I am a 45 year old Female and this is my third refill & attempt to try singular as it was wonderful for my asthma and allergies. I actually threw the 1st 2 bottles out-as my side affects were horrendous. Headaches, sick stomach, exhausted, horrible mood swings, depressed, itching, finger joint aches, could not function and focus, I was desperate and tried it again and took 1/2 a pill instead of whole - it did not seem to help my allergies and therefore not enough to create as horrible poisoness feelings of the side effects. I just vomitted again after having a horrible exhausting day. I do not think this drug is worth the side effects. There are other sites that talk about Singulair - and no we are not crazy.