Cocaine itself has a very short half-life (30–90 minutes), but its primary metabolite benzoylecgonine has a half-life of 5–8 hours and is detectable in urine for 2–4 days after occasional use and up to 14 days after heavy or prolonged use. When cocaine is consumed with alcohol, the liver produces cocaethylene, which extends detection windows and significantly increases health risks.
Urine tests detect benzoylecgonine, not cocaine itself. The standard cutoff is 300 ng/mL for screening and 150 ng/mL for confirmation. Because benzoylecgonine has a much longer half-life than cocaine, urine detection extends well beyond the period of psychoactive effects.
Cocaethylene formation (when cocaine is used with alcohol) extends detection times by 20–30% and carries significantly higher cardiovascular toxicity. This metabolite is uniquely produced by the combination and is not formed from either substance alone.
Blood tests can detect cocaine for 12–48 hours and are primarily used in emergency medical settings and accident investigations. Saliva testing has a 1–2 day window and is used in some workplace and roadside screening programs.
Benzoylecgonine Clearance
Clearance Time ≈ 5 × Half-life (5-8h) = 25-40 hours for single use
Five half-lives are needed to eliminate >96% of a substance. Benzoylecgonine's 5–8 hour half-life means most clearance occurs within 25–40 hours for occasional use, but chronic use causes accumulation.
Occasional user, single use, 75kg body weight.
Result: For occasional use, urine tests are the primary concern with a 2–4 day detection window. Blood clears within 48 hours. If used with alcohol, add 20–30% to all detection estimates.
Occasional use: 2–4 days. Regular use: 5–7 days. Heavy chronic use: 7–14 days. The metabolite benzoylecgonine is what tests detect.
Yes. Concurrent use produces cocaethylene, which has a longer half-life than benzoylecgonine and extends detection by approximately 20–30%.
Snorted: 15–30 minutes. Smoked (crack): 5–10 minutes. This short duration often leads to repeated use, which significantly extends detection times.