Hi.. Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concerns.. As per your complain lip quiver can occur in case if you have high thyroid hormone levels and in case if you have got an increase in dose of Synthyroid, it might be a cause for quivering of lips.. Other causes that can also commonly cause quiver of lips are Vitamin B12 and calcium deficiency, potassium deficiency, traumatic injury or inflammation of facial nerve that supplies muscles of face,anxiety and panic attacks, nerve inflammation and infection caused by viruses etc.. I would suggest you to first of all consult your treating Physician and get evaluated and a thorough clinical evaluation can help in diagnosis.. In case if increased dose is ruled out as the culprit either you will be advised to wait and watch so that the body gets adapted to the increased dose..In case if still the problem persists the dose has to be reduced.. In case if increased dose is not the cause then you will be advised to get investigations done like MRI, CT Scan, Nerve conduction studies, Electromyogram etc to rule out the exact cause of the problem and treat you accordingly.. You can be advised to take multivitamins along with calcium and potassium supplements.. You can do warm compresses over the lips. You can also do breathing exercises along with meditation to keep stress minimal.. Hope this information helps.. Thanks and regards. Dr.Honey Nandwani Arora.