Adipex vs. Fastin

Phentermine is a stimulant that can help obese patients to lose weight. Originally, Adipex and Fastin were two brand names for the generic drug phentermine and had similar effects on weight loss. However, Fastin was taken off the market in 1998 and re-released 10 years later with a formulation that no longer contains phentermine. Both drugs help weight loss by suppressing appetite, and Fastin also claims to give you more energy to work out and to improve the body's ability to burn fat.

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Adipex-P is a name-brand version of the generic drug phentermine manufactured by Gate Pharmaceuticals, and is available by prescription only. One pill contains 37.5 mg of phentermine hydrochloride, which is equivalent to 30 mg of phentermine. Phentermine is a stimulant that suppresses appetite, and is prescribed for obese patients as part of a program that includes exercise and a healthy diet. It should not be taken by patients with heart disease, uncontrolled high blood pressure, glaucoma or certain other serious medical conditions. Adipex-P is similar to an amphetamine, and patients can become physically addicted to it.

The Old Fastin

Fastin was originally another brand name for the drug phentermine, this one manufactured by King Pharmaceuticals for Smith Kline Beecham and was also available by prescription only. In December 1998, Fastin was removed from the market at the order of U.S. Food and Drug Administration. Other brands of phentermine, including Adipex-P and Ionamin, as well as a generic brand, were still being sold.

The New Fastin

In late 2007, Hi Tech Pharmaceuticals announced it had bought the rights to the Fastin name and would be re-releasing the drug as a non-prescription weight loss supplement. The new Fastin was released in January 2008. The main ingredient in the new Fastin is phenylethylamine, not phentermine, and it is marketed as an "herbal stimulant." Fastin contains eight other active ingredients, including caffeine, all of which the manufacturer claims promote weight loss. Hi Tech Pharmaceuticals warns Fastin should not be used by people under 18, and should not be taken with other sources of caffeine or with other weight loss drugs, including phentermine.


Any weight loss program should be conducted under the supervision of a doctor, even if it involves a non-prescription diet aid such as Fastin. Your doctor will be the best judge of which weight loss supplement, if any, is best for you. Adipex-P and Fastin will be most effective as part of a comprehensive and long-term program of exercise, healthy diet and behavior modification. Do not take more diet pills than recommended, as this will not improve your results and may endanger your health. Healthy and permanent weight loss requires patience. It took you a long time to put on the weight, so it will take a long time to take it off.