Phentermine

About Phentermine: its advantages, precautions, how to take, results of therapy

Phentermine is a popular weight loss drug, chemically related to amphetamines, which was approved by the Food and Drug Administration in the US in 1959. As it is so closely related to amphetamines, the drug is potentially extremely addictive and regarded as a controlled substance under US law. Phentermine is also named internationally under the Convention on Psychotropic Substances. It is available on prescription only in the US.

Phentermine is sold under a number of different trade names, including Ionamin and Adipex-P, and also under its own name. It was temporarily sold as Fastin, but this was voluntarily removed from the market in 1998.

Phentermine works with neurotransmitters to block the hunger message before it reaches the brain. It does this by encouraging the production of dopamine, adrenalin and noradrenaline, which then act upon the central nervous system. These hormones stimulate the 'fight of flight' response which takes precedent over any feelings of hunger. Triggering these neurotransmitters thus prevents the hunger signal from reaching the brain and setting off a feeling of hunger.

Fen-Phen (a compound of fenfluramine/dexfenfluramine and phentermine) was synthesised for public use in the 90s, and initially appeared to be more effective than any other drug or dieting and exercise – with no serious side-effects. It quickly became apparent, however, that this was not the case and that the drug dramatically increased the likelihood of developing heart valve disease. The FDA asked for the drug to be removed from the market, but maintained its original decision of phentermine itself.