Other side effects include: abdominal pain, dyspepsia, increased serum alanine aminotransferase, orthostatic hypotension, pharyngitis, weight gain, and tachycardia. See below for a comprehensive list of adverse effects. Unfortunately these side effects can be too debilitating to overcome, and lead to inevitable weight gain. Slows metabolism : Even if you maintained the same diet and exercise patterns pre-drug that you did while taking Seroquel, you’d probably still gain some weight. One of the most commonly reported side effects is weight gain.4 Over time, excess weight can harm the heart, lungs, stomach, liver, pancreas, and other organs. While many people gain weight while taking Seroquel as prescribed, the result isn’t inevitable. Some are able to remain within a healthy weight by following their doctors’ orders regarding a healthy balance of diet and exercise. Side effects can occur with the use of Seroquel, and weight gain has been reported as one of them. In fact, a small amount of weight gain is typical when taking the drug. Seroquel and Seroquel XR (quetiapine) is an antipsychotic drug used to treat bipolar disorder and schizophrenia. Common side effects include agitation, headache, and upset stomach. Serious side effects include suicidal thoughts, prolonged erection, and stroke. Pregnancy and breastfeeding safety information is provided. Our Seroquel Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication. This is not a complete list of side effects and others may occur. However, a study published in European Eating Disorders Review in 2012 found that Seroquel did not help people with anorexia gain weight, nor did it help ease their symptoms of anxiety or depression. If you or a loved one is taking Seroquel or considering doing so, you should learn all you need to know about Seroquel side effects. Some patients gain weight and feel drowsy; others may have trouble sleeping or serious stomach problems. On the other hand, some patients experience only the stabilizing benefits of this drug. I also take seroquel same dose as you and have taken up to 900mgs. You are not putting on the weight by taking the pill, a side effect of this medication which is very common is increased appetite, so that is why you are 8 Ibs above your actual weight.