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Weed Withdrawal

Brain Fog is a Common Marijuana Withdrawal Symptom

By April 7, 2021December 17th, 202126 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 one 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.

About 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.


  • 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 .

    • Omar says:

      Hi Jim, I know this is an old post. I’m just curious on how you are doing now, I haven’t smoked as long as you have however I am experiencing similar symptoms. Did the brain fog ever go away?

  • 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 ..

  • Anonymous says:

    I smoked for last 5 year.. Too hard on weed and my whole 5 years were on weed and high.. It’s been nearly 1.5 years after quitting weed now.. I still am not recovered..each day is like a huge recovery… The best thing to recover personally, mentally, physically is to have holy pilgrimages, joing gym, having good conversation with good one, movies, healthy food and we must and should have a time table if we think of the recovery.

  • Anonymous says:

    Been a smoker for 5 years consistent. Music, Exercise, movies, and eating healthy as well as surrounding myself with people whom I love, have helped me get through a lot of the withdraw process, although it does come back in moments, I’m rest assured it will end, Everything ends, you’re not alone, stay strong keep pushing forward don’t let the plant dictate who you are, at the end of the day it’s your body and your mind and with each passing day it’s slowly being pieced back together, Just keep that picture in your mind of the awesome senses you once had but lost along the way, you’re gonna regain them it’s gonna take time but it’ll all come back, much love and strength to those who might be reading this.

  • Chronic User says:

    I have been a longtime THC user, approximately 25 years. All day every day user except when I need to work or perform other duties that require a clear mind a focus. I am not trying to stop consumption completely, only decrease my tolerance and remedy my overuse//abuse to cope with pandemic as an ICU nurse. I always experience (by day 2) night sweats, vivid nightmares, extreme brain fog and forgetfulness, difficulty focusing and concentrating on tasks, difficulty with cognition, and lack of appetite.

    • 420somewhere says:

      I have similar issues, I’ve been smoking daily for a year and had to stop to take drug screen also for hospital job. Feel restless and brain fog. Lost track of time today on day 5 and sweating but day 1-4 was mild.

  • Zoey Hendrickson-Swan says:

    Currently been on week 2 after smoking weed vape. Had I guess a little bit to much and got to high. This has almost been two weeks of brain fog, I’ve stopped smoking the vape that day, have completely cut coffee and tobacco, just wanting to feel like I am actually living again. I just feel like my brain is mush..

  • Misty says:

    Day 19 quitting after 4 years. Brain fog, mood swings (anger), anxiety, vivid dreams, cravings once a day. Be glad when I feel better.

  • Anonymous says:

    I’ve stop smoking now for 4 months still getting fog brain and sometime stomach pain feeling tired in the brain all day then dopes off evenings time feels like there no end to it could go on for 6 months

  • LOVE2023 says:

    sometimes by reading stories of people it can help or sometimes even remove hope. by reading comments sucks as 6 months now and still a lot of brain fog… sometimes i wonder if these people were not taking something else too, other drugs, alcohol, medicine… this can scare people trying to quit. How do you think someone who’s trying to quit at his first week and come here to read people after 8 months are still feeling like shit…

    to people who have ONLY weed problems. dont worry it will get better fairly quick. dont think you will feel like shit for months and years… its a natural plant… if you still feel terrible after months you probably have to improve other aspects of your life such as sleep, what you eat, what you do with your life…

    its not as bad as some people say here. because here we see people on big difficulty writing their stories however there hinders or thousands that are feeling great after quitting. their lives becomes beautiful. just sad that many of them dont come here to post their stories.

    im at day 7 and By reading some stories it almost made me gave up however I remembered that after 1month you do get ALOT better. good luck to everyone and specially the ones that its difficult for them. stay strong amigos its worth it. smoking weed = wasting precious moment of life you will never get back. life is precious. I LOVE YOU ALL 🙂

    • Rafau Roncaletti says:

      Exactly what I needed to read! On day 39, experiencing some mild brain fog. I went through some heavy emotional time a couple weeks back though. I’m almost sure the brain fog is linked to that as well. Getting professional help soon 🙂 staying positive. Glad I stopped smoking

    • Anonymous says:

      Thanks for this!

    • Alex says:

      Thank you!
      I quit 3 days ago because I feel that it’s very much affecting my mental health with hopes to feeling better in the next few weeks and these comments really made me lose hope. I just needed to see 1 positive experience 🙏🏽

  • montreal514 says:

    I just realized an important factor about weed people dont seems to consider. There’s the strength of the weed you’re smoking and the quality. I live in canada. used to smoke when it was still illegal in canada. Buying weed from the street realized that sometimes either people were adding chemicals or it was the fertilizer still on the weed. Now I realized that during that time, i tried to quit a few times. The side effects were really more terrible then now that i was smoking weed from the official government store. I think a lot of people smoke chemicals stuff. I dont think it’s normal that you are sweating after 6 months. that is really not normal from weed only. even if you smoke 5 grams per day for years. Im on my first week, i already feel great. sleep well, my mood improved, i feel motivated happy and good. actually it’s not that hard. one trick, try to do it on a trip. im in cuba now for vacation. it was only hard for 1 day. second day its like i wasn’t even thinking about it. try to start your momentum of quit in a new environment. it will be 100 times easier. try to find good suppliers too of weed… its just sad that there still many places its illegal when in fact and it proven the weed is a lot less dangerous than alcohol. and also ive never seen people wanting to fight on weed. however alcohol can make people become very very stupid and sometimes dangerous. what a stupid system we live in. alcohol is fine but weed you might go to jail. sooo stupid. good luck friends, i promise its not that hard. dont make your opinion on a few posts here of people feeling like shit after 6 moths. that is not normal, not from smoking weed. keep in mind people writing they feel like sheet after 6 months is maybe 1% of the cases however they are 80% of the posts. because people who successfully quit and feel great, they dont come on these forums anymore. they dont need it lol, they turned the page on their life. im here because i know those comments can scare you, it did to me. keep in mind those cases are rare. weed is not like crack or crazy stuff like that… dont think you will be in nightmare for 1 year. its false. you will great after 1-2 weeks. i promise and will keep improving. your dopamine baseline will reset. Dr Huberman on YouTube please watch his videos about dopamine and motivation. to understand how your brain works is the key to be successful. i still dont understand how come we dont learn how the chemicals in our brain work. this stuff should taught in elementary school. you need to understand your body to have better chances. im not affiliated in any way with Dr Huberman. he only changed my life, a HUGE impact and maybe it can for some of you here. good luck everyone 🙂

    • Anonymous says:

      This post gave me a huge relief. I’m currently on day 3 of no weed and the symptoms are less than ideal to say the least. Knowing that within a couple weeks you’ll see vast improvements is enough of a reason to keep going. Thank you and good luck to everyone else as well 🙂

  • Stephen says:

    I’m going on day 90 of being sober the last 3 months have been terrible I’ve had some bad anxiety trouble sleeping horrible brain fog that never leaves and it feels like im always high but im not and anytime I’m around light my head feels weird I feel like im stoned 24/7 the brain fog never left im at the point where it’s too much to bare I miss the person I was 3 months ago I just feel like a different person

  • Anonymous says:

    Hi guys,

    I want to know if what i’m feeling is indeed brain fog or not…
    I feel like my brain is heavy and I can’t think super deep ,like for example when I need to write a text or problem solving thinking it’s like some receptors of my brain are burned or something, like my brain is just CLOSED and I can only think surface. it’s super frustrating and i’m scared if it might not be brain fog but something more serious… I’m on day 3 of stopping smoking after almost 2 years of being a regular smoker, and I even feel like i might have started experiencing these brain symptoms one or two days before stopping thats why i’m confused/scared if it might be something more serious…

    Would truly appreciate if someone could bring some clarity to my confusion 🙂

  • Rosie McCutcheon says:

    I smoked pot back in the day from age 19 to 31. Then I stopped, got married, had kids. Did not touch pot and very little alcohol until age 60. The weed today is unbelievable and so much stronger! For the past ten years, would smoke maybe two or three hits every evening. Have quit a few times for one to two months, just to clear my head. Recently, someone sent me some pre-rolled joints from a dispensary that were 41% THC. The high from those joints was almost debilitating, even though I still would only take a couple of hits in the evening. Got sick about three weeks ago and stopped cold turkey. The first two weeks, could not tell if symptoms were from this horrible cold or pot withdrawal. Third week, I’m over most of the cold symptoms, but am still having trouble sleeping and can barely get up in the morning, even after 10 hours of sleep (This is not normal, and I generally only need 7-8 hours of sleep. I still work). Brain fog is unreal, coupled with a feeling of heaviness in my body that lasts till about noon or one each day. I have decided I should probably quit altogether, because I realized I was much more productive and creative during the thirty years when I did not smoke. I cannot do edibles b/c their effects are way too unpredictable. Hoping this brain fog ends soon!

  • Anonymous says:

    Haven’t even quit yet. Tapering off. If this is what I have to look forward to, I need to make out my will right now.

  • Erik says:

    34 years old. I have been smoking for almost 20 years on a fairly consistant basis. The last year or so I have been struggling mentally (divorce and unemployment) and over time this caused me to increase my intake significantly. For the last 10 months I have been smoking around a half ounce a week of super potent California herb. For a while I thought this was my only way to feel calm and normal. But the last few weeks everytime I smoke I keep going to the same dark place, and even with meditation I could not get out of it.

    So 4 days ago I stopped. My initial feeling is that everything that was bothering me is bothering me tenfold now. But this is normal. Anytime we change the wiring in our brains we will suffer in some way. I can say that day 4 is mildly better than day 1-3 was, this encourages me. Know that you’re not alone, and that even the most excruciating moments can lead to peaceful ones for all of us. We try to seek comfort from the evils and sadness of life. It’s not the plants fault, but our reliance on it to numb or make us ignore things.

    Also. Meditation is very important.

    Also Also I should have already stated I did this 10 years ago for months and started again. I’m not mad that I started again, more that I didn’t learn. It gets better folks!

  • Sar says:

    In my own humble view, I think it’s a pity that anyone on posts gets into putting anyone else down, especially when the topic is about health and even more so when it includes mental health.
    Why would anyone want to make themselves vulnerable by sharing their own story, only to then be ‘heckled.’ Isn’t there room for all?

    My own personal experience.

    I gave up toking weed on November the 1st. I needed to as life has become very challenging (I’ll spare you the details), and I knew I needed my ‘straight head’ back.
    I used weed for several reasons over the years:
    a. Casually i.e. socially
    b. To help with pain so I could keep the meds low so I could always up them later on if need be i.e. Trigeminal Neuralgia
    c. And to soften the edges of life experiences i.e. lots of trauma. CPTSD.

    Anyway, I wanted to quit weed a year ago, but I was really afraid of, albeit temporarily, but nonetheless significant (for me), phase of quitting weed, where thoughts are racing , as I’ve always been afraid I might end up psychotic.

    November the 1st I quit. helped along by my lovely dealer-friend getting busted. I capitalised on the opportunity.

    After a week has passed, I thought I had got away with it. But one of my son’s said fore him it kicked in around the 8th day and lo and behold, there was the whizzy state I had been afraid of. It lasted for two days.
    Then came two weeks of on and off sweats and chills (I was on a 30-day juice fast at the time, so that would have been impacting me, too). Within this period I had a few days of rage and I think all that I had been ‘cushioning’ via smoking weed, was in my face all at once. I was cutting a melon to juice one day, for example, and it flashed into my mind that it was someone’s head. I have never even hit anyone and am really anti-violence so that was unnerving, but it passed, too.
    This past week, I don’t have any symptoms other than being markedly ‘thick.’ It’s challenging to remember the words I need to speak mid-sentence, and especially challenging to work out anything other than one single thought. Anything more complex brings frustration and even anger.

    Notes/outliers to consider.
    1. I have had a very challenging ten years full of shock after shock.
    2. I had two root canals done 18th months ago and repeated infections, and now with a new dentist, will be getting a whole head scan to check the infection hasn’t spread. (This is why I am so keen to know the effects of the weed has gone, so I know what I’m left with).
    3. I have always dreamt a lot, vividly, lucidly, and remembered them – other than when I have been smoking weed, regularly. In this past week I am again aware of my dreams and sometimes remember them when I wake. I am not quite where I was without the effects of weed, but it’s something of a measure, for me.

    I probably sound like a fool to someone or another, but this is my study – and over the years, I have had many going friends, many quite due to experiencing paranoia. let’s face it the weed of today is not the weed we used to smoke back in the day, so to speak. The THC content used to be below 5% and is now between 45 and 100%.

    Personally speaking, I applaud anyone and everyone who has contributed to this post.
    To those who don’t have much experience, be warned that things can get very challenging and if you’re thinking about quitting now, it’s likely a good idea.
    Tp those who feel they want/need to go back to it, keep it clean and grow your own. Stay moderate and take breaks.
    To those who have smoked it forever, like me, you probably need a rest at the very least.}

    But hey, we’re all individuals and there are so many other things to take into consideration. Who am I to say : D


    PS. I concur with the commenter who mentions meditation. Not just for quitting weed but in any event. I don;t mean guided meditation, I mean practising emptying your mind altogether. There’s no greater high, to me anyway.

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