1. Amphetamines – testing positive could indicate illegal use of stimulants like Adderall, Ritalin, as well as other prescribed stimulants, ephedrine, ecstasy, crystal meth, and STP are common street drugs that would should up. 1-4 days


  1. Barbiturates – these are rarely used anymore due to the discovery of benzodiazepines. Prescribed drugs would include amytal, Nembutal, secobarbital. You will rarely see any addict test positive for this. 2-3 days


  1. Cocaine –depending on the levels of detection and the time of the testing, you can easily hire a cocaine or crack addict who tested negative on a drug test. Cocaine only stays in your system for about 24 hours (maybe up to 48 hours if you’re a heavy user). Freebase cocaine (cocaine in its most purest form) will still be out of your system if you use on Friday night and are tested on Tuesday. 1-2 days


  1. Cannabinoids – Marijuana stays in your system the longest, so it’s the most likely to come up on a drug test. 4-60 days


  1. Methaqualone – you’ll rarely see anyone test positive to this. Quaaludes haven’t been produced for decades and they are virtually nonexistent on the streets because they are virtually nonexistent anywhere. The US stopped manufacturing Quaaludes in 1982. Someone who wanted to get a hold of these would be buying something from in underground lab. 3 days


  1. Opiates – Probably one of the most likely positives on a drug test, but there are numerous medical uses for opiates. Codeine, morphine, heroin, oxytocin, and hydrocodone would all fall into this category. 2-5 days


  1. Phencyclidine – aka PCP is unlikely to show up in a drug test. The recreational use of PCP has been on the decline for decades. Fewer than 3% of high school students in the 90s every reported using or trying PCP. It was mainly popular in the 60s and 70s. 1-8 days


  1. Benzodiazepines – Very likely to show up on a drug test in many individuals. With very extensive medical uses for various disorders, it is likely someone who tested positive would have a prescription somewhere down the line for it’s use. Drugs like Ambien, Xanax, Klonopin, Valium, Ativan, Lorazepam, and Restoril are all common benzodiazepines used to treat general anxiety disorder, insomnia, phobias, and panic disorder, and many many others. 2-8 days


  1. Methadone – used almost exclusively for heroin addiction. 1-7 days


  1. Propoxyphene – a specific type of opioid that wouldn’t show up in a standard opiate screen. It’s used as a local anesthetic and cough suppressant. It’s banned in the US, but was available as Darvon. May also be found in Darvocet. 4+ days


Note: Detection periods for all chemicals are approximations for urine analysis. Length of detection varies depending on frequency of use, dosage, concentration and individual metabolic differences.