Wellbutrin XL and Wellbutrin SR are different formulations of the antidepressant bupropion. Both Wellbutrin XL and Wellbutrin SR may cause weight gain or weight loss, but weight loss is more common. Bupropion (Wellbutrin) treats depression. It helps regulate your mood by increasing norepinephrine and dopamine hormones in your brain. Wellbutrin (bupropion) is used to treat major depressive disorder and seasonal affective disorder. Includes Wellbutrin side effects, interactions and indications. Bupropion is used to treat major depressive disorder (MDD) and to prevent seasonal affective disorder (SAD), which is sometimes called autumn-winter seasonal depression. It is also used as part of a support program to help people stop smoking. Bupropion is sold under different brand names. It is approved for the treatment of major depressive disorder (MDD), seasonal affective disorder (SAD), and to help people quit smoking (smoking cessation). Symptoms of depression include: SAD is a type of depression that occurs mainly during the autumn-winter season. Wellbutrin is used to treat major depressive disorder and seasonal affective disorder. Common side effects of Wellbutrin include headaches, dry mouth, nausea, dizziness, insomnia, and constipation. Call your doctor if you experience serious side effects such as difficulty breathing or swelling. Find patient medical information for Bupropion (Wellbutrin, Zyban, and others) on WebMD including its uses, side effects and safety, interactions, pictures, warnings, and user ratings Wellbutrin (bupropion) used to treat the symptoms of major depression and seasonal affective disorder. Learn side effects, dosage, drug interactions, warnings, patient labeling, reviews, and more. The FDA investigated these complaints and concluded that Budeprion XL is equivalent to Wellbutrin XL regarding bioavailability of bupropion and its main active metabolite hydroxybupropion. What is Wellbutrin? Wellbutrin is the brand name for bupropion and the active ingredient in Wellbutrin is bupropion hydrochloride (bupropion HCl). It’s commonly used to treat major depression and seasonal affective disorder or SAD. It’s also used to aid in smoking cessation.