If you want to do it in a healthy way and keep it off try a nutrient dense diet of fruits, veggies, beans, nuts, and seeds. Eliminate all processed foods and sugar. Try visiting http://www.drfuhrman.com/ for recipes and more information. I lost 20 lbs my first month. It slowed down after that and I lost about 50 lbs in about 4 1/2 months. It's healthy and will make you feel the best you have in your life.
Apple Cidar Vinegar Pills and Cayenne Fruit pills everytime you eat. Eat a lot of veggies & fruit. Also, do not eat refined carbs, stick with whole wheat. Odwalla Juice is great as a snack.
Are you actually overweight or do you just want to be skinny? 15 pounds in a month is too much to do safely. Safe weight loss is 1-2 pounds/week.
What have you tried, so far?