Phentermine is a prescription medication used by a type of weight loss medicine that helps to reduce fat very fast. It is the best because it controls our appetite on a daily basis. Phentermine the weight loss tablet is in the form of Phentermine 15 mg, Phentermine 30mg, and Phentermine 37.5 mg. Take directly by mouth, normally before breakfast or 1 to 2 hours after breakfast. Avoid this medication, if you are pregnant, in case you start using consulate with a health professor immediately.