Will lexapro make you gain weight?

I've never heard of an anti-depressant/anxiety med increasing weight. Their methods of action are typically neurological and as far as I know do not generally affect thyroid function to any significant degree. Just as many things, they may increase you appetite (this is why-to a certain extent-people are claiming sugar substitutes are bad because they increase weight), but as far as I'm aware there's no direct correlation. It looks like trycyclic antidepressants may cause weight gain, but anymore these are rarely used. Interesting short read (https://www.medicalnewstoday.com/articles/319527#types-of-antidepressants-that-may-cause-weight-gain).

You are talking about a ~5 month stretch; gaining 10lbs in that time span is certainly not unheard of. If you weren't/aren't properly tracking intake and weighing on a regular basis (which it sounds like you weren't) I'd guess you were eating above your TDEE on a consistent basis, so the weight gain was probably subtle and over time.

There tend to be 3 mechanisms for medication-mediated weight gain:

1. Appetite increase. (Which will be observed if carefully calorie counting.)
2. Energy level decrease/fatigue. (Moving less, possibly in subtle and largely-unnoticed ways, but the effect can still add up - even fidgeting vs. not can vary calorie expenditure in the low hundreds of calories per day.)
3. Water retention. If there's a higher average level of water retention than before the medication, it will show up on the scale, but it isn't fat.

Are those absolutely the only mechanisms? I don't know. But they're important and common ones. I think being analytical about those can give us some insights - or at least that's been my personal experience.

If you weighed 10 pounds less around 5 months ago, that would be approximately 2 pounds of gain per month. If it's all fat (which is not assured), that would imply a calorie surplus (above maintenance calories) of about 250 calories, from either eating more or moving less, or a combination.

That's about a peanut butter sandwich worth of food, so not much. On the movement side, for the 129 pound body, it'd be around 2.5 hours of very slow walking (2mph) or equivalent other movement. (It's roughly close to the range of the difference that research posits between a fidgety person and a placid person of the same body weight, per day.) Small changes add up. Obviously, if any of it is water retention, that's a whole different question.

nooshi713 wrote: »

Yes. Many antidepressants cause weight gain.

But not directly though, right? Through the reasons mentioned above, like increasing your appetite, fatigue causing you to move less, etc. So you still have the possibility to control and manage it if you balance your calorie intake and expenditure.

beccali2019 wrote: »

AnnPT77 wrote: »

There tend to be 3 mechanisms for medication-mediated weight gain:

1. Appetite increase. (Which will be observed if carefully calorie counting.)
2. Energy level decrease/fatigue. (Moving less, possibly in subtle and largely-unnoticed ways, but the effect can still add up - even fidgeting vs. not can vary calorie expenditure in the low hundreds of calories per day.)
3. Water retention. If there's a higher average level of water retention than before the medication, it will show up on the scale, but it isn't fat.

Are those absolutely the only mechanisms? I don't know. But they're important and common ones. I think being analytical about those can give us some insights - or at least that's been my personal experience.

If you weighed 10 pounds less around 5 months ago, that would be approximately 2 pounds of gain per month. If it's all fat (which is not assured), that would imply a calorie surplus (above maintenance calories) of about 250 calories, from either eating more or moving less, or a combination.

That's about a peanut butter sandwich worth of food, so not much. On the movement side, for the 129 pound body, it'd be around 2.5 hours of very slow walking (2mph) or equivalent other movement. (It's roughly close to the range of the difference that research posits between a fidgety person and a placid person of the same body weight, per day.) Small changes add up. Obviously, if any of it is water retention, that's a whole different question.

Thank you for such a detailed explanation.

1. I did not closely track calories. I remember the first couple weeks when I first started taking lexapro I experienced a lot stomach upset. I felt I had to use food to decrease that uncomfortable feeling. I actually woke up in the middle of night for like over one week straight to eat, like tuna or nonfat greek yogurt… basically pure proteins, but still, I went right back to sleep and that’s extra calories.

2. Excellent point. Lexapro makes me so low energy!!! I used to be able to work out for an hour straight doing weight training but now even a 30min workout will beat me. And overall I’m way easier to get tired and being lazy. In the first few days of taking lexapro, I literally feel like I was walking on cloud everyday and could fall asleep when I’m walking. For me, even 2.5mg lexapro worked like a sedative that I simply didn’t have extra energy to be anxious in the first couple weeks.

3. How can I tell if it’s water retention or not? Someday I feel myself extra puffy and other days I can feel my bones more easily and tighter skin (I usually use my shoulder area to test), and this is maybe a week apart? Overall I eat a moderate or low sodium diet. Is sodium the only factor deciding water retention? For ladies, besides menstrual cycle and birth control pills (which I don’t take anything besides lexapro now), any other factor?

There are so, so many things that can influence water weight, and it can be hard to tell (short of versions so extreme as to be medical crisis) how much is there. Keep in mind that our bodies can be 60%+ water, so some substantial (multi-pound) fluctuations are possible even in a healthy person.

In case you haven't read it, this article is a very good run down on many of the sources/cause of water weight fluctuations:

https://physiqonomics.com/the-weird-and-highly-annoying-world-of-scale-weight-and-fluctuations

What we often say here is that if you haven't changed calorie intake or activity level enough to explain a weight change, it pretty much has to be water weight (or non-average amount of digestive contents on their way to becoming waste), especially if the changes have been relatively quick. However, since you haven't been calorie counting, that's a harder thing for you to figure out.

About all one can do about water weight is stay well hydrated (no reason to overdo), maybe think about electrolyte balance, manage stress . . . and wait it out. It's not fat, so IMO, once I'm pretty sure that's what it is, my aim is not to worry about it (stress can cause water retention, right? 😉), let it run its course. I get that that's not easy: I think I have some going on now, from resuming strength training after a hiatus, and it's on top of some water/fat gain from holiday eating choices . . . 🙄.

beccali2019 wrote: »

joowelz wrote: »

Yes. 100% it will. Most do. You will have to be extra religious about controlling calorie intake. The problem with anti depressants is they rev up your appetite especially in the first few weeks. Then you get into a habit of eating more. I've been on these meds 4 times in my life and gained 10 lbs - 20 lbs with each kind. I am off meds now and it has taken me 2 years to wean off and lose the weight.

@jooseltz, yes this is my second time on lexapro. The first time I was in early 20s and it didn’t impact my weight at all, probably because I was young and had a much higher metabolism and I moved a lot when I was in college. But now I’m in my early 30s, and I noticed the feeling in stomach this time. It was so weird like I was hungry all the time and needed to eat but I couldn’t eat much when I actually started eating. I was aware of “rumors” of antidepressants would bring up your weight and I was actually going to be extra careful. But with the anxiety back then I didn’t have extra energy to pay attention to these things at all. A little regretted now…

For what it's worth, there's some recent research suggesting that metabolic decline with age isn't a big deal, in the roughly age 20 to 60 age range.

https://community.myfitnesspal.com/en/home/leaving?allowTrusted=1&target=https://pubmed.ncbi.nlm.nih.gov/34385400/

I'm around twice your age (66). What frequently does happen between our 20s and our 30s are pretty big changes in daily life, and those can have a big impact on calorie expenditure. When I was 20, I was in college, walking or biking back and forth across campus (often over a mile at a time, in the 20 minutes between classes) several times daily, and working a very physical job (industrial-scale dishwashing in an 800-person dorm, so slinging big trays of dishes and cutlery around at speed), living upstairs in a dorm with lots of stairs and no elevators, then doing things like dancing and playing active games in off hours for fun. By 30, I was in a desk job, driving to work, coming home, doing a little cooking/housework, maybe reading or watching TV. Guess what happened? Yup, weight gain. Metabolic? Nah. 😉 Your situation may differ, but I think variations on my scenario are pretty common.

It wouldn't be unusual to have a different digestive reaction to a medication a decade or so later, for a variety of reasons. The context is likely to have changed (background diet, for example), our stress levels have changed, we may have different health conditions going on, and more.

I hope your recent dosage change will give you a better balance of symptomatic relief alongside reduced side effects. Let us know, OK? Believe it or not, we strangers here do care - it's always interesting, and potentially useful to others, to know how these things work out.

Best wishes!