Delta 9

THC stands for delta-9-tetrahydrocannabinol or Δ-9-tetrahydrocannabinol (Δ-9-THC). It is a cannabinoid molecule in marijuana (cannabis) that's long been recognized as the main psychoactive ingredient—that is, the substance that causes people who use marijuana to feel high.

How THC Works

THC works by attaching to the body's cannabinoid receptors, which are found throughout the brain and nervous system. THC can be detected in the body much longer than most other drug compounds (up to 20 hours after ingestion), although the psychoactive effects only last for a few hours.

THC is also stored in body fat and organs for three to four weeks. Hair follicle testing may identify THC after even longer periods of time, around 90 days. Urine testing is often used but has been found to be an unreliable method of detection.