The effects of marijuana fade quickly, but the drug can be detected 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.
Although a number of states in the U.S. have active medical marijuana laws and recreational use of marijuana for adults over the age of 21 is legal in 11 states, Washington, DC, the Northern Mariana Islands, and Guam, the federal government continues to classify marijuana as a Schedule I controlled substance.
The FDA has not yet approved medical marijuana for any medical indication, but it is often prescribed for chronic pain, nausea, HIV, multiple sclerosis, glaucoma, and irritable bowel syndrome (IBS).
How Long Does It Take to Feel the Effects?
The effects of marijuana can vary from person to person. Some people may feel euphoric and relaxed while others feel anxious and paranoid. In other cases, people report feeling “dopey” and experience a loss of interest in activities or an inability to grasp concepts.
If marijuana is ingested orally rather than smoked, it takes longer to be absorbed into the blood, usually from 20 minutes to an hour and a half, but this can vary based on the amount taken as well as physiological factors such as absorption and rates of metabolism and excretion can influence drug concentrations in circulation.
Effects can be far-ranging depending on the strain, method of consumption, and amount and can include the following:
- Dry mouth
- Swollen eyelids
- Bloodshot eyes
- Pleasurable body sensations
- Increased appetite (“the munchies”)
- Distorted perception (sights, sounds, time, touch)
- Loss of coordination
- Trouble with thinking, memory, and problem-solving
- Increased heart rate
The short-term effects of marijuana on memory, learning, problem-solving, and coordination last for one to two hours, with some lingering effects for up to 24 hours.2 It’s been shown to impair your driving performance for up to three hours, according to the National Highway Safety Administration.
The effects of marijuana are also influenced by the terpene profiles of a given strain. For instance, citrus terpene profiles tend to be more stimulating, which may be the desired effect, or may contribute to someone feeling anxious.
How to Get Marijuana Out of Your System
Many employers have a workplace drug policy that includes random drug testing for current employees and routine testing for all new job applicants.
If you are required to take a urine test on short notice for employment or other purposes and you have recently smoked marijuana, you are probably going to fail the test. This is particularly true if your use is regular or heavy.
The only completely reliable way of passing the test is to stop smoking or ingesting marijuana or cannabis products.
Although you will see many tips on how to beat a marijuana drug test, most have proven to be urban legends. Some of these questionable techniques include the following.
Washing Your System Out
This method entails drinking a lot of water or liquids and urinating several times before the test, then taking vitamin B-12 to add color back to the urine. Although this may lower the percentage of THC found in the urine by diluting it, it will not totally eliminate THC metabolites.
Some people will also try to exercise before the test, but that can actually backfire, depending on the test, as it can release stored THC from fat into the blood, according to one study in the journal Drug and Alcohol Dependence.
Using Drug Screening Agents
Some companies sell various substances and herbal teas that are allegedly capable of “cleaning” the body’s system of traces of marijuana. There is little evidence that any of them actually work. The catch is that most of them have to be used over an extended period of time, during which the body will naturally eliminate THC anyway.
Tampering With the Test
This involves adding something to the urine to contaminate the sample. There are tales of using Visine, bleach, salt, or detergent to the urine sample, but these items are easily detected by the lab.