The effects of marijuana fade quickly, but the drug can last in the body for weeks and sometimes longer. The amount of time the active ingredients and breakdown products of weed remain in the system can range from a few hours to 90 days, depending on how often or how much marijuana the person has been using.
For example, a single dose of weed can stay in your system for up to 13 days, depending on the type of test used. If you rarely smoke weed or only have a few puffs, it will leave your system more quickly than if you use marijuana frequently or heavily.
How Long Does Weed Stay In Your System?
- Blood: Up to a few hours
- Urine: From 13 (for single use) to 90 days (for heavy use)
- Saliva: Up to a few hours
- Hair: Up to 90 days
Factors That Affect Detection Time
The length of time marijuana remains in your body depends on many different factors, including frequency of use, body mass, metabolism, sex, and hydration levels.
Frequency of Use
There is some evidence that the length of time that marijuana remains in the body is affected by how often the person uses marijuana, how much they use, and how long they have been using.
Sex
Women often metabolize THC at a slightly slower rate since they tend to have higher levels of body fat than male counterparts.
Metabolism
The faster your metabolism, which can be impacted by age, physical activity, and certain health conditions, the faster marijuana will exit your body.
Body Mass Index (BMI)
THC metabolites are often stored in the fat cells in your body, so the higher your body fat (or BMI), the slower you’ll likely be able to metabolize and excrete marijuana.
Hydration
When you’re dehydrated, you’ll have more concentrations of THC in the body. Flooding yourself with water won’t make you pass a drug test, however. Instead, it will dilute it and you’ll likely need to retake the test.
Smoking vs. Vaping vs. Edibles
The method of use also impacts the detection time. If marijuana is smoked or vaped, the THC levels in the body will drop faster than if you ingest it. Edibles take longer to break down in the body and leave your system.