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Brain Fog is a Common Marijuana Withdrawal Symptom

By April 7, 2021July 27th, 20213 Comments

The experience of brain fog is in the name itself: it’s like a haze that drifts over your mind, affecting your ability to think, reason, remember, or concentrate.

According to the Merriam-Webster dictionary, brain fog is “a usually temporary state of diminished mental capacity marked by inability to concentrate or to think or reason clearly.”

With cessation of marijuana, you might feel as though your brain just doesn’t seem to work as fast as you want it to. Some people describe feeling as through their brain and body are out of sync with each other. Other people experience more difficulty with concentrating on tasks, or difficulty with memory. As with other withdrawal symptoms, the cognitive difficulties you may encounter will be unique to you, and represent your brain recalibrating its neural circuity from extended marijuana use.

Again, there’s biology to explain why you’re feeling slow. More importantly, there’s also biology to explain why brain fog is not permanent. Acute marijuana intoxication is akin to putting your brain through a mental meat-grinder. In scientific studies, that translates to measurable impairments in verbal memory, attention, and basic motor coordination (Crean, J Addict Med, 2011; Broyd, Biol Psychiatry, 2016).

There is further evidence to suggest that acute intoxication interferes with higher-level brain functions like planning, organizing, problem solving, decision-making and risk-taking, which are collectively referred to as executive functions.

Impairments in executive function will continue in the hours to days after stopping marijuana use and may last up to a month (Crean, J Addict Med, 2011). You will notice that some things, like your coordination, attention span, and short-term memory recover faster than others. That’s normal. Depending on how long you’ve smoked for, and how much you smoke, it may take longer for your brain to recover. By approximately 1 month, however, the differences in executive function in former heavy users and non-users approaches zero (Pope Jr, J Clin Pharmacol, 2002).

To summarize, the ultimate cure for brain fog is time. In the meantime, though you can optimize your actions and routines for your daily functioning. Eating healthy, exercising, and maximizing your sleep can help boost your brain processing while it’s on the mend from chronic marijuana use. If you’re having difficulty remembering tasks or items, make reminders for yourself with lists or alarms on your smartphone or devices. Be patient with yourself—we believe in you.

Would you mind answering a few questions (anonymously)?

Currently, little data exists on brain fog and marijuana use. is collaborating with researchers to explore this topic and others. We have created a short, anonymous survey which we will use to focus our future research efforts.

Your participation is appreciated and completely anonymous. You may skip any questions that make you feel uncomfortable and you are free to withdraw at any time. is a free, web-based resource and community created by a team of healthcare professionals and researchers. We distill the facts about marijuana use and its effects into practical guidance for interested persons or for those who are thinking about or struggling to quit weed. Finding reliable, easy to understand information about marijuana should never be a struggle—that is why our core mission is to provide the most up to date information about marijuana use, abuse, addiction, and withdrawal. While we seek to empower individuals to have control over their use, we are not "anti-weed" and we support efforts to legalize adult marijuana use and study.

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  • Jim says:

    I am 65 .I started smoking pot when I was 16.When I was working every one had to take a urine test on thier bday. Every one knew tobbe ckean.I know now thc % was 4% .I never had any problems cleaning up in a month .I retired when I was 62 and was smoking every day all day. 2 years ago I got medical marijuana. I was smoking 81 % oil and 40 % flower every day all day. I couldn’t figure out why I was losing weight, had bad anxiety and brain fog so bad I felt like I had lead in my head .I decide I needed to quit and see if pot was the problem. I never would have believed that pot could clyde withdrawals because I quit many times for the work urine test. I found out I was wrong. It’s been 2 1/2 months since I quit .I had crazy vivid dreams all night for a month .I still have them but not ass long or as vivid .I was angry and irritable for 2 weeks .I put on 25 pounds in 72 days that I needed to put on.I still have bad brain fog / lead head when I lie down .Its not as bad when I get up. I am hoping it goes away ..Its hard to deal with .

  • Richard Chalmers says:

    Day 19 cold turkey…day 1234 nightsweats of an night seats..disapeaerd after week.loss of apetite…major anxeity depresion..cognitive motor skills..difficuilty thinking ..

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