Mirtazapine - can you lose weight?

Posted , 20 users are following.

For those of you struggling with your weight loss whilst taking this drug, I thought I’d tell you about my experience and conclusions.

I started on mirtazapine around 4 years ago for major depression and nausea/lack of appetite, and it worked really well for me, banishing my depression within days, and reviving my appetite and enjoyment of food. It also virtually cured my migraines, stopped my itching and IBS, and helped me sleep and cut my temazepam right back to around once a fortnight.

I quickly gained weight which I put down entirely to my increased appetite. I thought all those stories you here about not being able to lose weight despite cutting calories were just people underestimating how much they consumed. I was wrong.

After 6 months on the drug I had gained 26lb and none of my clothes fitted me. Despite cutting my food intake down, I kept gaining weight. In desperation, I came off mirtazapine cold turkey and suffered the most awful withdrawals. After ten days of hell, I was forced to go back on it. But I had dropped 7 lbs. I managed to keep my weight stable at 152-154lbs for two years. I couldn’t eat what I used to eat, but at least I was no longer gaining weight. Then in January this year, I saw a picture of myself in a bikini and hated the way I looked. I decided to seriously slim.

January 2015 I weighed 152lbs and cut my calories to between 1500 and 1800 a day. The weight fell off and I got down to 143lbs by March. I thought once again that mirtazapine was not affecting me being able to slim. I was wrong.

April 2015 I stalled, despite keeping to my diet. So I added a daily cardio work out. I actually GAINED weight!

July 2015 I still weighed in at around 143lbs as I had lost the weight I gained in April but after 7 months was no further on than I was back in March. I was forced to recalculate my maintenance level of calories from 2000 down to 1800. I have an active job and being 5 ft 10, I should need more calories than this to maintain my weight. I realised then that mirtazapine was interfering with either my metabolic rate, or my ability to burn fat or both. I still couldn’t lose any weight.

August 2015 I cut out alcohol which meant that I had effectively cut my calories still further and I have lost a further 2lbs. I now weigh 141 lbs.


Mirtazapine affected my weight by increasing my appetite AND by some other means, probably slowing my metabolism and interfering with my fat burning process. You CAN lose weight on mirtazapine, but it is much harder than if you are not on it. Is it worth it? Well yes, for me it is. It has turned my life around for the better. I love it, and I hate it. I love it for helping me fight my depression, sleep well, be free of migraines and IBS, and not have to take antihistamines daily for my itching. I hate it for forcing me to stay on a rigid diet with very few indulgences, and for being such a difficult drug to kick.

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  • Edited

    Great post Evergreen. I've been on Mirtrazapine for about 16 months now - initially at 15mg then slowly tapered over 1 year down to 3mg. Then had a relapse (I have severe but episodic insomnia that then causes extreme anxiety meltdowns). Now I'm back at around 18mg after a rocky summer of bouts of insomnia. On the weight side, you are 100% right that it doesn't only cause weight gain due to an increased appetite. I've always been on the slim side (around 119 pounds) and watched what I eat. Without a shadow of a doubt I eat better/less now than I did before being on Mirt and I have still put on 28 pounds since taking it that I absolutely cannot shift. I went on a very strict low carb diet in Jan 2020 when my dose was around 5mg and managed to lose about 8 pounds but it was such hard graft. As I got down to 3mg I started to see a few pounds more come off and I was probably down to about 16 pounds over my natural weight at that point. Then after this summer of needing to increase back to 18mg, it's all gone back on despite again not making any changes to what I eat.

    As for the Mirt itself - at first it quite literally saved my life after my mental health deteriorated severely after nearly 7 nights of not sleeping at ALL. It was the only thing that worked for my insomnia. 15 months on however and it has now lost that effect . I wondered if you (or anyone else) has experienced that loss of efficacy on sleep? I'm very aware that it's supposed to be more sedating at lower doses but I can't seem to get any lower at the moment without having another episode of insomnia and upping the dose in desperation at the time to help me sleep! It seems such a cruel twist of fate that all ADs that are sedating also cause weight gain through their mechanism. Evergreen have you experienced any changes in how it works for your sleep?

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  • Posted

    I have arrived here as i am now taking Mirtazapine 45mg. This is a new drug for me as i was previously taking sertraline but it wasnt doing much for me. Before starting on Mirtazapine i began to lose weight but now i have gained what i lost and more. I am currently at the heaviest i have ever been and i hate it. Side affect wise it has been rough at times. I have the increased appetite. i am hungry all the time and my sweet tooth has gone crazy. I get fluid retention and swelling of my legs it can feel like the skin wants to burst when I try to walk when this happens. It’s made my joint pain worse and for a while it did really affect my orthostatic hypotension. For the first week of being on 45mg I couldn’t be sat upright for long periods. Despite these side affects it has helped my mood and I am feeling better although slightly down because of the side affects.

    I hate that I’m gaining weight while on this drug but im trying what I can to at least stop gaining and maintain what im at. I have other health conditions too which make me worry too as I have orthostatic hypotension, hypermobility and PCOS. My biggest concern is gaining weight and not being able to shift it because of the PCOS. I am as active as I can be with the increase joint pain and hypermobility. The pain is sometimes unbearable and will wake me up and keep me up at night.

    After reading how strict you guys have had to be with exercise and diet just to maintain and lose some weight I’m starting to think that I may have to try a different drug and risk getting bad again. I have shared my concerns with my doctor and they want me to see how I go for longer in hope that the side affects will settle down. But Before I got really bad they kept going on about how fat I was before and how I needed to lose weight because of the PCOs. I understand that alive and fat is better than the alternative but surly they should be sharing my concerns too

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  • Posted

    Hi to all,

    i hope i will not gain weight on it i need to loose weight not gain it as i am loosing weight now i dont want to gain it back hopefully i wont.

    Dose it help with Sleep at all.


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    • Posted

      Hi Irene. My doctor warned me about the weight gain when I went on so it is a recognised side effect. it is, however, good for sleep. Strangely the lower doses are known to be more sedating. Hope it works out for you

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  • Posted

    thank you so much for your help. I was wondering if I would stick to diet what would happen to my weight since I am struggling so bad with this thing.

    now I think I have to try to stop it.

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    • Posted

      Hi Roda. Mirt seems to slow down your metabolism in addition to giving cravings for carbs and sugary junk. There are several papers on this if you want to read more about it. Mirt was quite good for me as far as sleep goes but I just can't cope with the food issues. I'm currently weaning off it. Good luck to you

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  • Edited

    I have suffered with depression and anxiety for many years and thought I could beat it on my own...I couldn't..I contacted my doctor in October and I was put on sertraline but these gave me headaches, sickness and made me more suicidal. After three months she prescribed me mirtazapine. I have been on these since February now and I don't have any side effects at all and they lift my mood so much. Only downside I have to these is that my weight has gone up and I am hating it. My clothes don't fit me and I have tried the losing weight method but nothing is working. I don't know what to do. Do I stay on them and pile more weight on then be depressed again or do I go cold turkey for awhile?

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