Drug Test Detection Times refer to the “window” of detection for drugs of abuse. If a person is tested too soon or too long after use, drugs may not show up in human urine. Often someone will ask us, How long to drugs stay in the body? This short guide will help to answer that question. For the purposes of clarity, this is a reference for the detection of drugs of abuse found in human urine.
How long do drugs stay in your system? The length of time that the presence of drugs of abuse in the body can be detected is an important factor in drug screening. The chart below outlines approximate duration times. When interpreting the duration for the presence of drugs of abuse in the body, you must take into consideration variables including the body’s metabolism, the subjects physical condition, overall body fluid balance, state of hydration and frequency of usage.
Drug Detection Times in urine are expressed below in terms of lower and upper boundaries. The amount of time that a drug/metabolite remains detectable in urine can vary, depending on the following factors:
o Amount and Frequency of Use: Single, isolated, small doses are generally detectable at the lower boundary. Chronic and long-term use typically result in detection periods near or at the upper boundary.
o Metabolic Rate: Individuals with slower body metabolism are prone to longer drug detection periods.
o Body Mass: In general, human metabolism slows with increased body mass, resulting in longer drug detection periods. In addition, THC (the active ingredient in marijuana) and PCP are known to accumulate in fatty lipid tissue. Chronic users, physically inactive users, and individuals with a high percentage of body fat in relation to total body mass are prone to longer drug detection periods for THC and PCP.
o Age: In general, human metabolism slows with age, resulting in longer drug detection periods.
o Overall Health: In general, human metabolism slows during periods of deteriorating health, resulting in longer drug detection periods.
o Drug Tolerance: Users typically metabolize a drug faster once a tolerance to the drug is established.
o Urine pH: Urine pH can impact drug detection periods. Typically, highly acidic urine results in shorter drug detection periods.
o Note: In a small percentage of cases, users may test positive longer than times shown – most notably in cases of long-term chronic abuse, in individuals with significant body mass and/or body fat, and in individuals with health related issues resulting in abnormally slow body metabolism.
Drug Detection Times in Urine
Drug / Drug Group Time Range
o Alcohol 24 hours or less
o Amphetamines 1 to 4 days
o Barbiturates Short-acting: 1 to 3 days
Long-acting (Barbital, Phenobarbital): 1 to 3 weeks
o Benzodiazepines Short-term Therapeutic Use: 1 to 3 days
Long-term / Chronic Use: 1 to 3 weeks
o Cocaine 1 to 5 days
o LSD 1 to 2 days
o Marijuana (THC) Casual Use: 1 to 7 days
Long-Term / Chronic Use: 1 to 4 weeks Note: THC, the primary active ingredient in marijuana, is stored by the body in fatty lipid tissue. From there, it is slowly released into the bloodstream for up to several weeks – depending on the amount and frequency of use and the user’s level of physical activity. In chronic and physically inactive users, THC may accumulate in fatty tissues faster than it can be eliminated. This accumulation leads to longer detection periods for these individuals. Also, users with a high percentage of body fat in relation to total body mass are prone to longer drug detection periods for marijuana.
o MDMA (Ecstasy) 1 to 4 days
o Methadone 1 to 4 days
o Methamphetamines 1 to 4 days
o Opiates 1 to 5 days
o PCP (Phencyclidine) Casual Use: 1 to 7 days
Long-Term / Chronic Use: 1 to 4 weeks Note: PCP is stored by the body in fatty lipid tissue. From there, it is slowly released into the bloodstream for up to several weeks – depending on the amount and frequency of use and the user’s level of physical activity. In chronic and physically inactive users, PCP may accumulate in fatty tissues faster than it can be eliminated. This accumulation leads to longer detection periods for these individuals. Also, users with a high percentage of body fat in relation to total body mass are prone to longer drug detection periods for PCP.