According to Ryan Vandrey, an associate professor of psychiatry and behavioral science at Johns Hopkins University, there is no typical window of detection for marijuana. The duration for which it stays in the body is highly variable from person to person and it varies based on the frequency of use and the amount of use. Some factors that influence the time taken for its removal include:
- Dosage of the drug (amount of THC):
The dosage of the drug taken, or the amount of THC administrated in the body is proportional to the time taken for its removal. If a person has smoked more quantity of marijuana, the window of detection will also be prolonged.
Establishing the amount of marijuana consumed can be a tricky task. Even a small amount of marijuana rich in THC is enough to elicit an extreme response. So while consuming the drug, it is important to keep in mind the concentration of THC present.
As stated earlier, long term and frequent users are likely to retain the drug in their system for longer periods of time. This is because with prolonged use, body is supplied with excessive amounts of THC that tend to accumulate in certain body tissues such as fat and hair. Over time, the stored drug is gradually released and removed from the body. As a result, the person tests positive for a much longer period. Greater the amount of stored THC and its metabolites, longer will be the time taken for its removal.
Marijuana can be consumed in a number of ways such as:
- Smoking it in the form of joints of blunts
- Eating marijuana containing brownies or gummies
The mode of administration influences the way THC is absorbed, metabolized and excreted from the body.
In case of smoking, THC is directly absorbed in the blood via lungs. As a result, the effects produced by it are quick. The blood levels of THC reach their peak values within 10 minutes of smoking and they are just as quick to fall. In case of most occasional or first time users, the drug levels drop by 60% after the last puff. Within 3-12 hours, the levels fall below detectable range.
Consuming marijuana edibles such as brownies or candies produces slow and long lasting effects. As the drug is slowly absorbed into the blood from GIT, it may take 1-5 hours to feel the effects. The time taken for the drug to reach its peak values in the blood depends upon the concentration of THC in the oral formulation. Usually, the blood levels of the drug begin to fall within 24 hours of last consumption. However, some metabolites from the drug may be present in the blood for as long as 50 hours post ingestion.
Individual factors such as age, gender, metabolic rate etc also influence the clearance rate of the drug. Some people are likely to clear off the drug faster than the others even after consuming the same amounts.
Factors like height, weight, fat content, gender and age of the user influence the time taken for its removal. People with more fat content have a hard time removing the drug from their system since it gets accumulated in fat cells. Likewise, people with more body mass are quicker to remove it than the people who take high amounts compared to their body mass.
Metabolic rate of a person plays a key role in determining the time taken for THC removal. People with an active metabolism excrete the drug at a faster rate. People with slow metabolic rate take longer to convert THC into its metabolites.
Taking other substances in combination with marijuana can slow down its clearance rate. It is commonly combined with alcohol and the body has to work to remove both the substances simultaneously. However, some supplements can be helpful to speed up the process of THC removal.
An active and healthy lifestyle can facilitate the process of THC removal. Doing regular exercise and yoga can help to speed up metabolic rate. Heavy marijuana consumers with an inactive lifestyle may take longer to clear the drug from their system.