WARNINGDANGER OF DEATH
High doses alone or ordinary doses in combination with other depressants can fatally stop breathing.
Codeine
Codeine is a naturally occurring opiate alkaloid found in the opium poppy (*Papaver somniferum*), first discovered by Pierre Jean Robiquet in 1832.citation needed It functions primarily as a prodrug of morphine, making it a relatively weak opioid in its own right. Codeine is used medically as an analgesic, antitussive, and antidiarrheal.1 It is frequently available over-the-counter in combination with acetaminophen or ibuprofencitation needed, and cold water extraction is commonly employed to separate codeine from these potentially harmful additives.
Dosage & Duration
Dosage
Doses are population estimates that vary widely between individuals.
Most individuals experience a ceiling effect for both analgesic and euphoric properties in the range of 300–500 mg, though some may find this threshold extends to approximately 600 mg due to individual variation. Doses beyond this point primarily increase the risk and severity of adverse effects rather than producing proportionally greater desired effects.
Duration
Subjective Effects
Legacy content. A statistically backed ontology from Mindstate Design Labs is coming soon.
Effects vary widely by individual, dose, and context.
Physical
The physical effects of codeine can be broken down into several components which progressively intensify proportional to dosage. The general head space of codeine is described by many as one of intense euphoria, relaxation, anxiety suppression and pain relief.
Cognitive
Pharmacology
Pharmacodynamics
Codeine functions primarily as a prodrug4, possessing relatively weak affinity for the μ-opioid receptor (MOR) on its own5 (Ki of approximately 1,500 nM in rat brain tissue). Its analgesic effects are largely mediated by its active metabolites morphine4 and codeine-6-glucuronide, both of which are substantially more potent MOR agonists. Codeine also acts as an agonist at κ-opioid and δ-opioid receptors, and suppresses the cough reflex through a direct action on the cough center in the medullacitation needed. Additionally, codeine has been reported to activate TLR4 signaling, which may contribute to increased pain sensitivity independently of its conversion to morphine.
Pharmacokinetics
Codeine is absorbed from the gastrointestinal tract, reaching peak plasma concentration approximately 60 minutes after oral administration.5 It is extensively metabolized in the liver, with approximately 70 to 80% of the ingested dose undergoing glucuronidation to codeine-6-glucuronide via UGT2B7 and UGT2B4.citation needed Approximately 5 to 10% is O-demethylated to morphine by CYP2D6, and about 10% is N-demethylated to norcodeine by CYP3A4.5 UGT2B7 further conjugates norcodeine and morphine to their corresponding 3- and 6-glucuronides. The plasma half-life of codeine and its metabolites is approximately 3 hours.5 CYP2D6 is highly polymorphic across populations, resulting in significant individual variation in the rate of morphine production.4
Dangerous
Highest riskThese 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.
Unsafe
AvoidThere is considerable risk of physical harm when taking these combinations, they should be avoided where possible.
Caution
Use cautionThese 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.
Tolerance
Tolerance timelines are rules of thumb, not exact schedules, and vary widely between individuals and use patterns.
Opioids (morphine, heroin, and other μ-opioid receptor agonists)
Harm Potential
Addiction & Dependence
Psychological
ModerateCodeine exhibits abuse potential similar to other opioid medicationscitation needed, though it is considered less reinforcing than stronger opioids like morphine or heroin. There is a tendency to underestimate its harm potential, particularly with codeine-promethazine cough syrup formulations where at least two deaths in the hip-hop community have been attributed to chronic use.
Physical
HighChronic use causes physical dependencecitation needed with potentially severe withdrawal symptoms including drug craving, runny nose, yawning, sweating, insomnia, weakness, stomach cramps, nausea, vomiting, diarrhea, muscle spasms, chills, irritability, and pain. Withdrawal can be as painful and long-lasting as heroin withdrawal, with symptom onset typically within 4-48 hours and duration of 4-5 days.
Toxicity
Respiratory depression is the primary mechanism of fatal overdose and can occur even at near-medical doses in susceptible individuals, particularly ultrarapid CYP2D6 metabolizers, young children, or when combined with other respiratory depressants.citation needed
Reduced intestinal motility and constipation are common with regular use; chronic opioid use may lead to obstructive bowel disease, particularly in patients with underlying intestinal motility disorders.citation needed
Cardiovascular effects including orthostatic hypotension and bradycardia may occur during use, with compromised ability to maintain blood pressure due to peripheral vasodilation.citation needed
Long-term use may cause reduced sexual desire in both sexes; women may experience absent or irregular menstruation. Opioids can suppress the hypothalamic-pituitary-gonadal axis over weeks to years, lowering sex-hormone secretion and contributing to reduced libido or menstrual irregularity.7
Chronic long-term use may contribute to apathy and memory loss; sedation, drowsinesscitation needed, and cognitive impairment occur during acute intoxication.
Seizure Risk
Seizures are listed as a rare adverse effect. Seizures have also been observed in neonates experiencing narcotic withdrawal from maternal codeine use during pregnancy.
History & Culture
Origins and Discovery
Codeine derives its name from the Greek word "kodeia," meaning "poppy head," reflecting its natural occurrence as an alkaloid in the opium poppy (Papaver somniferum). The compound comprises approximately 2% of raw opium, which has been used by humans for millennia. The poppy may have been…
Legality
International
1961 Convention: Schedule II.
1971 Convention: not internationally scheduled.
1988 Convention: not internationally scheduled.
By Country
References
Source Pages
Citations
- Codeine (PIM 140). Poisons Information Monograph (1996). https://www.inchem.org/documents/pims/pharm/codeine.htm1
- PsychonautWiki. psychonautwiki.org (n.d.). https://psychonautwiki.org/wiki/Codeine/Summary12
- TripSit Wiki. wiki.tripsit.me (n.d.). https://wiki.tripsit.me/wiki/Codeine1
- Clinical Pharmacogenetics Implementation Consortium Guidelines for Codeine Therapy in the Context of Cytochrome P450 2D6 Genotype. Clinical Pharmacology & Therapeutics (2012). https://pmc.ncbi.nlm.nih.gov/articles/PMC3289963/1234
- Codeine Sulfate Tablets: Prescribing Information. DailyMed / National Library of Medicine (2026). https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=5819bdf7-300e-45b8-8f3a-447b53656293123456789
- Codeine Sulfate Tablets — Prescribing Information. DailyMed (n.d.). https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=f317cd06-2851-4a52-86d3-6efde3a4c2431
- Opioids and endocrine dysfunction. (n.d.). https://pmc.ncbi.nlm.nih.gov/articles/PMC4590093/12
- Association Between Commonly Prescribed Opioids and Androgen Deficiency in Men. pmc.ncbi.nlm.nih.gov (n.d.). https://doi.org/10.1093/pm/pnw1821
- World Health Organization. (2023). WHO Model List of Essential Medicines – 23rd list, 2023. World Health Organization. https://www.who.int/publications/i/item/WHO-MHP-HPS-EML-2023.021
- World Health Organization. (2012). The Selection and Use of Essential Medicines: Report of the WHO Expert Committee, 2011 (WHO Technical Report Series 965). 965. https://iris.who.int/server/api/core/bitstreams/efcb2a17-8bc1-44dc-9b05-22c8f870fab2/content1
Further Reading
Article Status
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Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
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