Lamictal's smallest denomination is 25 mg. You could go down to 75 mg to see if the side effect goes away. Maybe 75 mg is your sweet spot. rxlist.com does list this side effect to lamictal. many side effects are dose dependent, which is why titrating down may make sense for you. As a separate note, if you felt like yourself in a good way on 50 mg, maybe you should stay on 50 mg. Does your prescriber observe you clinically and listen to your self-observations? dosage guidelines are on thing and clinical findings are another thing. I would definitely try 75 mg now. If you do not have 25 mg pills, you can cut a 50 mg in half.