Wow. I am surprised to see how many children are being put on this medication! I am surprised because the label on my bottle says specifically for adults 15 YEARS of age and older... As for my experience with Singulair, I have been taking this medication off and on for about a year now. I was put on it for severe allergies as everything else I tried did not work for me. (Claritin, Allegra, Flonase, Veramyst, etc) The first month or so on Singular I noticed that I would get severe headaches in the afternoon about the same time everyday. I would have to take aspirin just to make it through the every workday. These headaches eventually tapered off even though I will occasionally get a headache. The Singulair definitely helped me with my allergy symptoms and when I would go off, I would usually end up with a cold or sinusitis.