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How Long Do Drugs Show Up in Your System?


Like food, illegal substances and prescription medications take time for your body to digest. While the effects of a drug might last your body just a few short hours, the traces of that drug can linger for double that. Sometimes drugs can linger in your system for weeks.

The detectability of a drug in your system will depend on a variety of factors, including:

  • The type of drug you ingest
  • Your health
  • Metabolism
  • Gender, height, and weight
  • How much of the drug you took
  • How often you use that drug

Your body’s organs are all responsible for metabolizing and destroying traces of a drug in your system. Some drugs are detectable in blood, while others only show in urine, saliva, or hair samples.

Crimes in which Drug Tests are Used

If you are suspected of a crime, the police officer might test for traces of drugs, including prescription medications. They may do this if they suspect you are under the influence and cause a motor vehicle accident too.

Drug testing has become increasingly common by law enforcement.  With drug screenings more prevalent, the chances are that you will be requested to take a screening of some sort after an accident or when you are arrested for a crime.

The Most Common Types of Drug Tests

Law enforcement typically uses the breathalyzer when they assume that you are under the influence of alcohol. However, when they are testing for drugs, they will use one of the following major test types:

  • Urine: Urinalysis testing is quick, accurate, and affordable, which is why it is the more popular option for police officers.
  • Blood: Blood testing might be ordered along with a urine test or if officers suspect you have taken a drug that may metabolize too quickly for urine detection. Blood testing takes longer than urine, but it is more effective and can determine intoxication levels.
  • Saliva: Saliva can hold traces of chemicals and hormones from medications and drugs you ingest. It was once a popular method for drug screenings, but with the advanced technology for blood and urine, it is not as widely used by law enforcement. Drugs are only detectable in saliva from a few hours to a few days after taking them.
  • Hair: Hair is one of the only tests that can detect drug use for extended periods of time, and traces of drugs can be detected months after the fact. Hair analysis will take much longer and is costlier; therefore, law enforcement will only use hair testing when urinalysis and blood screenings are not viable.

How Long Do Drugs Remain Detectable?

The type of drug you take will play a role in how long that drug is detectable. Here are some of the common types of drugs tested for by law enforcement and how long they can remain in your system:

  • Amphetamines – Stimulants that have a high risk for abuse and dependency. The dose itself might only last 2-4 hours, but the drug remains in your urine for 48 hours and hair for up to 90 days.
  • Barbiturates – Suppresses the central nervous system and creates a sedative-like effect. Long-acting versions can stay in the body for 140 hours, while short-acting versions disappear within 40 hours. Short-acting versions are detectable in the urine by up to five days, while long-acting can remain detectable for up to three weeks.
  • Benzodiazepines – Used to control anxiety and sedate the body. These include Valium, Xanax, and Ativan, which are all highly addictive and easily abused. Xanax and Valium might show in the urine up to seven days after your last pill, but most benzos last two to five days in the urine.
  • Cocaine – Cocaine is highly addictive and creates a “rush” within the body. After 15 minutes of taking cocaine, your blood reaches peak levels and starts to decline rapidly. Cocaine is only detected in the blood for 12 hours after ingestion, but if you take it regularly, it may show for up to two weeks in your urine. Hair can reveal cocaine use for three or more months.
  • Heroin – Heroin is a narcotic that is highly addictive and sedates almost instantly. The body can eliminate traces of heroin quickly. It might only be detectable for up to 48 hours in the urine.

Other Drugs and How Long They Remain Detectable

  • MDMA (Ecstasy) – In urine, MDMA can appear anywhere from one to five days – depending on how frequently you take the drug.
  • LSD – LCD, also known as acid, can be detectable within a few hours of taking it and last up to five days by urine. Hair analysis may show more extended usage.
  • Ketamine – Ketamine or “Special K,” lasts in the body for two to four days and can be detected by hair analysis for much longer.
  • Marijuana – Marijuana takes effect within three to eight minutes of ingestion, but the active ingredients of marijuana remain in your system for up to four weeks if you are a long-term user. Chronic users can test positive in a urinalysis for up to 30 days past their last use.
  • Methamphetamines – Also known as meth and crack, these stimulants are robust and take an instant effect. Byproducts peak within 12 hours of consuming them, but meth can remain detectable in your urine for two to four days past ingestion, and traces are found in the hair for up to 90 days past the last dose.

Speak with a Defense Attorney Immediately

If you have been arrested for a crime, and law enforcement is using a positive drug screening as evidence, it is imperative that you speak with a criminal defense attorney. Contact the Shlosman Law Firm today to discuss your case and explore your options.

Request a free case evaluation now at 504-826-9427 or request more information online.