How long can drugs be detected in the body with a drug test?

Many variables may affect the amount of time that a drug remains detectable in the urine or other biological samples, including a drug’s half-life, the subject’s state of hydration and fluid balance, frequency of use, route of administration, cut-off concentration used by the testing lab to detect the drug, and many other variables. Each person and circumstance is different, and the best way to avoid detection of an abusable drug is to not use the drug.

Drugs detection in the body

General guidelines are available for detection times. Many drugs stay in the system from 2 to 4 days, although chronic use of marijuana can stay in the system for 3 to 4 weeks or even longer after the last use. Drugs with a long half-life, such as diazepam, may also stay in the system for a prolonged period of time. Drugs can be detected in hair samples up to six months, although urine samples are used for most workplace drug screening tests. Examples of drugs that can be detected in hair-testing include alcohol, marijuana, cocaine, and amphetamines.

DRUG CLASS STREET NAME PRESCRIPTION BRAND NAME EXAMPLES DETECTION TIME IN URINE Amphetamine Stimulant speed Dexedrine, Benzedrine Up to 2 days Barbiturates depressants / sedatives / hypnotics downers, barbs, reds Amytal, Fiorinal, Nembutal, Donna short-acting:  2 days
long-acting: 1-3 weeks
(based on half-life) Benzodiazepines depressants / sedatives / hypnotics bennies Valium, Ativan, Xanax, Serax therapeutic dose: 3 days
chronic use: 4-6 weeks or longer Cocaine (Benzoyl ecgonine metabolite) Stimulant coke, crack, rock cocaine N/A Up to 4 days Codeine Analgesic / Opiate N/A N/A 2 days Ethyl alcohol, Ethanol depressants / sedatives / hypnotics alcohol, liquor, beer, wine booze N/A urine: 2 to 12 hours
serum/plasma: 1 to 12 hours Heroin Analgesic / Opiate smack, tar, chasing the tiger N/A 2 days Marijuana, Can-
nabinoids Hallucinogen pot, dope, weed, hash, hemp Marinol, Cesamet Single use: 2 to 7 days
Prolonged, chronic use: 1 to 2 months or longer Methadone Analgesic / Opiate fizzies Dolophine 3 days Methamphetamine Stimulant speed, ice, crystal, crank Desoxyn, Methedrine Up to 2 days Methaqualone depressants / sedatives / hypnotics ludes, disco bisquits, 714, lemmons Quaalude (off U.S. market) Up to 14 days MDMA (Methylenedioxy-
methamphetamine) Stimulant ecstacy, XTC, ADAM, lover’s speed N/A Up to 2 days Morphine Analgesic / Opiate N/A Duramorph, Roxanol 2 days Phencyclidine Hallucinogen PCP, angel dust N/A 8-14 days, but up to 30 days in chronic users Propoxyphene Analgesic / Opiate N/A Darvocet, Darvon (all form of propoxyphene withdrawn from US market in November 2010) 6 hours to 2 days

*Note: This table should be used as a general guideline only. Many variables may affect the amount of time that a drug remains detectable in the urine or other biological samples, including a drug’s half-life, the subject’s state of hydration and fluid balance, frequency of use, route of administration, cut-off concentration used by the testing lab to detect the drug, or other variables.