Testing For THC:
How They Do It And How Long It Remains In Your System
Throughout the years cannabis users have been trying to pin down how long cannabis can be detected in urine, blood, saliva and hair. Science has begun to narrow it down quite a bit, however, as with all thing’s cannabis, there is no real linear one sized fit all answer.
The main factors which determine the length of time THC stays in the system are the amount of body fat a person has, how often they consume cannabis, how much they consume and the sensitivity of the drug test.
“How much you consume and how often will influence how long cannabis stays in your system, but it can depend on an individual’s metabolism as well,” says April Hatch, RN, co-founder of Cannabis Care Team, a nurse-founded Cannabis education group.
THC is a lipid soluble chemical, which means it binds to fat in the body which increases the length of time is takes to eliminate it completely. Meaning, frequency of use will determine how quickly THC or THC byproducts leave your system.
There are four classifications of cannabis use. Single use, moderate use, chronic use and chronic heavy use. These are the biggest determining factors in passing a drug test. Those in the single use category, could likely pass a drug test in three days. However, if you fall into the chronic heavy use category, it could take 30 days or more.
There are various methods to test for THC in the human body. Each way will vary in its collection and sensitivity.
Urine tests are the most common practice used to look for THC, they are broken down as follows. Please note- this is the general rule and will vary for everyone:
- Single Use: 3 Days
- Moderate Use (four times per week): 5-7 days
- Chronic Use (daily): 10-15 days
- Chronic Heavy Use (multiple times per day): more than 30 days
Blood tests are typically used to detect recent use, generally between two to 12 hours. However, in cases of chronic or heavy chronic use, it can be detected up to 30 days through a blood test.
Saliva testing has a short window of detection, it will show same day use. Frequent smokers have shown THC in their saliva up to 72 hours of last inhaling cannabis.
Hair follicle testing can detect THC up to 90 days after use.
THC is broken down in the liver. It has more than 100 metabolites, but the most significant ones are 11-OH-THC (11-hydroxy-delta-9-tetrahydrocannabinol) and THCCOOH (11-nor-9-carboxy-delta-9-tetrahydrocannabinol).
Drug tests look for these metabolites, which stay in your system longer than THC. These metabolites are excreted from the body via urine and feces. Frequency of use will determine how long it takes the body to perform its function.
Essentially, there are several contributing factors as to how quickly THC will leave your system. Body mass index and an individual’s metabolic rate will govern how the human body will process and metabolize THC.
The more frequently you use cannabis and the higher your BMI, the longer THC will be detectable in your system.