokodil" — crudely synthesized from codeine tablets — in a Russian epidemic that peaked around 2010–2012 with an estimated 100,000 or more users.[3] It remains a Schedule I controlled substance in the United States and is among the most heavily restricted opioids internationally.

Subjective effects include euphoria, sedation, pain suppression, and anxiolysis. The experience is defined by its brevity — an intense but rapidly fading wave of warmth and obliteration of distress that gives way to early withdrawal, driving relentless redosing cycles among dependent users.[4] Nausea, respiratory slowing, and compulsive redosing are characteristic unsought effects.

Desomorphine produces very high physical dependence, and no published LD50 or therapeutic index exists — the margin between an effective and fatal dose is presumed extremely narrow.[5] The short half-life accelerates tolerance development, demanding ever-more-frequent injection; the severe tissue destruction associated with krokodil is attributed primarily to toxic synthesis contaminants rather than the compound itself.[6] No controlled human pharmacology or toxicology data exist — the entire evidence base rests on historical clinical descriptions, animal studies, case reports, and epidemiological reviews of the krokodil phenomenon.

History[edit]

Discovery

Desomorphine was first synthesized in 1932 by Lyndon Frederick Small at the University of Virginia, funded by the US National Research Council.[1] Small patented the compound in 1934, though earlier German work by Knoll AG (circa 1920) had preceded his synthesis without gaining wide recognition in English-language literature.[1] The synthesis involved chlorination of morphine derivatives followed by catalytic hydrogenation — a multi-step procedure that removed the C-6 hydroxyl and saturated the C-7,8 double bond.

Clinical use and withdrawal

Hoffmann-La Roche marketed desomorphine as Permonid in Switzerland beginning around 1940, positioning it as a post-operative analgesic with faster onset, shorter duration, and less nausea than morphine.[7][8] The drug was withdrawn from the Swiss market in 1952 due to a short shelf life and high abuse liability.[8] International prohibition followed: desomorphine was placed in Schedule IV of the UN Single Convention on Narcotic Drugs (1961), the most restrictive tier, and classified as Schedule I in the United States.

The krokodil epidemic

Street-synthesized desomorphine, known as "krokodil," emerged in Russia around 2003–2004,[4][9] driven by heroin supply disruptions, over-the-counter codeine availability, and a cost roughly three times lower than heroin per dose.[3] By 2011 an estimated 100,000 or more people injected krokodil in Russia and approximately 20,000 in Ukraine.[3] Russia reclassified codeine as prescription-only in June 2012, producing a rapid decline in use,[9] though the practice did not disappear entirely. No toxicologically confirmed krokodil cases have been documented in the United States,citation needed and no confirmed detections were reported in Canada as of 2013.[10]

Chemistry[edit]

Structural class

Desomorphine belongs to the morphinan chemical class, sharing the 4,5-epoxymorphinan scaffold with morphine, codeine, and heroin. It differs from morphine by two structural changes: removal of the C-6 hydroxyl group ("desoxy") and saturation of the C-7,8 double bond ("dihydro"). These modifications substantially increase lipophilicity, allowing faster passage across the blood-brain barrier and more rapid entry into the central nervous system.[1]

Molecular properties

Molecular formulaC₁₇H₂₁NO₂
Molecular weight271.35 g/mol

The morphinan ring system consists of a phenanthrene core fused with a piperidine ring and an oxygen bridge (the 4,5-epoxy bridge). The C-3 phenolic hydroxyl is retained and contributes to opioid receptor binding, while the absent C-6 hydroxyl accounts for the enhanced lipophilicity and faster onset relative to morphine.[7]

Stereochemistry

Desomorphine has four stereocenters (4R, 4aR, 7aS, 12bS). The (minus)-isomer is the pharmacologically active form, analogous to natural (minus)-morphine.[1] Street-synthesized krokodil, produced by crude reduction from codeine, likely contains a variable mixture of stereoisomers with undefined purity.citation needed

Clandestine synthesis

The street synthesis of krokodil bears little resemblance to laboratory preparation. Clandestine production starts with codeine-containing tablets and uses red phosphorus (from matchbox strikers), iodine, organic solvents (lighter fluid, paint thinner), and alkali solutions as reagents.[6] The resulting product is a crude mixture: desomorphine content ranges from trace levels to approximately 75%, with the remainder consisting of unreacted codeine, synthesis intermediates, residual phosphorus, iodine, solvents, heavy metals, and tablet binders.[7][6][4] All of these contaminants are injected intravenous when the mixture is used.

Pharmacology[edit]

Mechanism of action

Desomorphine is a potent full agonist at the mu-opioid receptor (μ-opioid), with weaker activity at kappa- and delta-opioid receptors.[7][6] Activation of MOR triggers a signaling cascade that reduces neuronal excitability: intracellular energy signaling drops, potassium channels open, and calcium channels close, collectively suppressing neurotransmitter release across pain, reward, and autonomic circuits.[2]

This mechanism produces the full spectrum of opioid effects — analgesia, sedation, euphoria, respiratory depression, slowed gut motility, and pinpoint pupils.[2] No published binding affinity values exist for desomorphine at any opioid receptor subtype; its potency estimate of 8–10 times that of morphine derives from comparative analgesic testing in animal models.[1][7][5]

The potency advantage is attributed to increased lipophilicity: without the C-6 hydroxyl group present in morphine, desomorphine crosses the blood-brain barrier faster and in greater quantity.[1]

Pharmacokinetics

No controlled human pharmacokinetic study for desomorphine has been published. All parameters described here are derived from clinical descriptions and structural-structural analog inference, not from direct measurement.

Desomorphine reaches the brain faster than morphine owing to its higher lipophilicity.[7][1] By the intravenous route — the only route documented in the clinical and epidemiological literature — onset is expected within seconds to minutes, consistent with other fat-soluble opioids.

Duration of action is shorter than morphine. This brevity drives the pattern observed among dependent krokodil users: injecting multiple times daily, compared with the 1–3 daily injections typical of heroin dependence.[4][3] No precise half-life, peak concentration, or volume of distribution values have been published for desomorphine in humans.

No human metabolic study exists. Based on the behavior of related morphinan compounds, liver processing via glucuronidation is expected as a major elimination pathway, with possible involvement of CYP3A4 and CYP2D6 enzymes — but this is inferred from class pharmacology, not substance-specific data.[11][12]

All published reports describe intravenous injection as the primary and near-exclusive route of administration.[4][3][6][5] The original clinical formulation (Permonid) was also parenteral. Oral dose estimates appearing in some tertiary references could not be verified against any primary source and should be treated as unconfirmed.safety citation needed

Neuroscience[edit]

Where it acts

Desomorphine engages the same brain systems as all potent μ-opioid agonists. In the ventral tegmental area, it suppresses inhibitory neurons and releases a surge of dopamine into the reward circuit, producing intense euphoria.[2] In the brainstem's pain-processing regions, it activates a descending inhibitory pathway that suppresses pain signals at the spinal cord level — its 8–10-fold potency advantage over morphine[1] means this suppression occurs at lower doses. The same brainstem action depresses the breathing center, the primary mechanism of opioid overdose death.

Why it matters

Desomorphine's rapid onset and short duration create a pharmacokinetic profile that maximizes addictive potential. The incentive salience model distinguishes between "liking" (hedonic pleasure) and "wanting" (motivational drive to obtain the drug) — rapid dopamine spikes followed by rapid decline generate disproportionately strong wanting, consistent with the compulsive redosing documented in krokodil users.[4] Frequent cycling between intoxication and early withdrawal also accelerates molecular tolerance adaptations: receptor desensitization, internalization, and compensatory upregulation of cellular signaling.[2] Chronic use depletes endogenous opioid tone, deepening the dysphoria when the drug is discontinued.[2]

Subjective Effects[edit]

Summary

The desomorphine experience is that of a potent, fast-acting, fast-fading opioid. Intravenous injection — the only documented route — produces an immediate rush of euphoria and physical warmth, followed by deep sedation, analgesia, and anxiolysis. The defining quality is the speed of the cycle: peak effects arrive almost instantly and dissipate quickly, giving way to early withdrawal symptoms that create an urgent drive to redose. Set and setting influence the psychological coloring of the experience, but the pharmacokinetic pressure toward compulsive redosing dominates accounts of dependent use.[5]

Within the opioid class, desomorphine sits closest to short-acting injectable opioids like fentanyl rather than the moderate-duration profile of heroin. The rapid-onset, rapid-offset pattern generates stronger reinforcement signaling than longer-acting opioids, contributing to exceptionally high abuse liability. No controlled subjective-effects study has been published; all phenomenological descriptions derive from historical clinical notes and user reports confounded by toxic contaminants in street krokodil.

Effect Grid

Dose Level:
Description

At common doses, the full opioid profile manifests: pronounced euphoria — both cognitive and tactile — with a strong sense of warmth, deep anxiety suppression, and substantial pain suppression. Sedation intensifies; the characteristic opioid 'nod' (oscillation between wakefulness and drowsy semiconsciousness) may begin. Internal hallucinations in the form of vivid dreamlike imagery can emerge during nodding episodes.

Physically, pupil constriction is marked. Constipation, appetite suppression, and sexual arousal suppression are typical. Respiratory depression becomes clinically relevant — breathing is noticeably slowed and shallow. Nausea is reported less frequently than with equivalent morphine doses.

The compulsive redosing urge is strong at this level due to the rapid offset of effects. Users should be aware that the subjective experience fades quickly, but respiratory depression may persist.

Modeled from the effect's dose-dependence curve — not per-substance measurements.

Perception(5)likelihood · intensity
Dreaming suppression
possible
Visual acuity suppression
possible
Visual haze / noise
possible
Spatial disorientation
possible
Visual processing suppression
rare
Body(29)likelihood · intensity
Constipation
likely
Pain suppression
likely
Pupil constriction
likely
Sedation
likely
Body high
likely
Muscle relaxation
likely
Respiratory depression!
likely
Motor control impairment!
possible
Temperature dysregulation!
possible

Sedation · Body high · Muscle relaxation · Physical fatigue · Bodily heaviness · Insomnia · Muscle tension · Nausea · Restlessness · Tactile euphoria · Trembling · Watery eyes · Yawning · Dizziness · Excessive sweating · Sexual arousal suppression · Temperature dysregulation · Appetite suppression · Diarrhea · Dry mouth · Tingling / electric sensations · Vomiting · Nystagmus (eye wobbles) · Bodily dissociation

Physical fatigue · Bodily heaviness · Insomnia · Muscle tension · Nausea · Restlessness · Tactile euphoria · Trembling · Watery eyes · Yawning · Dizziness · Excessive sweating · Sexual arousal suppression · Appetite suppression · Diarrhea · Dry mouth · Tingling / electric sensations · Vomiting · Nystagmus (eye wobbles) · Bodily dissociation

Thinking(17)likelihood · intensity
Cognitive impairment
likely
Compulsive redosing urge!
likely
Analysis suppression
possible
Cognitive euphoria
possible
Cognitive fatigue
possible
Decision impairment!
possible
Focus suppression
possible
Information processing suppression
possible
Amnesia!
v.rare

Cognitive fatigue · Focus suppression · Information processing suppression · Motivation suppression · Thought deceleration · Memory suppression · Cognitive dysphoria · Confusion · Language suppression · Memory fragmentation · Thought disorganization · Amnesia

Motivation suppression · Thought deceleration · Memory suppression · Cognitive dysphoria · Confusion · Language suppression · Memory fragmentation · Thought disorganization

Feeling(10)likelihood · intensity
Euphoria
likely
Anxiety suppression
likely
Anxiety
possible
Emotional suppression
possible
Irritability
possible
Anhedonia
possible
Depression!
possible
Dysphoria
possible
Paranoia!
rare

Emotional suppression · Irritability · Anhedonia · Dysphoria · Empathy suppression

Empathy suppression

Self(10)likelihood · intensity
Craving
likely
Communication suppression
possible
Sociability suppression
possible
Social disconnection
possible
Depersonalization
possible
Disinhibition
possible
Derealization
possible
Sociability enhancement
possible
Self-control suppression!
rare

Depersonalization · Disinhibition · Derealization · Sociability enhancement · Cognitive disconnection

Cognitive disconnection

Time(2)likelihood · intensity
Time alteration
possible
Temporal disorientation
possible
Awareness(1)likelihood · intensity
Reality testing impairment!
v.rare
report missing effect
Likelihood: how common this effect is at the selected dose level.This effect has safety implications — review before use.

Timeline

Safety[edit]

Harm
Acute toxicity
Critical
Chronic toxicity
High
Withdrawal
Severe
Tolerance buildup
rapid
Tolerance reset
14 days
Dependence
Physical
High
Psychological
High
Compulsive redosing
High
Dose escalation
High
Cross-tol.
opioids
Risk Shape
TOXPHYPSYWDRREDTOL

Toxicity

Acute opioid toxicity

Desomorphine carries all the risks of a potent μ-opioid agonist. The primary danger is respiratory depression — breathing slows and can stop, causing death. At 8–10 times the potency of morphine,[1][6] the margin between an effective and fatal dose is presumed extremely narrow. No LD50 value has been published for any species,safety citation needed and no therapeutic index exists.safety citation needed

Naloxone is expected to reverse desomorphine-induced respiratory depression, as with all mu-opioid agonists. The dose required relative to heroin reversal is unknown.safety citation needed

Contaminant toxicity (krokodil)

The catastrophic tissue damage in krokodil users is caused primarily by toxic synthesis byproducts — phosphorus compounds, iodine, organic solvents, and heavy metals — not by pharmaceutical-grade desomorphine.[5][3]

Skin and soft tissue: Blood-vessel inflammation, abscesses, ulceration, gangrene, and green-gray skin death — the "crocodile skin" appearance — are the most common injuries.[2][14][3] Limb amputations have been documented.[2] Skin death has been reported after a single injection.[14]

Bone: Jaw bone death is the most frequently documented bone injury, with a systematic review identifying 101 cases across 30 studies.[15] The lower jaw was affected in 52.5% of a 40-patient series.[16] Phosphorus compounds in the synthesis residue are the likely cause.[5][17]

Heart and other organs: Fatal heart-lining inflammation with heart failure has been documented in a chronic krokodil user.[18] Repeated krokodil exposure in rats produced markers of kidney and heart tissue damage.[13]

Infections: Krokodil injection is associated with high rates of bacterial heart-valve infection, HIV, and hepatitis C through shared equipment and non-sterile technique.[19][20]

Mortality: Deaths from chronic krokodil use are documented.[18] Reports of dramatically shortened life expectancy (1–2 years from first injection) appear in secondary literature but have not been confirmed in controlled studies.citation needed

Psychological Risks

No controlled studies of desomorphine's psychological effects exist. The short duration drives a cycle of intoxication and early withdrawal that repeats multiple times daily, producing rapid swings between euphoria and acute dysphoria and consuming the user's time entirely.[3][2]

  • Compulsive redosing: The short duration drives a cycle that repeats multiple times daily.[3][2]
  • Emotional instability: Rapid alternation between opioid euphoria and dysphoria produces escalating distress.
  • Cognitive impairment: Repeated intoxication and medical consequences impose significant cognitive burden.
  • Social collapse: The krokodil epidemic was associated with severe marginalization — users unable to maintain employment, housing, or relationships.[2]

Tolerance & Dependence

Desomorphine produces rapid tolerance and very high physical dependence, driven by its short half-life and potent mu-opioid agonism.[1][21][4] Krokodil users inject multiple times daily,[3][2] accelerating both tolerance and physical dependence beyond what longer-acting opioids produce. Cross-tolerance to other opioids is expected.

Withdrawal is expected to be opioid-typical: tearing, runny nose, muscle pain, agitation, insomnia, diarrhea, vomiting, and craving. The short half-life means withdrawal onset is expected within hours of the last dose.safety citation needed Treatment follows standard opioid dependence protocols (methadone or buprenorphine), though no desomorphine-specific treatment literature exists.

4LETHAL
39DANGEROUS
12CAUTION
5UNGRADED
60 rules2 SOURCE-VERIFIED4 EDITOR-REVIEWED

No published drug interaction studies specific to desomorphine exist. All interactions below are inferred from mu-opioid class pharmacology.safety citation needed

Depressant combinations: Combining with benzodiazepines, alcohol, barbiturates, sleep medications, gabapentinoids, or other opioids produces additive respiratory depression — the most dangerous interaction for any opioid and the leading cause of opioid overdose death globally.

MAOIs: Combining opioids with monoamine oxidase inhibitors carries risk of severe, potentially fatal crisis. Whether desomorphine has serotonergic activity is unknown, but the interaction is treated as an absolute contraindication.

Opioid antagonists: Naloxone and naltrexone block desomorphine at the mu-opioid receptor. Naloxone reverses overdose; naltrexone provides sustained blockade for relapse prevention.

Liver enzyme interactions: If desomorphine is processed by CYP3A4 and CYP2D6 (inferred from class, not confirmed), enzyme inhibitors like ketoconazole or fluoxetine could raise desomorphine levels, and inducers like rifampicin could lower them. This interaction is entirely theoretical.

Contraindications

6 known
4ABSOLUTE
2RELATIVE

No substance-specific data exist. The following are inferred from mu-opioid class pharmacology:

  • Breathing problems: Pre-existing respiratory conditions (COPD, severe asthma, sleep apnea) substantially increase the risk of fatal respiratory depression.safety citation needed
  • Concurrent depressant use: Active use of benzodiazepines, alcohol, barbiturates, or other opioids — absolute contraindication due to additive respiratory depression.
  • MAOI use: Concurrent or recent (within 14 days) use of monoamine oxidase inhibitors — absolute contraindication.
  • Head injury or raised brain pressure: Opioid-induced respiratory depression raises skull pressure; sedation and pinpoint pupils mask neurological assessment.
  • Bowel obstruction: Opioids slow gut motility; use during bowel obstruction risks perforation.
  • Known allergy to morphinan opioids.

Harm Reduction[edit]

Forms & Identification

Reagent ResultsNot recorded+ add reagent results
AppearanceNot recorded+ add appearance
Red FlagsNot recorded+ add red flags

No pharmaceutical-grade desomorphine is manufactured anywhere in the world. All currently available desomorphine is clandestinely synthesized krokodil — a crude mixture with highly variable potency and heavy contaminant loads. Standard reagent test kits are not designed to identify desomorphine or distinguish it from other opioids in a crude mixture.

The variable desomorphine content (trace to ~75%) means no two batches can be treated as equivalent. Even if the opioid component were somehow standardized, every injection would still deliver phosphorus, iodine, solvents, and heavy metals. There is no form of krokodil that can be considered clean without laboratory-grade purification.

Guidelines

  • Never use alone. Opioid overdose kills by stopping breathing while the user is unconscious. A person present who can call for help and administer naloxone is the single most important risk reduction measure.
  • Have naloxone immediately accessible. Nasal naloxone (Narcan) should be within arm's reach of anyone present during use. Multiple doses may be needed.
  • Start with less. Given the unknown and variable potency of any krokodil preparation, use the smallest possible amount and wait before redosing.
  • Use sterile equipment. New, sterile syringes and injection supplies for every injection. Never share needles, cookers, filters, or water.
  • Filter the solution. Use a sterile micron filter (wheel filter) if available — this does not remove dissolved contaminants but reduces particulate matter entering the bloodstream.
  • Rotate injection sites and use proper technique. Vascular damage from krokodil contaminants is cumulative. Clean the injection site with alcohol swabs before and after.
  • Do not combine with other depressants. No alcohol, benzodiazepines, sleep medications, or other opioids.

Set & Setting

The short duration means a dependent user must redose multiple times daily. Any setting where redosing cannot be performed safely — or where the user may lose consciousness without supervision — substantially increases overdose risk. A sober person present during injection and through the immediate post-injection period is critical: respiratory depression from an opioid this potent can progress to fatal apnea within minutes.

Aftercare & integration. The post-use period following desomorphine is dominated by withdrawal, not afterglow. Hydration, nutrition, and rest are immediate priorities. Injection-site wounds should be cleaned and monitored for redness, swelling, warmth, or pus — any developing skin discoloration or tissue hardening requires urgent medical evaluation.

For those attempting to reduce or stop use, withdrawal begins faster than with heroin or morphine. Medical supervision is strongly recommended — the rapid onset of severe withdrawal can drive immediate relapse. Opioid substitution therapy (methadone, buprenorphine) provides a stable pharmacological floor that prevents the withdrawal-redosing cycle.

Recovery & Support

Desomorphine dependence responds to the same evidence-based treatments used for other opioid use disorders. Medication-assisted treatment (MAT) with methadone or buprenorphine is the highest-evidence intervention, stabilizing opioid receptor activity and eliminating the withdrawal-driven redosing cycle. Naltrexone (oral or extended-release injection) provides opioid blockade for those who have completed detoxification.

Peer support programs (Narcotics Anonymous, SMART Recovery) complement medical treatment. For krokodil users, tissue damage, bone death, and infections often require concurrent surgical, dental, and infectious-disease care alongside addiction treatment.[22][16]

Recovery resources, crisis lines, and support pathways → View all

Emergency Response

Recognizing an emergency: Slow, shallow, or stopped breathing; blue or gray lips and fingertips; gurgling or choking sounds; unresponsiveness to voice or pain; pinpoint pupils in an unconscious person. Any of these signals a life-threatening opioid overdose.

Immediate steps:

  • Call emergency services immediately.
  • Administer naloxone (nasal spray or injection) if available. If no response in 2–3 minutes, give a second dose.
  • Place the person in the recovery position (on their side) to prevent choking on vomit.
  • Stay with the person until help arrives. If breathing stops entirely, begin rescue breathing or CPR.
  • Do NOT induce vomiting. Do NOT leave the person alone.

What to tell the dispatcher: "Possible opioid overdose" — state the substance if known, the approximate time and amount used, and current symptoms (not breathing, unconscious, blue lips). Good Samaritan laws in many jurisdictions protect callers from prosecution for drug-related offenses when seeking emergency help.

Reversal agent: Naloxone (Narcan) reverses μ-opioid agonist overdose. Desomorphine's short duration means naloxone's effect may outlast the drug, but if a large dose has been taken or other depressants are on board, re-sedation is possible. Monitor continuously until emergency services arrive.

Safety[edit]

Harm
Acute toxicity
Critical
Chronic toxicity
High
Withdrawal
Severe
Tolerance buildup
rapid
Tolerance reset
14 days
Dependence
Physical
High
Psychological
High
Compulsive redosing
High
Dose escalation
High
Cross-tol.
opioids
Risk Shape
TOXPHYPSYWDRREDTOL

Toxicity

Acute opioid toxicity

Desomorphine carries all the risks of a potent μ-opioid agonist: respiratory depression (the primary cause of opioid overdose death), cardiovascular depression, aspiration from vomiting while unconscious, and oxygen deprivation to organs. At 8–10 times the potency of morphine,[1][7] the margin between an effective and a fatal dose is presumed extremely narrow. No LD50 value has been published for any species,safety citation needed and no published therapeutic index exists.safety citation needed

Naloxone is expected to reverse desomorphine-induced respiratory depression, as with all mu-opioid agonists. No published case series documents naloxone reversal of desomorphine overdose specifically; the dose required relative to heroin reversal is unknown.safety citation needed

Contaminant toxicity (krokodil)

The catastrophic tissue damage documented in krokodil users is attributed primarily to toxic synthesis byproducts — phosphorus compounds, iodine, organic solvents, alkali residues, and heavy metals — not to pharmaceutical-grade desomorphine.[6][4]

Skin and soft tissue: Blood-vessel inflammation, abscesses, ulceration, gangrene, and skin death with green-gray discoloration — the "crocodile skin" appearance — are the most commonly reported injuries.[3][14][4] Limb amputations have been documented.[3] Skin death has been reported after a single injection.[14]

Bone: Jaw bone death (osteonecrosis) is the most frequently documented bone injury, with a systematic review identifying 101 cases across 30 studies.[15] The lower jaw was affected in 52.5% of a 40-patient series, the upper jaw in 27.5%, and both in 20%.[16] The mechanism likely involves direct chemical poisoning of bone by phosphorus compounds.[6][17]

Heart: Fatal inflammation of the heart lining with heart failure has been documented in a chronic krokodil user; desomorphine metabolites were confirmed at autopsy.[18]

Kidney and heart (animal data): Repeated krokodil administration in rats produced markers of tissue damage, oxidative stress in kidney and heart tissue, and cardiac congestion.[13]

Infections: Krokodil injection is associated with high rates of bacterial heart-valve infection, HIV transmission, and hepatitis C through shared equipment and non-sterile technique.[19][20]

Mortality: Deaths from chronic krokodil use have been documented in case reports.[18] Reports of dramatically shortened life expectancy (1–2 years from first injection) appear in secondary literature but have not been confirmed in controlled studies.citation needed

Psychological Risks

No controlled studies of desomorphine's psychological effects exist. Risks are inferred from opioid class pharmacology and clinical observations of krokodil-dependent populations:

  • Compulsive redosing: The short duration drives a cycle of intoxication and early withdrawal that repeats multiple times daily, consuming the user's time and resources entirely.[4][3]
  • Emotional instability: Rapid alternation between opioid euphoria and acute dysphoria produces escalating psychological distress.
  • Cognitive impairment: Repeated intoxication and the medical consequences of krokodil injection together impose significant cognitive burden, though no neuropsychological studies specific to desomorphine users exist.
  • Social collapse: The krokodil epidemic was associated with severe marginalization — users unable to maintain employment, housing, or relationships.[3]

Tolerance & Dependence

Desomorphine produces rapid tolerance driven by its short half-life and potent mu-opioid agonism. Krokodil users were documented injecting multiple times per day,[4][3] and this dosing frequency accelerates tolerance development and physical dependence beyond what longer-acting opioids produce.

Dependence liability is rated very high across multiple reviews.[1][21][5] The combination of high potency, rapid onset, and short duration creates reinforcement patterns in the highest category of abuse liability among opioids. Cross-tolerance to other opioids is expected.

No controlled study of desomorphine withdrawal exists. The expected syndrome is opioid-typical: tearing, runny nose, yawning, goosebumps, muscle pain, agitation, insomnia, diarrhea, vomiting, low mood, and craving. Given the short half-life, withdrawal onset is expected within hours of the last dose.safety citation needed Treatment would follow standard opioid dependence protocols (methadone or buprenorphine substitution), though no desomorphine-specific treatment literature has been published.

4LETHAL
39DANGEROUS
12CAUTION
5UNGRADED
60 rules2 SOURCE-VERIFIED4 EDITOR-REVIEWED

No published drug interaction studies specific to desomorphine exist. All interactions below are inferred from mu-opioid agonist class pharmacology.safety citation needed

Depressant combinations: Co-use with benzodiazepines, alcohol, barbiturates, sleep medications, gabapentinoids, or other opioids produces additive or synergistic respiratory depression — the most dangerous interaction class for any opioid and the leading cause of opioid overdose death globally.

MAOIs: The combination of monoamine oxidase inhibitors with opioids is a class-wide contraindication carrying risk of severe crisis. Whether desomorphine has serotonergic activity is unknown, but the MAOI-opioid interaction is considered potentially fatal regardless of the specific opioid.

Opioid antagonists: Naloxone and naltrexone competitively block desomorphine at the mu-opioid receptor. Naloxone is the standard overdose reversal agent; naltrexone provides sustained blockade for relapse prevention.

Liver enzyme interactions: If desomorphine is processed by CYP3A4 and CYP2D6 (inferred from class, not confirmed), drugs that inhibit these enzymes (e.g., ketoconazole, fluoxetine, paroxetine) could increase desomorphine levels, and drugs that induce them (e.g., rifampicin, carbamazepine) could decrease them. This interaction is entirely theoretical for desomorphine.

Contraindications

6 known
4ABSOLUTE
2RELATIVE

No substance-specific contraindication data exist. The following are inferred from mu-opioid agonist class pharmacology:

  • Breathing problems: Pre-existing respiratory conditions (COPD, severe asthma, sleep apnea) substantially increase the risk of fatal respiratory depression with any potent opioid.safety citation needed
  • Concurrent depressant use: Active use of benzodiazepines, alcohol, barbiturates, or other opioids is an absolute contraindication due to additive respiratory depression.
  • MAOI use: Concurrent or recent (within 14 days) use of monoamine oxidase inhibitors is an absolute contraindication.
  • Head injury or raised brain pressure: Opioid-induced respiratory depression raises pressure inside the skull; sedation and pinpoint pupils mask neurological assessment.
  • Bowel obstruction: Opioids slow gut motility; use during bowel obstruction risks perforation.
  • Known allergy to morphinan opioids.

Harm Reduction[edit]

Forms & Identification

Reagent ResultsNot recorded+ add reagent results
AppearanceNot recorded+ add appearance
Red FlagsNot recorded+ add red flags

No pharmaceutical-grade desomorphine is manufactured anywhere in the world. All currently available desomorphine exists as clandestinely synthesized "krokodil" — a crude mixture with wildly variable potency and heavy contaminant loads. Standard reagent testing kits are not designed to identify desomorphine or distinguish it from other opioids in a crude mixture. The extreme variability in desomorphine content (trace to ~75%) means that no two batches can be assumed equivalent, and dosing by volume or appearance is unreliable.

The presence of phosphorus, iodine, solvents, and heavy metals in krokodil means that even if the opioid component were somehow standardized, the injection would still deliver toxic contaminants. There is no form of krokodil that can be considered "clean" without laboratory-grade purification.

Guidelines

  • Never use alone. Opioid overdose kills by stopping breathing while the user is unconscious. A person present who can call for help and administer naloxone is the single most important risk reduction measure.
  • Have naloxone immediately accessible. Nasal naloxone (Narcan) should be within arm's reach of anyone present during use. Multiple doses may be needed.
  • Start with less. Given the unknown and variable potency of any krokodil preparation, use the smallest possible amount and wait before redosing.
  • Use sterile equipment. New, sterile syringes and injection supplies for every injection. Never share needles, cookers, filters, or water.
  • Filter the solution. Use a sterile micron filter (wheel filter) if available — this does not remove dissolved contaminants but reduces particulate matter entering the bloodstream.
  • Rotate injection sites and use proper technique. Vascular damage from krokodil contaminants is cumulative. Clean the injection site with alcohol swabs before and after.
  • Do not combine with other depressants. No alcohol, benzodiazepines, sleep medications, or other opioids.

Set & Setting

The short duration of desomorphine effects means that a user in a dependent pattern will need to redose multiple times per day. Any setting where redosing cannot be performed safely — or where the user may lose consciousness without supervision — substantially increases overdose risk. A sober companion present during injection and through the immediate post-injection period is critical, as respiratory depression from an opioid of this potency can progress to fatal apnea within minutes.

Aftercare & integration. The post-use period following desomorphine is dominated by withdrawal, not afterglow. Hydration, nutrition, and rest are immediate priorities. Injection-site wounds should be cleaned and monitored for signs of infection — redness, swelling, warmth, or pus — and any developing skin discoloration or tissue hardening requires urgent medical evaluation.

For users attempting to reduce or stop use, the withdrawal timeline is faster than with heroin or morphine. Medical supervision is strongly recommended, as the rapid onset of severe withdrawal symptoms can drive immediate relapse. Opioid substitution therapy (methadone, buprenorphine) provides a stable pharmacological floor that prevents the withdrawal-redosing cycle.

Recovery & Support

Desomorphine dependence responds to the same evidence-based treatments used for other opioid use disorders. Medication-assisted treatment (MAT) with methadone or buprenorphine is the highest-evidence intervention, stabilizing opioid receptor activity and eliminating the withdrawal-driven redosing cycle. Naltrexone (oral or extended-release injection) provides opioid blockade for those who have completed detoxification.

Peer support programs (Narcotics Anonymous, SMART Recovery) complement medical treatment. For krokodil users specifically, the medical complications — tissue damage, bone death, infections — often require concurrent surgical, dental, and infectious-disease care alongside addiction treatment.[22][16]

Recovery resources, crisis lines, and support pathways → View all

Emergency Response

Recognizing an emergency: Slow, shallow, or stopped breathing; blue or gray lips and fingertips; gurgling or choking sounds; unresponsiveness to voice or pain; pinpoint pupils in an unconscious person. Any of these signals a life-threatening opioid overdose.

Immediate steps:

  • Call emergency services immediately.
  • Administer naloxone (nasal spray or injection) if available. If no response in 2–3 minutes, give a second dose.
  • Place the person in the recovery position (on their side) to prevent choking on vomit.
  • Stay with the person until help arrives. If breathing stops entirely, begin rescue breathing or CPR.
  • Do NOT induce vomiting. Do NOT leave the person alone.

What to tell the dispatcher: "Possible opioid overdose" — state the substance if known, the approximate time and amount used, and current symptoms (not breathing, unconscious, blue lips). Good Samaritan laws in many jurisdictions protect callers from prosecution for drug-related offenses when seeking emergency help.

Reversal agent: Naloxone (Narcan) reverses μ-opioid agonist overdose. Desomorphine's short duration means that naloxone’s effect may outlast the drug, but if the user has taken a large dose or has other depressants on board, re-sedation is possible. Monitor continuously until emergency services arrive.

Frequently asked questions

What is Desomorphine?

Desomorphine is a semi-synthetic morphinan opioid and potent mu-opioid receptor agonist, approximately 8–10 times more potent than morphine. First synthesized in 1932, it gained notoriety as "krokodil" during a Russian street-drug epidemic peaking around 2010–2012.

How long does Desomorphine last?

Total duration by route of administration — Intravenous: 1 – 3 hours. Ranges vary with dose and individual factors; see the duration table for onset, peak, and after-effect phases.

Where can I find dosage information for Desomorphine?

Psychedex publishes a dosage table for Desomorphine on this page covering these routes of administration: oral, intravenous. Dose values are presented only in that table, always alongside their route of administration.

What are dangerous combinations with Desomorphine?

The highest-severity documented interactions for Desomorphine: Benzodiazepines, Barbiturates (Lethal), GHB, Baclofen (Lethal), GHB, GBL (Lethal), Local anesthetics (Lethal), 5-HTP, Tryptophan (Dangerous). See the interactions section for the full list with mechanisms and severity levels.

Is Desomorphine addictive?

Psychedex records tolerance and dependence data rather than a yes/no rating. Recorded tolerance indicators for Desomorphine: tolerance builds rapid; full reset takes 14 days; cross-tolerance develops with opioids. See the article's dependence and safety sections for recorded dependence data.

experience reports

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First-person accounts of subjective effects, timing, and outcomes — submitted for harm reduction.

references

  1. [1] 
    ^abcdefghiMella-Raipán J, Romero-Parra J, Recabarren-Gajardo G (2020) DARK Classics in Chemical Neuroscience: Heroin and Desomorphine — ACS Chemical Neuroscience doi:10.1021/acschemneuro.0c00262
  2. [2] 
    ^abcdefghijklGrund JP, Latypov A, Harris M (2013) Breaking worse: the emergence of krokodil and excessive injuries among people who inject drugs in Eurasia — International Journal of Drug Policy doi:10.1016/j.drugpo.2013.04.007
  3. [3] 
    ^abcdefghijkGahr M, Freudenmann RW, Hiemke C, Gunst IM, Connemann BJ, Schönfeldt-Lecuona C (2012) Desomorphine goes 'crocodile' — Journal of Addictive Diseases doi:10.1080/10550887.2012.735570
  4. [4] 
    ^abcdKatselou M, Papoutsis I, Nikolaou P, Spiliopoulou C, Athanaselis S (2014) A 'krokodil' emerges from the murky waters of addiction. Abuse trends of an old drug — Life Sciences doi:10.1016/j.lfs.2014.03.008
  5. [5] 
    ^abcdefAlves EA, Grund JP, Afonso CM, Netto AD, Carvalho F, Dinis-Oliveira RJ (2015) The harmful chemistry behind krokodil (desomorphine) synthesis and mechanisms of toxicity — Forensic Science International doi:10.1016/j.forsciint.2015.02.001
  6. [6] 
    ^abcdCalifornia Poison Control System (2023) Desomorphine (Krokodil) - California Poison Control System Link

references

  1. [1] 
    ^abcdefghijklMella-Raipán J, Romero-Parra J, Recabarren-Gajardo G (2020) DARK Classics in Chemical Neuroscience: Heroin and Desomorphine — ACS Chemical Neuroscience doi:10.1021/acschemneuro.0c00262
  2. [2] 
    ^abcdefVearrier D, Grundmann O (2021) Clinical Pharmacology, Toxicity, and Abuse Potential of Opioids — Journal of Clinical Pharmacology doi:10.1002/jcph.1923
  3. [3] 
    ^abcdefghijkGrund JP, Latypov A, Harris M (2013) Breaking worse: the emergence of krokodil and excessive injuries among people who inject drugs in Eurasia — International Journal of Drug Policy doi:10.1016/j.drugpo.2013.04.007
  4. [4] 
    ^abcdefghijGahr M, Freudenmann RW, Hiemke C, Gunst IM, Connemann BJ, Schönfeldt-Lecuona C (2012) Desomorphine goes 'crocodile' — Journal of Addictive Diseases doi:10.1080/10550887.2012.735570
  5. [5] 
    ^abcdeKatselou M, Papoutsis I, Nikolaou P, Spiliopoulou C, Athanaselis S (2014) A 'krokodil' emerges from the murky waters of addiction. Abuse trends of an old drug — Life Sciences doi:10.1016/j.lfs.2014.03.008
  6. [6] 
    ^abcdefgAlves EA, Grund JP, Afonso CM, Netto AD, Carvalho F, Dinis-Oliveira RJ (2015) The harmful chemistry behind krokodil (desomorphine) synthesis and mechanisms of toxicity — Forensic Science International doi:10.1016/j.forsciint.2015.02.001
Last updated Jun 4, 2026