Phentermine
"I am 25 years old.  I am 5'11, and weighed 244lbs. Have used phentermine for about 4 months and have lost 40 pounds. I tried multiple diets and nothing worked. I lost about 6 pounds my first 2 weeks and then the next 3-4 pound a week on the next few weeks.  For me, the best way to take it was 1 hour before breakfast.  When I started to notice that my weight loss was slowing down, I would stop taking the pills for 2 weeks, and started them again.  This helps to get it going again, just be strict not to lose the healthy eating and exercise in that time.  Phentermine caused me some insomnia in the beginning but then it stopped.  Causes some dryness of the mouth but it's good because it makes you drink more water, which is great!"