Never, even if you are old enough to take them they'll always screw something up and can give you harmful skin diseases, and mess up your immune system. Plus, they'll give you ALOT of loose skin.

The only weight loss pill that works is that alli and all you do is sit on the bathroom. I tried diet pills they don't work. Eat a little under 1500 calories a day, exercise five times a week doing strength training and aerobic exercise. If you are under 18 you shouldn't worry about diet pills.

18-21
No sooner! Unless they're doctor-prescribed, you can kill yourself with them. They're in dosages meant to fit a fully adult body, and having that many toxins in your body any younger than 18...you might as well suck down a keg of beer or start smoking crack.
Seriously, if you're under 18, don't even think about it.

18. Don't listen to the people that say that all you do is sit in the bathroom with ALLI. You don't. My mom takes it still after her lap band and loves it. She also took Phen Phen and no one died from it.

it depends on the pill. ALL supplements say they are not for ages 17 and under, but you can take hoodia before you're 18. Anything but that, wait til you are 18. Eat healthy and exercise.

Weight loss pills are no good at any age.
Remember phen-phen? Or however you spell it. That was doctor-prescribed, and people died from it. Try diet + exercise.

18. They can be harmful for a person who is not done growing yet!

um, weight loss pills aren't recomended...try hard work...