"i lost 10lbs in one month from taking alli. and 17 all together after 3 months. it works without a doubt! unfortunately for me, it also had a bad side effect- considering that my lifestyle and circumstances haven&#039;t changed i can narrow it down to alli: i became extremely depressed. it blocks out all fat including good fat that your body needs. so, after speaking to my doctor, i sacrificed my weight loss for my mental health, i stopped taking the drug and now i am back to my regular old self after 6 weeks. depression is a terrible.  i will never take alli again or any fat blocking drug. right now i&#039;m doing it the hard way: portion control and plenty of water. i will also add that was my first time ever that i suffered depression"