How Long Does Marijuana Last?

A typical high from smoking marijuana lasts about 2 hours. However, psychomotor impairment can persist, even after the initial high effects are gone. More on duration of action and effects of marijuana here.

minute read
Reviewed by: Dr. Manish Mishra, MBBS

ARTICLE SUMMARY: The duration of a marijuana high usually depends on mode of administration. Additionally, the effects of marijuana vary by individual. We review marijuana high effects on the body and brain here. Then, we invite your questions about marijuana at the end.


How Does Marijuana Work?

The main active chemical in marijuana is THC, delta-9-tetrahydrocannabinol. THC is the psychoactive agent that creates main effects. How? THC binds to cannabinoid receptors in the central nervous system and interferes with important neurotransmitter systems involved in physiological, psychomotor and cognitive effects.

Certain areas of the brain, such as the hippocampus, the cerebellum, the basal ganglia and the cerebral cortex, have a higher concentrations of cannabinoid receptors. So, when you smoke weed, you also influence the physical areas that are in control of:

  • Concentration
  • Coordination
  • Memory
  • Pleasure
  • Sensory and time perception

Additionally, a person using marijuana may also become aware of normal, automatic, non-conscious muscle tension, movements, feedback, and control processes. Still, the effects of marijuana on mood often varies from person to person. In general, emotions can become exaggerated, which makes the user act inappropriately in regular situations. Marijuana can affect IQ, especially in adolescents.

Brain Effects

Marijuana effects are highly dependent on several factors related to the administration of marijuana and marijuana’s quality in general. For example, if marijuana is ingested orally, the effects will be milder but will last longer than several hours. Bear in mind that a first time marijuana user will not necessarily feel the same high effects as a chronic user; effects will vary from euphoria and panic to no effects at all.

Main brain effects of THC include:

  • Changes in mood
  • Delusions (when taken in high doses)
  • Difficulty with thinking and problem-solving
  • Impaired coordination and motor skills
  • Impaired memory

Hallucinations and psychosis may be triggered in high dose THC strains of marijuana or cannabis. In fact, long-term marijuana use has been linked to mental illness in some people, such as:

  • Temporary hallucinations
  • Temporary paranoia
  • Worsening symptoms in patients with schizophrenia, a severe mental disorder with symptoms such as hallucinations, paranoia, and disorganized thinking

Marijuana use has also been linked to other mental health problems, such as depression, anxiety, and suicidal thoughts among teens. However, study findings have been mixed.

Body Effects

The physical, short term effects of marijuana or cannabinoid use include increased heart rate and either higher or lower blood pressure. This is because within a few minutes after inhaling marijuana smoke, a person’s heart rate speeds up, the breathing passages relax and become enlarged. The heart rate may increase by 20 to 50 beats per minute or may even double in some cases. , Additionally, blood vessels in the eyes expand, making the eyes look bloodshot.

The main body effects of marijuana include:

  • Head rush or dizziness
  • Increased heart rate
  • Changes in blood pressure
  • Slowed digestion
  • Distorted perception

Longer term effects include some problems related to the body. For example, marijuana raises heart rate for up to 3 hours after smoking. This can increase the chance of heart attack. Older people and those with heart problems may be at higher risk. Other issues include:

Breathing Problems. Marijuana smoke irritates the lungs, and people who smoke marijuana frequently can have the same breathing problems as those who smoke tobacco. These problems include daily cough and phlegm, more frequent lung illness, and a higher risk of lung infections.

Fetal Growth. Marijuana use during pregnancy is linked to lower birth weight and increased risk of both brain and behavioral problems in babies. If a pregnant woman consumes THC, the drug may affect certain developing parts of the fetus’s brain. Children exposed to marijuana in the womb have an increased risk of problems with attention, memory, and problem-solving compared to unexposed children. With regular use, THC can reach amounts in breast milk that could affect the baby’s developing brain. More research is needed.

Intense Nausea and Vomiting. Marijuana causes a condition called “Cannabinoid Hyperemesis Syndrome” causes marijuana users to experience regular cycles of severe nausea, vomiting, and dehydration, sometimes requiring emergency medical attention.

We would also like to point out the effects marijuana has on driving. Marijuana can affect driving capabilities up to 3 hours after administration and includes judgment about distance, as well as attraction to light and sleepiness, particularly affecting prolonged and monotonous driving routes.

Factors that Influence Effects

One factor that will affect the effects of marijuana is the type of cannabis consumed. Some strains will affect your brain or body more than others. Still, the main factors that will influence the way weed works on the brain are unique to you. These factors include a person’s:

  • Age, height, weight, and general health
  • Amount of THC found in the dose
  • Concurrent use of marijuana with other drugs
  • Environment
  • Level of tolerance to THC
  • Mode of administration
  • Personal expectations
  • Previous experiences with or exposure to marijuana

How Long Effects Last

Effects of smoking marijuana are noticeable within minutes after the first toke, and usually reach peak levels after 30 minutes. Most physical and psychological effects of marijuana will return to normal within 5 hours after administration, with exceptional strains or high potency THC effects reported to last for 24 hours.

Marijuana Time in the Body

The active ingredient in marijuana, THC, enters the body’s bloodstream rapidly after smoking marijuana. If marijuana is ingested orally, it takes longer to be absorbed into the blood, usually from 20 minutes to 1.5 hours. But how long does THC stay in the system?

Once in the blood, THC is rapidly metabolized into molecules known as metabolites. At least 80 different metabolites are formed from THC. The majority of THC is excreted by the feces, about 65% of it, and over 30% leaves the body via the urine, although a very small amount of unchanged THC leaves the system intact. In urine, THC is noticeable up to 3 days after the last dose of marijuana.

However, chronic use can be detected weeks or months after last use. And as with any other drug, the hair follicle drug test detection time for marijuana is a minimum of 90 days in a single human hair.

THC detectable in Blood
Single use: Up to 24 hours
Frequent use: Up to 3 days
Regular, daily use: Up to 1 week

THC detectable in Hair
Single use: Up to 90 days
Frequent use: Up to 90 days
Regular, daily use: Up to 90 days

THC detectable in Saliva
Single use: Up to 24 hours
Frequent use: Up to 3 days
Chronic, heavy use: Up to one week

THC detectable in Urine
Single use: Up to 24 hours
Frequent use: Up to a few weeks
Chronic, heavy use: Up to one month

NOTE HERE: When marijuana is ingested, the liver breaks down THC into non-psychoactive marijuana metabolites, which are stored in the fatty tissues. This is how marijuana can be detected for longer periods of time in chronic, regular users. The metabolites are stored in fatty tissues and only released over time.

Getting High Effects

A wide range of effects may occur during a marijuana high, which vary in their intensity and quality. Among the most common and easily noticeable effect of marijuana high is the intensification of sensation and increased clarity of perception. Visual perception can change, colors seem to be brighter, patterns and graphic design are easily recognizable. Among other possible effects of a marijuana high are:

  • Appetite stimulation
  • Changes in perception of pain
  • Changes in perception of time
  • Enhanced sense of taste and smell
  • Increased fidelity and dimension of music
  • Intensified sense of hearing
  • More sensitivity to heat, cold, and pressure receptors
  • Objects appear more visually distinct

How Long Does A Marijuana High Last

The duration of a marijuana high is highly dependent on several factors. For example, if you are using marijuana daily, the high will last less than for someone who smokes occasionally due to drug tolerance.

Generally, marijuana highs usually last for about 2 to 3 hours. A typical high from smoking marijuana lasts for about 2 hours. Orally ingested THC or marijuana can trigger a high that lasts for longer, about 4-6 hours.

However, psychomotor impairment can remain after the initial high effects have worn off. Most common among these after effects are irregular time tracking, hand and eye coordination, or memory gaps.

Signs of a Problem

Compared to those who don’t use marijuana, those who frequently smoke weed or use marijuana in large amounts report the following:

  • Lower life satisfaction
  • More relationship problems
  • Poorer mental health
  • Poorer physical health

People also report less academic and career success. For example, marijuana use is linked to a higher likelihood of dropping out of school. It’s also linked to more job absences, accidents, and injuries.

But how do you know you’ve got a problem?

The first sign of a problem is drug dependence. Many people who use marijuana long term and are trying to quit report mild withdrawal symptoms that make quitting difficult. These include:

  • Anxiety
  • Cravings
  • Decreased appetite
  • Grouchiness
  • Sleeplessness

The second sign is that you can’t control your use. If you smoke all the time or can’t quit on your own, it’s possible that you’re experience marijuana use disorder. An estimated 30% of regular users are actually addicted. And many don’t know it!

Regardless, the best way to find out is to get a diagnosis. You can contact your physician, an addiction doctor, a psychologist, a psychiatrist, or a social worker for an initial screening. These medical professional

Let’s verify your coverage for treatment at an American Addiction Centers location. Your information is always confidential.


Your Questions

Still have questions?

Please leave your questions in the comments section below. We’ll do our best to respond to all real life questions with a personal and prompt reply.

Reference Sources:

NIDA: What are marijuana effects on health?
New England Journal of Medicine: Adverse Health Effects of Marijuana Use
National Academies: Health Effects of Cannabis and Cannabinoids
National Highway Traffic Safety Administration: Cannabis, Marijuana & THC
Hazardous Substances Data Bank: TOXNET for delta 9-Tetrahydrocannabinol
National Institute of Drug Abuse: Drug Facts on Marijuana


About the author
Lee Weber is a published author, medical writer, and woman in long-term recovery from addiction. Her latest book, The Definitive Guide to Addiction Interventions is set to reach university bookstores in early 2019.
Medical Reviewers
Dr. Manish Mishra, MBBS serves as the Chief Medical Officer of the Texas Healt...

All of the information on this page has been reviewed and verified by a licensed medical professional.

I am ready to call
i Who Answers?