Coca

Traditional and historical use

Indigenous peoples of the Andes have cultivated and consumed coca for millennia, with archaeological evidence placing use at least 8,000 years before present.^[3] The two primary cultivated species — E. coca and E. novogranatense — were selected for their tropane alkaloid content before formal domestication of either species.^[3] Traditional preparation involves chewing fresh leaves with an alkaline additive — calcium hydroxide, sodium bicarbonate, or llipta (plant ash) — to raise buccal pH and facilitate cocaine absorption.^[9]

Documented traditional applications include stamina enhancement during physical labor, hunger and fatigue suppression, altitude sickness mitigation, mild analgesia, and ceremonial use.^[9][3] These accounts derive from ethnographic and anthropological documentation rather than controlled clinical studies.

Western discovery and pharmaceutical development

Spanish chroniclers documented coca use in the 16th century, though knowledge of its stimulant properties spread slowly in Europe. Albert Niemann first isolated cocaine from coca leaves in 1860 at the University of Göttingen, noting the anesthetic effect on his tongue in his dissertation.^[4] Richard Willstätter established cocaine's correct molecular structure in 1898.citation needed

The isolation catalyzed rapid pharmaceutical adoption. Carl Koller demonstrated cocaine as a topical ophthalmic anesthetic in 1884, revolutionizing eye surgery.^[4] William Halsted pioneered nerve block anesthesia using the compound but developed dependence in the process. Commercial applications followed: Coca-Cola launched in 1886 using coca extract, though the product was decocainized by 1903.^[9]

Modern era

The Harrison Narcotics Tax Act (1914) restricted non-medical cocaine distribution in the United States. The 1961 UN Single Convention on Narcotic Drugs placed both coca leaf and cocaine on Schedule I, and the 1988 Convention reinforced controls on cocaine precursors. Bolivia temporarily withdrew from the 1961 Convention in 2012 and reacceded in 2013 with an explicit reservation permitting traditional coca leaf chewing.citation needed

In October 2025, the WHO Expert Committee on Drug Dependence completed a comprehensive critical review of coca leaf and recommended maintaining Schedule I classification, while acknowledging the low public health risk of traditional consumption and the cultural significance of coca to indigenous peoples.^[5]

Erythroxylum coca Lam. belongs to the family Erythroxylaceae, a small family of tropical and subtropical shrubs and trees. The genus name derives from Greek erythros (red) and xylon (wood), referring to the reddish heartwood characteristic of the group. Two primary cultivated species are recognized: E. coca (Huánuco coca) and E. novogranatense (Colombian coca), each with recognized varieties that differ in alkaloid content and geographic distribution.

Coca is native to the eastern slopes of the Andes in Peru and Bolivia, thriving in warm, humid montane forest between roughly 500 and 2,000 meters elevation. Bolivia, Peru, and Colombia account for virtually all current cultivation. The plant is not known to persist in the wild independent of human cultivation in any significant population.

The shrub grows 1–3 meters tall with slender, oval leaves 4–8 cm long. Each leaf bears two faint longitudinal lines parallel to the midrib — a diagnostic feature distinguishing Erythroxylum from superficially similar shrubs. Small yellowish-white flowers produce red drupes approximately 1 cm in length.

Leaves are harvested by hand two to four times per year, sun-dried, and either consumed directly (chewing, tea infusion) or processed into refined alkaloid preparations. Drying method influences alkaloid retention: traditional sun-drying preserves the full alkaloid profile, while industrial extraction targets cocaine specifically. Potency varies across cultivars, harvest batches, altitude, and seasonal conditions.

Cocaine is the dominant pharmacologically active alkaloid in coca, present at 0.2–1.0% of leaf dry weight. It acts as a non-selective monoamine reuptake inhibitor — blocking the dopamine, norepinephrine, and serotonin transporters — with additional voltage-gated sodium channel blockade that produces local anesthetic effects.^[1][2] Cocaine content varies across cultivars, growing conditions, altitude, and harvest timing, with E. coca var. coca typically yielding the highest concentrations.

Unlike cannabis or kratom, coca has no well-characterized entourage effect in which minor alkaloids meaningfully modulate the dominant alkaloid's activity. Traditional users sometimes attribute a qualitative difference between whole-leaf coca and purified cocaine to the full alkaloid matrix, but this has not been demonstrated in any controlled study. The pharmacological character of coca preparations is shaped almost entirely by cocaine itself.

Several minor tropane and non-tropane alkaloids are present in the leaf. Cinnamoylcocaine and its isomers are structurally related to cocaine but pharmacologically weaker. Truxillines (alpha- and beta-truxilline) are dimeric cocaine derivatives present in trace amounts. Hygrine, a non-tropane pyrrolidine alkaloid, is present at variable concentrations and lacks significant central nervous system activity. The relative contribution of these minor alkaloids to the overall pharmacological profile of whole-leaf preparations remains unknown.

Alkaloid concentrations vary across the two cultivated species and their varieties. E. novogranatense tends toward lower cocaine content with a proportionally higher fraction of minor alkaloids compared to E. coca. Harvest season, soil conditions, and drying method all influence the final alkaloid profile of commercially available leaf material.

Where it acts

Cocaine's principal psychoactive effects arise from blockade of the DAT in the mesolimbic pathway — the projection from the ventral tegmental area to the nucleus accumbens.^[1] The resulting surge of synaptic dopamine produces euphoria and behavioral reinforcement. A proposed mechanistic refinement suggests cocaine may reverse transporter direction, actively pumping dopamine into the synapse rather than simply blocking reuptake — potentially explaining why cocaine produces greater euphoria than other dopamine reuptake inhibitors of comparable binding strength.^[1]

Concurrent NET blockade drives cardiovascular activation and heightened arousal. Serotonin transporter blockade, the weakest of the three, contributes to mood elevation. Sodium channel blockade underlies the local anesthetic effect and the arrhythmogenic potential that contributes to cocaine-associated sudden cardiac death.^[2]

What it changes

With repeated cocaine exposure, glutamatergic and opioidergic plasticity at nucleus accumbens synapses contributes to compulsive use and relapse vulnerability.^[3] Tolerance to euphoriant effects develops rapidly, while sensitization — not tolerance — occurs for psychomotor activation and psychosis risk. This explains why chronic users chase a diminishing high while facing escalating psychiatric danger.

Cocaine induces its own hepatic CYP metabolism with chronic use,^[10] increasing production of norcocaine — an active metabolite with greater toxicity than the parent compound.^[11]

Per-preparation dose tiers, timelines, and bioavailability data are in the Dose · by preparation card on this page.

Cardiovascular complications represent the most clinically significant toxicity across all preparations.^[6][2][16] Frequent cocaine users face a 7-fold higher risk of myocardial infarction. Mechanisms include coronary artery vasospasm, accelerated atherosclerosis, thrombus formation, and QT prolongation via sodium channel blockade. Arrhythmias — including ventricular fibrillation and sudden cardiac death — are mediated by sodium channel blockade and catecholamine surge. Chronic use produces dilated cardiomyopathy, myocarditis, and left ventricular hypertrophy.

Norcocaine, the CYP3A4-generated metabolite, is hepatotoxic. Documented pathology includes perivenular necrosis and microvesicular fatty change.^[17] Multi-organ failure involving rhabdomyolysis, acute kidney injury, and hepatic ischemia has been documented as cocaine-induced C-KLM syndrome.^[18]

Smoked cocaine carries preparation-specific pulmonary risk. "Crack lung" syndrome presents as acute respiratory distress with fever, hemoptysis, and diffuse alveolar hemorrhage within 48 hours of inhalation.^[14] Both ischemic and hemorrhagic stroke are documented; cocaine is a recognized independent stroke risk factor. Reversible cerebral vasoconstriction syndrome has been reported even following coca leaf tea at high altitude.^[19]

Contaminant and adulterant risk: Levamisole, a veterinary anthelmintic, contaminates an estimated 69–80% of illicit cocaine in the United States.^[7][20] Clinical consequences include agranulocytosis with life-threatening infections, ANCA-associated vasculitis, multifocal leukoencephalopathy, and acquired protein S deficiency. Additional adulterants include local anesthetics (procaine, benzocaine, lidocaine) and, increasingly, fentanyl — which introduces opioid overdose risk toxicologically distinct from cocaine effects.

Coca leaf products sold in Andean countries carry lower adulterant risk than illicit refined cocaine, but no ISO/IEC-accredited third-party testing programs for commercial coca leaf products have been identified.citation needed

Sensitization rather than tolerance occurs for psychosis risk — repeated exposure progressively lowers the threshold for psychotic symptoms. Anxiety, paranoia, panic reactions, and agitation occur dose-dependently across all preparations. Grandiosity, impaired judgment, and compulsive redosing are characteristic at higher doses, particularly with smoked and intravenous preparations.

Dependence is primarily psychological, driven by mesolimbic dopamine reinforcement. Physical dependence is present but less prominent than with opioids or alcohol. Withdrawal follows a three-phase pattern^[22]:

• Phase 1 — Crash (hours to 4 days): dysphoria, fatigue, hypersomnia with REM rebound effect, appetite enhancement, temporarily reduced craving.
• Phase 2 — Withdrawal (1–10 weeks): anhedonia, anxiety, sleep disturbance, intense cue-triggered cravings; highest relapse risk period.
• Phase 3 — Extinction (months to years): Gradual normalization; intermittent cue-triggered cravings persist.^[22]

Beta-adrenergic blockers: Contraindicated. Cocaine's alpha-adrenergic effects become unopposed when beta receptors are blocked, producing severe hypertension and coronary vasospasm.

MAO inhibitors: Theoretical risk of hypertensive crisis and serotonin syndrome via amplified monoamine activity. safety citation needed

CYP3A4 inhibitors (ketoconazole, clarithromycin, ritonavir): May increase parent cocaine plasma levels by reducing clearance while decreasing norcocaine formation.^[11] safety citation needed

Tricyclic antidepressants: Additive cardiovascular toxicity via combined sodium channel blockade and norepinephrine reuptake inhibitor. safety citation needed

Contraindications

Coca leaf and cocaine are controlled under international treaty and domestic legislation in virtually all jurisdictions. The 1961 UN Single Convention on Narcotic Drugs places both coca leaf and cocaine on Schedule I — unlike some psychoactive plants where only the isolated alkaloid is scheduled, coca leaf itself is explicitly controlled alongside its primary alkaloid. Bolivia and Peru maintain legal frameworks permitting traditional coca leaf consumption, while refined cocaine is universally prohibited outside narrow medical applications. In the United States, cocaine hydrochloride retains limited medical approval as a topical nasal anesthetic.^[27]

Treaty and detection considerations

Bolivia's 2013 reservation represents the only formal treaty-level exception for traditional coca leaf use. The dual scheduling of both plant material and isolated alkaloid under the 1961 Convention is unusual among psychoactive plants — psilocybin mushrooms, for example, escape explicit plant-level scheduling in many jurisdictions while the alkaloid itself is controlled. The 2025 WHO Expert Committee critical review recommended maintaining this classification while acknowledging the low public health risk of traditional consumption.^[5]

Coca leaf chewing and tea consumption produce positive immunoassay urine drug tests for benzoylecgonine, cocaine's primary urinary metabolite. Standard workplace drug tests (100–300 ng/mL cutoff) detect metabolites for approximately 2–4 days after last use in most individuals. With sensitive assays using a 5 ng/mL cutoff, detection windows extend to 17–22 days.^[30][31]