SSRI Weight Gain

February 21, 2020 11:33 AM

All I've seen for a reason they can cause weight gain is that your appetite may improve as your depression lifts, stuff like that. I'm more into knowing whether there is something in the SSRIs that causes you to pack on weight despite no change in your eating habits. Something chemical, or related to metabolism, whatever.
posted by noelpratt2nd to Health & Fitness (20 answers total)

I gained around 50 pounds when I was on Paxil (also called Seroxat or paroxetine). It was awful. And most of the weight has remained long after I quit Paxil. For what it's worth, this article claims that the weight gain is due to the fact that Paxil is sedating (certainly true in my case), so you end up being less physically active. This sounds more like a reasonable first hypothesis than something that was rigorously tested. The article also mentions some other theories about why various antidepressants can cause changes in weight. I know that in my case, the Paxil did nothing for my depression (if anything, it made it worse), so I know the weight gain didn't happen as a result of an appetite increase caused by better mood.
posted by akk2014 at 11:46 AM on February 21, 2020 [2 favorites]

Response by poster: Mirtazapine did put some weight on me, but I dropped that. I'm now on Lexapro for six weeks and it seems that too, independent of eating or even physical activity, is putting on some weight. I hope it's not something I won't be able to manage, but fear it may be -- i.e., that it's just "built-in" to the medication.
posted by noelpratt2nd at 12:23 PM on February 21, 2020 [1 favorite]

Response by poster: Meaning I dropped the drug, not the weight...
posted by noelpratt2nd at 12:30 PM on February 21, 2020

Best answer: I upped my exercise significantly and kept my calories stable on Zoloft and still gained about 20 lbs (!) In the first month or two and much more after that. I don't buy that people gain weight because of increase in calories or decrease in movement just judging from what happened to several of my friends who also went on ssris (and snris in a few cases), some of whom gained 50+ in short order.

My pcp agrees with me that these drugs have unseen metabolic effects that have nothing to do with (are independent of ) changes in calories in/burned. He's seen substantial weight gain happen to too many weight conscious patients to believe otherwise
posted by shaademaan at 12:48 PM on February 21, 2020 [12 favorites]

Response by poster: Wow! Kinda scary.
posted by noelpratt2nd at 12:56 PM on February 21, 2020 [1 favorite]

I’m not a scientist or a doctor but I don’t think I have to be- it’s common sense that if the medication is sedating (which Mirtazapine is)then your metabolism will slow. Add in the carb cravings of Mirtazapine and some others and wahla- hello 20 pounds. And this can happen in a short time.

I never took lexapro but I have taken Mirtazapine and olanzapine (sp?) which is much more notorious for weight gain... and both really really piled on the pounds. i feel like i was putting on a pound a day! You could literally see the scale moving sometimes.

Life is better for me now, I am mentally well and enjoying my life and reformer Pilates and friendships... I am quite slim, like a size 4 or 6, and feeling fab for a mom of 2 who is getting ready to turn 40.

So don’t worry if you gain weight. Maybe wellbutrin Is a better fit but if not, it will be okay, you will come out the other side and be able to lose the weight. Even if it’s in the realm of 40/50pounds. You wouldn’t have been on mitzapine if it wasn’t serious.
posted by catspajammies at 12:57 PM on February 21, 2020 [1 favorite]

depends on the drug. I saw a weight gain with flovaxamine, but not wellbutrin!
posted by evilmonk at 12:58 PM on February 21, 2020 [3 favorites]

Ps- I say not to worry, but for me gaining a lot of weight gave me the motivation to get myself more balanced so that I didn’t Have to keep taking medication, I went to therapy and also took the meditation, and no junk food and exercise:.. getting out of bed in the morning, getting some sun, showering with nice soap... eventually i started reading again.
posted by catspajammies at 1:05 PM on February 21, 2020 [2 favorites]

Best answer: I'm not a psychiatrist, but I pay an exceptionally qualified one to explain these things to me. His comments:

1) Weight gain while taking SSRIs is a common side effect. However, like most SSRI side effects it varies per person per drug.
2) The research shows that behavioral changes play a large part in weight gain.
3) However, for some people there is clearly a biological part as well.

Leaving behind research for supposition, he points out that the enteric nervous system (stomach, intestine, etc.) is the second largest user of neurotransmitters in the body. In some ways it would be odd if taking SSRIs *didn't* affect it. Research continues.

In any case, there is research that shows that for some people weight gain on SSRIs goes beyond behavioral changes.
posted by Tell Me No Lies at 1:16 PM on February 21, 2020 [3 favorites]

Anecdotally: I had all my life run underweight or very low normal, regardless of how much I ate or exercised, but Mirtazapine puts 15-20 lbs. on me. (I didn't have that experience with other notorious antidepressants, so ¯\_(ツ)_/¯ bodies.)
posted by moira at 2:54 PM on February 21, 2020

Response by poster: I never had weight gain with other sedating meds, like benzos.
posted by noelpratt2nd at 3:18 PM on February 21, 2020

I’m also on Lexapro (for anxiety and IBS-D) and have gained 15 pounds (most of it 4-8 months after starting Lexapro [I had chronic diarrhea, and this is around when that diarrhea stopped]). My PCP mentioned that he’s seen it blunt the feeling of fullness, which jives with my experience- I used to hit a point (at maximal fullness) where the food would be as pleasurable to eat as dirt; I can’t remember the last time that happened.

(Has that lack of fullness effect panned out in studies where they’ve looked at lexapro and amitriptyline for functional dyspepsia? No, it has not. But it’s interesting that th have tried it.)
posted by smangosbubbles at 3:58 PM on February 21, 2020

My PCP told me the same thing as Tell Me No Lies about the enteric nervous system.

In the last year, I've LOST 50 lbs of the weight I gained on Effexor when I switched to Trintellix, with minimal changes in exercise or eating habits. So, yeah, bodies are weird.
posted by SuperSquirrel at 4:33 PM on February 21, 2020

It looks like long-term weight gain likely has to do with the particular serotonin receptors SSRIs interact with, with differences in long- and short-term exposure to the medication. Paroxetine of all the SSRIs has the most different profile. I no longer do much psych, so if it's been more recently studied, someone can give more information. I know that the antipsychotic receptor binding and antagonism properties sites had been much more well studied versus other classes of psychoactive drugs.

I just want to add in a little note of pharm: re: SSRIs. Mirtazapine is not considered one, nor is Wellbutrin. Antipsychotics (Olanzapine etc.) are also not SSRIs and are well known to cause weight gain. Mirtazapine is a different category all together and is often intentionally used in the geriatric population for depression with weight loss and insomnia due to its side effect profile.
posted by cobaltnine at 4:34 PM on February 21, 2020 [4 favorites]

Absolutely right that Olanzapine is not an SSRI. It has a very different mechanism. All the antipsychotics, both first and second generations, are not SSRIs.
I gained weight, about 10 ish pounds, when I started SSRIs. This was primarily because I stopped trying to self medicate with running. Am I little heavier? Yes. Is my overall quality of life much much better? Also yes.
posted by kerf at 4:53 PM on February 21, 2020 [1 favorite]

Response by poster: I had a gf who was on Zyprexa who *lost* weight, but she was also on other stuff. Thanks, all. If I keep gaining on Lexy, I will quit it, it's gotta be fairly unhealthy if you keep on gaining. I can process my depression in other ways (I think).
posted by noelpratt2nd at 4:57 PM on February 21, 2020

Mirtazapine is notorious for causing sugar cravings, to the extent that some people taking Mirtazapine eat whole teaspoons of plain sugar!

But even if your food intake doesn't change on Mirtazapine, Mirtazapine can still cause weight gain.
posted by Murderbot at 8:15 PM on February 21, 2020 [1 favorite]

Best answer: Bupropion [sold under the brand names Wellbutrin and Zyban] is an anti-depressant that is often associated with causing weight LOSS.
posted by Murderbot at 8:33 PM on February 21, 2020 [2 favorites]

I take bupropion and I have not gained weight with it and I've had no problem losing fat and adding muscle with a fitness program while on it. I was on Zoloft in the past, and I didn't gain from that either. You might look into those options (though bup is an SNRI, not SSRI).
posted by Beethoven's Sith at 12:22 PM on February 23, 2020

bup is an SNRI, not an SSRI

Effexor was mentioned above, by SuperSquirrel, in reference to their having gained weight while taking it.

Like buproprion, Effexor (generic name: venlafaxine), is a serotonin norepinephrine reuptake inhibitor, or an SNRI. It is not an SSRI (short for selective serotonin reuptake inhibitor). I was prescribed it after a couple of SSRIs didn't work for me (Prozac, I know, and Paxil, I think -- this was about 20 years ago.)

I haven't gained weight on Effexor. (YMMV, obvs.) It has worked for me, though not without obnoxious side effects (I have to take it at the same time every day or risk feeling like I have vertigo.)
posted by virago at 7:31 PM on February 23, 2020