| | Family Health | Teen Substance Abuse

Alcohol Metabolism: How Long Does It Stay in Your System?

Alcohol Elimination Basics

Alcohol (ethanol) is metabolized primarily in the liver via alcohol dehydrogenase (ADH) → acetaldehyde → aldehyde dehydrogenase (ALDH) → acetate. A small fraction (<10%) is excreted unchanged in breath, urine, sweat.

Average Rate

~0.015 g/dL per hour (one standard drink metabolized in ~1 hour for a 70 kg adult).

Standard drink: 14 g pure ethanol = 12 oz beer (5%), 5 oz wine (12%), 1.5 oz spirits (40%).
Half-gallon (1.9 L) of 40% spirits = ~60 standard drinks → ~60 hours to clear (not 6 hours as sometimes misstated).

Factors Influencing Metabolism

Detection Windows

Breath/Blood: Hours (until metabolized)
Urine (EtG/EtS metabolites): Up to 80 hours (heavy use up to 5 days)
Hair (EtG): Months (chronic use)
Saliva: ~12–24 hours

Health Risks of Chronic Use

Liver: Steatosis → steatohepatitis → cirrhosis → HCC
Cardiovascular: Hypertension, cardiomyopathy, arrhythmia, stroke
Neurologic: Cognitive decline, neuropathy, Wernicke-Korsakoff
Cancer: Oral, esophageal, liver, breast, colorectal
Mental health: Depression, anxiety, AUD

If concerned about your drinking, talk to a clinician—screening (AUDIT-C) and effective treatments (naltrexone, acamprosate, counseling) exist.

Teen Substance Abuse - Related Articles

Factor	Effect
Genetics (ADH/ALDH variants)	East Asian ALDH2*2 variant → acetaldehyde flush, slower clearance
Sex	Women: lower gastric ADH, higher body fat % → higher BAC per drink
Body weight/composition	Lower weight, higher fat % → higher BAC
Age	Older: ↓ liver volume, ↓ blood flow, ↑ comorbidities
Liver health	Cirrhosis, fatty liver → ↓ metabolic capacity
Food intake	Food (esp. protein/fat) ↓ gastric emptying → ↓ peak BAC, ↑ absorption duration
Medications	Some inhibit/induce ADH/CYP2E1 (e.g., isoniazid, disulfiram, metronidazole)