The short answer

Cannabis metabolites are the breakdown products your body creates after THC or CBD reaches the bloodstream. The one that matters most on a drug screen, THC-COOH (11-nor-9-carboxy-THC), is not psychoactive. It lingers because THC is fat-soluble and gets stored in adipose tissue, then released back into circulation in small amounts. A person who uses once can test positive in urine for about three days. A daily heavy user can test positive for up to a month.

How THC gets processed

Inhaled THC moves from the lungs into the blood and reaches the liver fast. Edible THC takes a detour through the gut and liver before it hits systemic circulation, which is why edibles feel different and last longer. In the liver, enzymes CYP2C9 and CYP3A4 convert delta-9-THC into 11-hydroxy-THC, a compound that is also psychoactive. From there the body oxidizes it into THC-COOH, which has no intoxicating effect. THC-COOH then gets tagged with glucuronic acid and leaves through urine and bile.

The metabolites that show up on tests

  • THC-COOH: the main urine screen target, inactive, detectable for days to weeks
  • 11-OH-THC: active, appears at higher levels after edibles because of first-pass metabolism
  • THC-glucuronide: the water-soluble form the kidneys can excrete
  • CBD metabolites such as 7-COOH-CBD: different pathway, usually not the target of a THC immunoassay

Detection windows by sample type

  • Urine: roughly 1 to 3 days after a single use, up to 30 days with chronic heavy use
  • Blood: THC itself clears within hours, THC-COOH within a few days
  • Oral fluid: about 24 to 48 hours, longer with frequent use
  • Hair: up to 90 days, since metabolites get trapped in the follicle as it grows

A positive test does not mean someone is high

THC-COOH has no psychoactive effect. Its presence only shows that THC entered the body at some point in the recent past. Blood THC levels, and ideally an officer's observations, are what speak to active impairment. That distinction drives most of the argument over workplace screening and roadside testing.

Why the convenient formats change the numbers

Vape carts, gummies, and pre-rolls all deliver THC, but they do not produce the same metabolite profile. A distillate vape sends a large THC dose straight to the lungs with no first-pass conversion, so THC-COOH is the dominant marker. A high-dose edible produces a bigger 11-OH-THC spike and a longer window of detection. Concentrates raise the amount of THC per session, and a heavier input means a longer time before the body clears the last of it. Convenience makes dosing easier and more repeatable, which usually means more frequent exposure over time. That is the part people miss when they assume a vape pen leaves the system faster than flower.

What actually changes clearance

  • Frequency and dose: the biggest factor by far
  • Body fat percentage: more fat means more storage and a longer release tail
  • Route of use: oral use tends to stay detectable longer than a single inhalation
  • Liver enzyme activity, age, and medications that inhibit CYP2C9
  • Hydration: drinking water dilutes urine but does not pull THC out of fat

CBD and synthetic cannabinoids

CBD breaks down into different compounds, and most THC immunoassays are not built to catch them. Some early assays do cross-react at high CBD doses, which is why a confirmatory GC-MS or LC-MS test matters. Synthetic cannabinoids are unrelated molecules with their own metabolites, so a standard THC screen will not flag them unless the lab orders a specific panel.

The practical takeaway

If you care about a test result, route and dose matter as much as the product label. Metabolites hang around on their own schedule, and no drink, supplement, or detox kit reliably changes that. A lab test tells you about past exposure. It does not tell you whether someone is impaired right now.