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.

DRUGCLASSSTREET NAMEPRESCRIPTION BRAND NAME EXAMPLESDETECTION TIME IN URINE
AmphetamineStimulantspeedDexedrine, BenzedrineUp to 2 days
Barbituratesdepressants / sedatives / hypnoticsdowners, barbs, redsAmytal, Fiorinal, Nembutal, Donnashort-acting:  2 days
long-acting: 1-3 weeks
(based on half-life)
Benzodiazepinesdepressants / sedatives / hypnoticsbenniesValium, Ativan, Xanax, Seraxtherapeutic dose: 3 days
chronic use: 4-6 weeks or longer
Cocaine (Benzoyl ecgonine metabolite)Stimulantcoke, crack, rock cocaineN/AUp to 4 days
CodeineAnalgesic / OpiateN/AN/A2 days
Ethyl alcohol, Ethanoldepressants / sedatives / hypnoticsalcohol, liquor, beer, wine boozeN/Aurine: 2 to 12 hours
serum/plasma: 1 to 12 hours
HeroinAnalgesic / Opiatesmack, tar, chasing the tigerN/A2 days
Marijuana, Can-
nabinoids
Hallucinogenpot, dope, weed, hash, hempMarinol, CesametSingle use: 2 to 7 days
Prolonged, chronic use: 1 to 2 months or longer
MethadoneAnalgesic / OpiatefizziesDolophine3 days
MethamphetamineStimulantspeed, ice, crystal, crankDesoxyn, MethedrineUp to 2 days
Methaqualonedepressants / sedatives / hypnoticsludes, disco bisquits, 714, lemmonsQuaalude (off U.S. market)Up to 14 days
MDMA (Methylenedioxy-
methamphetamine)
Stimulantecstacy, XTC, ADAM, lover’s speedN/AUp to 2 days
MorphineAnalgesic / OpiateN/ADuramorph, Roxanol2 days
PhencyclidineHallucinogenPCP, angel dustN/A8-14 days, but up to 30 days in chronic users
PropoxypheneAnalgesic / OpiateN/ADarvocet, 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.

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