Does 15mg of Mirtazapine cause weight gain?

In this blog post, we will discuss Mirtazapine-induced weight gain. We will also discuss some research studies and what to do if you’re gaining weight while taking Mirtazapine.

Does 15mg of Mirtazapine cause weight gain?

Yes, Mirtazapine can cause weight gain regardless of the dosage strength being used. This is one of the listed side effects of this antidepressant, and it can also increase cholesterol levels – making it unsuitable for a certain population (1). 

However, it is important to note that antidepressants don’t affect everyone in the exact same way. Some people may not experience this side effect. 

If you are taking 15mg of Mirtazapine and are observing unusual weight gain without any significant changes in your diet, please reach out to your healthcare provider. 

What does research suggest?

Several research studies have linked Mirtazapine to weight gain. A recent research study included healthy men taking Mirtazapine for severe days, which led to several changes. Triglyceride levels increased, as did the ratio of triglycerides to HDL cholesterol. 

Some men also experienced weight gain (2). In another study involving seven women, Mirtazapine was administered for 6 weeks – while a control group of seven healthy women was observed (3). 

The women taking Mirtazapine saw an increase in body weight and fat mass but didn’t experience significant changes in insulin, glucose, or insulin resistance. 

Leptin concentrations also increased in the Mirtazapine group, while the control group’s parameters remained stable (3). This suggests that Mirtazapine treatment can lead to weight gain and higher leptin levels, but it doesn’t seem to affect glucose regulation. 

Some other research studies have shown an increase in insulin levels after Mirtazapine administration, combined with increased C-peptide and sugar cravings (4). This indicates that Mirtazapine can cause weight loss by triggering unusual cravings – which can also lead to insulin resistance with time.

What factors can contribute to Mirtazapine-induced weight gain?

Several factors can contribute to weight gain induced by Mirtazapine. Firstly, lifestyle plays a significant role. Factors such as diet and exercise can influence weight gain. 

If someone’s diet consists of high-calorie, low-nutrient foods and they have a sedentary lifestyle, it can exacerbate weight gain. Lack of physical activity can also contribute to this. Furthermore, insufficient sleep can be a contributing factor (5). 

Poor sleep patterns can disrupt hormonal balance, leading to increased appetite and potential weight gain. Additionally, underlying health conditions can make it easier for individuals to gain weight, as these conditions might affect metabolism and energy expenditure (5). 

It is also important to know that individuals have different body tendencies when it comes to weight gain. Some people may be genetically predisposed to gain weight more rapidly than others when exposed to medications like Mirtazapine. 

All these factors can interact and contribute to the weight gain experienced with Mirtazapine.

What to do if Mirtazapine is making you gain weight?

If you find that Mirtazapine is causing unwanted weight gain, it’s essential to report it to your healthcare provider. Your doctor can evaluate your situation and discuss some options. 

Some doctors may consider adjusting the dosage to help your body adapt better to the medication while minimizing weight gain. Others might explore alternative antidepressants that have a lower likelihood of causing weight gain. 

It’s essential not to make changes to your medication regimen without professional guidance, as this can have disturbing consequences. 

It is also important to keep taking Mirtazapine just as directed by your doctor and avoid anything that may interfere with the medication or your body’s ability to recover from depression, like excessive use of alcohol or substance abuse. 


In this article, we have discussed Mirtazapine-induced weight gain. We have also discussed research studies, some factors that may contribute to weight gain, and what one should do if this side effect occurs. 

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Jilani TN, Gibbons JR, Faizy RM, Saadabadi A. Mirtazapine. 2022 Sep 7. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan–. PMID: 30085601.


Lechner K, Heel S, Uhr M, Dose T, Holsboer F, Lucae S, Schaaf L, Fulda S, Kloiber S, Hennings JM. Weight-gain independent effect of mirtazapine on fasting plasma lipids in healthy men. Naunyn Schmiedebergs Arch Pharmacol. 2023 Sep;396(9):1999-2008. doi: 10.1007/s00210-023-02448-y. Epub 2023 Mar 9. PMID: 36890393; PMCID: PMC10409833.


Laimer M, Kramer-Reinstadler K, Rauchenzauner M, Lechner-Schoner T, Strauss R, Engl J, Deisenhammer EA, Hinterhuber H, Patsch JR, Ebenbichler CF. Effect of mirtazapine treatment on body composition and metabolism. J Clin Psychiatry. 2006 Mar;67(3):421-4. doi: 10.4088/jcp.v67n0313. PMID: 16649829.


Hennings JM, Heel S, Lechner K, Uhr M, Dose T, Schaaf L, Holsboer F, Lucae S, Fulda S, Kloiber S. Effect of mirtazapine on metabolism and energy substrate partitioning in healthy men. JCI Insight. 2019 Jan 10;4(1):e123786. doi: 10.1172/jci.insight.123786. PMID: 30626746; PMCID: PMC6485362.


Piaggi P. Metabolic Determinants of Weight Gain in Humans. Obesity (Silver Spring). 2019 May;27(5):691-699. doi: 10.1002/oby.22456. PMID: 31012296; PMCID: PMC6481299.

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