How Long Does THC Stay in Your System?

Studies are being conducted to determine the safety parameters of using THC and other ingredients of marijuana in medicines.

Marijuana or weed is an illegal drug which is most widely used. Tetrahydrocannabinol or THC, an active ingredient in this drug, can stay in your system for 2 - 90 days. Predominantly, how fast THC is metabolized determines its stay in an individual's system. There are a minimum of 80 different metabolites that are formed from THC.

These metabolites are stored in the fatty tissues of various organs and are slowly let out through the feces and urine. 9-carboxy-THC is one such metabolite, which is actually looked for in all the drug detection tests to establish the presence of THC in an individual's body.

There are various tests to detect the presence of marijuana in your system. They fall under the following two categories:

This category of tests is used to detect whether a person is presently under marijuana intoxication. This includes the saliva test and blood test.

This test is relatively new, so it's not widely used. It can detect THC within 1 hour of marijuana usage; however, it will fail to detect THC about 12 hours after last use.

Marijuana intoxication can also be detected with the help of a blood test, which is the most preferred method compared to the saliva test. THC can stay in the blood from a few hours to a few days; however, the blood carries it for the least amount of time compared to urine and hair.

This category of tests is used to detect whether a person has used marijuana in the past. This includes the urine test and hair test.

This is the most reliable of all tests since it involves double screening of the urine sample. As a result, there is a minimum possibility of false-positive test results.

This test can also be used to detect the use of marijuana since such substances can easily get deposited in the hair follicles. Moreover, these can stay there for years after an individual's last pot session. The hair test cannot detect one-time use of marijuana; however, it can be used to detect regular marijuana use for months. 

For this test, at least an inch of hair is usually collected from any part of the person's body such as the scalp, arms, legs, or pubic areas.

The following table depicts the approximate marijuana detection time depending upon the type of testing method and the frequency of drug use with the factors like type of user as one time, 2 time and so on and type of test as blood test or urine test.

One-time User

Blood Test: 6 - 24 hrs
Urine Test: 2 - 5 hrs to 1 - 6 days

Moderate User:

Blood Test: 2 - 3 days
Urine Test:  2 - 5 hrs to 7 - 13 days

Frequent User:

Blood Test: up to 14 days
Urine Test: 2 - 5 hrs to 15 days or more

Heavy User:

Blood Test: up to 14 days
Urine Test: 2 - 5 hrs to 30 days or more

The length of time required to detect THC in your system depends upon various factors, which are explained as under:

Body Fat Percentage: People with a high percentage of body fat are prone to longer drug detection periods.

Physical Fitness and Body Metabolism: People with poor health conditions or a weakened immune system have slow metabolic rates, resulting in longer drug detection periods.

Amount and Frequency of Drug Used: Chronic and long-term drug use have longer detection periods compared to single or infrequent use.

Quality of Drug Used: The higher the quality of marijuana used, the longer it takes for THC to leave the system, thus increasing the detection period.

Age: Aging slows down the body's rate of metabolism. This results in a longer drug detection period.

Urine pH: If the urine is highly acidic, then the drug gets metabolized faster, thereby, reducing the detection time.

Since THC gets stored in the fat tissues, it can take longer to be cleared from the system. Also, every individual has a different body structure and metabolic rate, which greatly influence the time it takes for the drug to leave the system.

Disclaimer: This story is for informative purposes only, and should not be used as a replacement for professional medical advice.