I am an 18 year old girl I weigh 115 lbs I am 4'11 and just started taking 500 mg L-Carnitine supplements daily to loose 15 lbs how long will this take and is this harmful to a girl my size?

I am the same height as you. I weighed 105 and was fine. You are ten pounds overweight unless you are very small boned. The L-carnitine would take months to work to lose a mere ten pounds. Decrease your portions. Quit eating junk foods. Avoid sugary drinks and pops. See your pediatrician for a proper diet and amount of exercise. If you your parents and other adults say you do not have a flabby fat body and you fear food than tell that to your pediatrician. You don't want to fall into the trap of anorexia nervosa. A proper diet pattern and a little more exercise will result in a two pound a week loss. So it should only take five weeks to lose the weight or perhaps faster since teens, even the older teens lose weight faster. Don't depend on pills of any type to lose weight. The dietary improvements and increase in exercise must be done.