It is within this time when an overweight person is being introduced to phentermine without prescription, the best pill for diet control rather the best appetite suppressant available in the market nowadays. Phentermine was introduced in the market of US during the 1950s with some other diet control pills such as aide and fenflueramine. There is a similarity between the drug that that is used in treating people having drug addiction and the phentermine, hence this drug is sold under high medical supervision. The phentermine works with the sensitive parts and thus it helps them to arise, which will result in the feeling of fullness and satiety of stomach. The neurotransmitters in the brain combine with the phentermine and help the brain to release a chemical known as catecholamine, which bars the hunger signals going to the brain. This restriction of sending hunger signals causes loss of the desire to have food as the brain is barred from getting the hunger signals coming from the abdomen. The hypothalamus region of the brain is the working area of the phentermine. In the brain, the area that is responsible for controlling appetite is the hypothalamus. Therefore, phentermine is a response to all those who have gain unnecessary weight because of overeating.