How long is a drug detectable in the urine?

I get asked all the time about how long drug X is detectable in the urine of a person who consumed said drug (i.e. toxicology results interpretation is part of the day job).

                                                      Chemical structures of THC-carboxylic acid metabolite and PCP


Drug detection windows in urine are variable and approximate and ultimately depend on a myriad of factors including the nature of the drug consumed, the route of administration of drug, the individual's metabolism, the dosage of drug consumed, the dosage form of the drug consumed, and the hydration state of the individual.

So, here's a handy list for some routine drugs:

Analyte	Time Range
6-acetylmorphine	12 - 24 hours
7-aminoclonazepam	1 - 10 days
Acetaminophen	1 - 2 days
Alprazolam and alphahydroxyalprazolam	1 - 4 days
Amobarbital	1 - 5 days
Amphetamine	1 - 5 days
Benzoylecgonine	1 - 4 days
Buprenorpine and norbuprenorphine	1 - 10 days
Butabarbital	1 - 5 days
Butalbital	1 - 5 days
Carisoprodol	1 - 2 days
Codeine	1 - 4 days
Ethanol	1 - 24 hours
Ethyl Glucuronide	1 - 3 days
Fentanyl and norfentanyl	1 - 4 days
Gabapentin	1 - 4 days
Hydrocodone	1 - 4 days
Hydromorphone	1 - 4 days
Lorazepam	1 - 4 days
MDMA	1 - 5 days
Meprobamate	1 - 4 days
Methadone and EDDP	1 - 10 days
Methamphetamine	1 - 5 days
Morphine	1 - 4 days
Nordiazepam	1 - 10 days
Oxazepam	1 - 10 days
Oxycodone	1 - 4 days
Oxymorphone	1 - 4 days
PCP	1 - 8 days
Pentobarbital	1 - 3 days
Phenobarbital	1  - 30 days
Phentermine	1 - 4 days
Pregabalin	1 - 4 days
Propoxyphene and norpropoxyphene	1 - 5 days
Secobarbital	1 - 3 days
Tapentadol	1 - 2 days
Temazepam	1 - 10 days
THC-COOH (frequent user)	1- 30 days
THC-COOH (occasional user)	1 - 4 days
Tramadol and nortramadol	1 - 4 days

It is important to remember that the urine matrix is a waste/excretory product. Drugs or drug metabolites detected in the urine are not exerting a pharmacological effect on the body. Also, there is no correlation between an ingested dose and the resulting urine concentration of drug/metabolite. If these are a concern, then blood analysis should be undertaken, but it should be noted that detection of drug or metabolite in the blood matrix is typically considerably shorter than the urine window of detection.

Cheers,

ForensicToxGuy