Last updated : July 14, 2025
All drugs are not created equal. While that is a seemingly obvious statement, the differences also extend to how long after the last use each drug is detectable by modern testing methods. Urine, oral fluids, and hair are commonly used as test specimens to screen for common drugs such as alcohol, marijuana, opiates/opioids, cocaine, amphetamines, methamphetamines, methaqualones, MDMA (Ecstasy), LSD, and PCP.
Several factors come into play during the drug screening process. Each drug interacts differently with the human body, so the detection windows vary greatly depending on the user’s body type, the frequency of use, and potency of the drug. The active ingredient in marijuana is stored in fat cells, so it remains in the system much longer than a drug like cocaine, which does not build up regardless of frequency used.
How Long do Common Drugs Stay in Your System?
A person’s physiology plays a large role in the length of time a drug stays in their system. Most people understand that height, weight, and body fat can impact the length of time it takes the body to process illicit drugs. However, additional factors that may impact the amount of time a drug stays in your system include stress, level of exercise, and current overall health. According to the National Institutes of Health, “Alcohol and drugs vary substantially in their windows of detection, largely owing to their degree of fat solubility. For example, THC and other highly fat-soluble compounds have a very long half-life of elimination and can be detected in urine up to weeks after last use among heavy users).”
Frequency and the sheer quantity of drugs used plays a huge role in the amount of time certain drugs remain in your system. The length of time drugs are used consistently, and the potency of the drugs also factor into how long they remain detectable by urinalysis and oral fluids testing. Keep in mind that all of these factors mean there is some variance in time-frames, but adhering to the guidelines will render you the best chance to accurately detect the presence of drugs in the system.
Common drugs and their testing window
Alcohol (a.k.a. booze, hooch, beer, wine, liquor) takes the body approximately 1 hour per drink to process. The speed with which alcohol is consumed and the amount consumed may result in a positive test up to 12 hours after heavy consumption.
Marijuana (a.k.a. pot, weed, grass, herb, reefer, bud) lasts in the body system approximately 2-5 days for one-time use. Because the active ingredient in marijuana (THC) is stored in fat, heavy users may still test positive 4-6 weeks after their last use.
Opioids (a.k.a. heroin, opium, morphine, hydrocodone, oxycodone, fentanyl, methadone) last approximately 1-2 days, though some variations may show up as long as 7 days after last use.
Cocaine (a.k.a. coke, crack, candy, rock, snow) also has a limited 1-2 day testing window.
Amphetamines (a.k.a. Black Beauties, Dexedrine, biphetamine) only stay in the system for approximately 1-2 days
Methamphetamines (a.k.a. speed, ice, crank, glass, Desoxyn, crystal) stays in the system for 2-4 days.
LSD (a.k.a. acid, Microdot, blotter, Yellow Sunshine) may last only a few hours, though factors discussed above may extend the window to up to 5 days.
MDMA (Ecstasy) remains in the system from 1-5 days.
Methaqualone (a.k.a quaaludes, ludes) has a longer testing window as it stays in the system for 10-15 days.
PCP (Angel Dust, Love Boat, Boat, Hog) has a testing window from 1-8 days.
Why does drug testing benefit the workplace?
All drug users do not fit the negative stereotypes on the surface. Studies indicate many illicit drug users are employed either part-time or full-time. Employees who use drugs are more likely than non-users to be late or miss work, change jobs frequently, be less productive, and cause potential accidents which result in worker’s compensation claims.
Drug-free workplace programs result in improvements in morale and productivity, while absenteeism, accidents, downtime, turnover, and theft generally decrease over time after successful implementation of drug-free workplace programs.
Over time, employers report healthier employees and family members which reduce healthcare costs. Some employers with drug-free workplace programs qualify for incentives they may then pass on to employees, such as decreased disability and workers’ compensation insurance cost.
