Whether it be for research or recreation, you may have wondered at some point how long certain illicit drugs can stay in your system. Lucky for you, we’ve done our homework and figured out how long traces of the most popular illegal drugs remain detectable inside you.

Cannabis

Although cannabis is one of the least harmful of all illegally abused drugs, it tends to stay in the system the longest. THC is the active ingredient in marijuana, but when it is metabolized and broken down in the liver, it creates THC-COOH, which stays in our system for a very long time.

Exactly how long cannabis will stay in your system depends on many factors, such as how often you smoke and how much marijuana you consume. However, these are the average rates:

Urine: Seven to 30 days

Blood: Two weeks

Hair: Up to 90 days

Cocaine

Cocaine is a powerful stimulant drug and one of the most popular illegal street drugs in America. The drug induces feelings of extreme happiness and energy combined with mental alertness and hypersensitivity. However, cocaine abuse can lead to serious health problems such as malnourishment and increases one's risk for developing Parkinson's. Despite its dangers, cocaine actually stays in your system for a relatively short amount of time.

Urine: 3 to 4 days

Blood: 1 to 2 days

Hair: Up to 90 days

Heroin

Heroin is an opioid drug, and according to the National Survey on Drug Use and Health, in 2012 about 669,000 Americans reported using heroin in the past year. Heroin is highly addictive and can be injected, smoked or sniffed. Once again, however, it leaves your system relatively fast.

Urine: 3 to 4 Days

Blood: 12 Hours

Hair: Up to 90 days

LSD

LSD (D-lysergic acid diethylamide), also known as acid, is a hallucinogenic drug that can alter users' perception. A person using LSD may feel relaxed and more sociable but if they go on a “bad trip” users can quickly become frightened and panicky. LSD is also not known to stay in one's system for very long.

Urine: 1 to 3 days

Blood: 2 to 3 hours

Hair: Up to 3 days

MDMA (ecstasy)

MDMA is a synthetic psychoactive drug that gives users a feeling of emotional warmth, general sense of well being, and decreased anxiety. It is usually taken in the form of a tablet, and is very popular among ravers and the nightclub scene. These are the average times that MDMA may stay in a user’s system.

Urine: 3 to 4 days

Blood: 1 to 2 hours

Hair: Up to 90 days

Methamphetamine (Crystal Meth)

Methamphetamine is synthetically similar to amphetamine, but unlike its perscription cousin, is an illegal street drug. When taken, crystal meth can increase motivation, confidence, and give a euphoric rush. However, meth abuse is associated with severe health effects such as extreme weight loss, severe dental problems (“meth mouth”), and skin sores caused by scratching. Once again, crystal meth is also quite quick to leave a user’s system.

Urine: 3 to 6 days

Blood: 24 to 72 hours

Hair: Up to 90 days