Oh, my goodness! I have been wondering why all of the weight gain! I exercised like a fool and could not lose weight. I have been taking singulair for years. I stopped for a bit (about a month) and began to take it again about two weeks ago. I am now experiencing severe tinnitis (ringinig in the ears) and MORE weight gain. I have severe dizziness and nausea! I have been bruising easily ever since I began takig it years ago! I get pains in my legs, as well. I am stopping as of TONIGHT!!! Thank you to you all for sharing your side effects. I now understand more clearly where all of this weird stuff is coming from!! Be blessed!