Tetrahydrocannabinol, the chemical in marijuana that makes people feel "high," can stay in the body for several days or even weeks.
Length of time the chemical stays in our body depends on these factors:
- how much body fat a person has
- how often they consume the drug
- how much someone smokes
- the sensitivity of the drug test
Drug tests can detect tetrahydrocannabinol, or THC, in urine, blood, and hair for many days after use, while saliva tests can only detect THC for a few hours. This is because of the way the body metabolizes THC.
Research from 2017 estimates a detection window for a single marijuana cigarette of about 3 days. The detection windows vary and depend on how often a person smokes.
For someone smoking marijuana for the first time, tests may detect it for about 3 days. In someone who smokes marijuana three or four times per week, the detection window is 5–7 days. For people who smoke marijuana once a day or more, tests may detect it in their system for 30 days or longer.
Detection windows varies in person according to the type of test a person taking:
- Urine tests can detect marijuana in the urine for approximately 3–30 days after use.
- Saliva tests can detect marijuana for approximately 24 hours after use. Some saliva tests have detected marijuana for up to 72 hours.
- Hair tests are the most sensitive tests, detecting THC for up to 90 days after use. However, these tests are testing the oil in skin that transfers to hair, and so they may occasionally show a false positive. A person who comes into contact with a THC user could, theoretically, test positive on a hair test.
- Blood tests can only detect THC for 3–4 hours.
Factors that influence detection
• Test sensitivity
More sensitive tests can detect lower doses of marijuana. Tests include blood, urine, hair, and saliva.
• THC dose
Marijuana drug tests look for THC, not marijuana. So the amount of THC that a person consumes is the significant factor.
The effects of THC are cumulative. This means that a person who smokes several times over several days has consumed a higher THC dose than someone who smokes once, and so they are more likely to test positive.
• Body fat
Since fat stores marijuana, people with higher body fat concentrations may metabolize marijuana more slowly than a person with less body fat.
• Body mass index (BMI) is one way to judge body fat.
However, since weight, and therefore BMI, increase with muscle mass, BMI is not a perfect measure of body fat.
• Sex
Typically, females have more body fat than males. This means that females may metabolize marijuana slightly more slowly.
• Hydration
Dehydration increases concentrations of THC in the body. While drinking lots of water is unlikely to affect a drug test significantly, severe dehydration might.
• Exercise
Exercise will not significantly change the rate at which the body metabolizes THC. Exercising before a drug test, however, might.
• Metabolism
For a drug test to be negative, the body must eliminate THC from the system, as well as metabolic chemicals that have links to THC. People with faster metabolisms typically eliminate THC more quickly than those with slower metabolisms
Quick fact on how marijuana affects your body
References
- https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.drugabuse.gov/publications/drugfacts/marijuana&ved=2ahUKEwj-wpHqtd_mAhXXfX0KHZjqALYQFjAHegQIDxAJ&usg=AOvVaw2ON1psCRDx4Typ9lOXliZ1
- https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.cdc.gov/marijuana/health-effects.html&ved=2ahUKEwj-wpHqtd_mAhXXfX0KHZjqALYQFjAPegQICBAB&usg=AOvVaw2PuxKYa_yYP19CRGMnltQT
Image References:
- https://files.nccih.nih.gov/s3fs-public/marijuana_GettyImages-116036237_square.jpg?j23EcE1mwn6vi_OpfWnTqCiEaWYyAZuh
- https://www.healthline.com/health/how-long-does-weed-stay-in-your-system
- https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.healthline.com/health/addiction/marijuana/effects-on-body&ved=2ahUKEwj-wpHqtd_mAhXXfX0KHZjqALYQFjAIegQIARAB&usg=AOvVaw3cxklgSKzj2aastHenWrSP
