If depression led to weight loss, then weight gain while taking Zoloft may be due to improvement of depression symptoms. But if your weight gain is unwanted, you can prevent it. Remember that adults typically gain weight every year, even if they are not taking medications. Welcome Veaze, I'm sorry you are having such a time. I did take Zoloft for over a year, and did gain weight.. but I REALLY was eating too much. Can Sertraline cause Weight Gain? Weight Gain is a known side effect of Sertraline. Complete analysis from patient reviews and trusted online health resources, including first-hand experiences. If you have gained weight from Zoloft, feel free to share how much you gained, the dosage you took, and the time span over which you took the drug. Also feel free to discuss what you think caused the weight gain and if there were any other factors that may have also contributed. Zoloft is the brand name of sertraline, an antidepressant used to treat major depressive disorders. Zoloft is in a class of antidepressants known as selective serotonin reuptake inhibitors (SSRIs). Hello alisha29! Sertraline can cause weight gain as well as other SSDRI S. I did gain weight during the first year, which was around 1990. I have not met anyone who has not gained weight on Zoloft. You probably aren't taking enough of the Zoloft yet. You may need an increase In the dose. Almost all antidepressants have the side effect of weight of gain except for wellbutrin. Your doctor can also give you some tips for preventing weight gain while on antidepressant therapy. Medically reviewed by Timothy J. Legg, PhD, CRNP on June 25, 2018 — Written by Jacquelyn Cafasso I started taking zoloft 50mg per day 3 days ago. I was prescribed zoloft for depression and anorexia, I want to know if it can make you gain weight..