... December and am only on 25 mg but will be increasing to 50 mg this weekend. I also feel like I am losing weight since I started Lamictal which may be causing some of the weakness. I am not sure what my final dosage will be. I am on Lamictal for anxiety and depression. Lamictal was prescribed due to the low amount of side effects and that is one of the reasons I agreed to take it. I worried about the rash and was happy that did not happen but I am not sure if the weakness in my legs is from the Lamictal or my anxiety