Hi, Advil is a potent drug to get relief from pain. It does have some dangerous side effects but not the one you are mentioning i.e shaking of legs. Get emergency medical help if you have chest pain, weakness, shortness of breath, slurred speech, or problems with vision or balance. Advil may also cause serious effects on the stomach or intestines, including bleeding or perforation (forming of a hole). These conditions can be fatal and can occur without warning while you are taking Advil, especially in older adults. Call your doctor at once if you have symptoms of stomach bleeding such as black, bloody, or tarry stools, or coughing up blood or vomit that looks like coffee grounds. Do not take more of Advil than is recommended. An overdose of ibuprofen can cause damage to your stomach or intestines. Use only the smallest amount of Advil needed to get relief from your pain, swelling, or fever. As for the leg shaking, it s not due to advil. If it happens again, I d advice you to visit your treating doctor and get a check up. Hope your query has been solved. Feel free to ask for any doubts. Regards, Dr. Sridhar Reddy