I started Phen back in October, and I started losing the weight the first week.I changed my complete diet, and work out 60-90 minutes 6 days a week. How Does Phentermine Work? Contrary to what some people believe, phentermine is not a miracle pill which can help you lose weight without exercise or watching what you eat. Like other prescription weight-loss drugs, phentermine is intended to be used as part of an overall weight-loss plan. It is indicated for people who are obese, and who have failed to lose enough weight with diet and exercise alone — not for people who want to lose just a few pounds. How Does Adipex Work For Weight Loss? In a basic explanation, phentermine pills are used like a stimulant to the central nervous system – it helps to suppress appetite and increase energy, making it somewhat easier to reduce caloric intake and boost the metabolism to burn fat cells. phentermine stimulates the release of brain chemicals that will manipulate your mind to curb your appetite, so you feel full and eat less. your doctor may prescribe this under the names adipex or supr Yes, Phentermine for weight loss does work. Studies and Phentermine before and after pictures have shown individuals using the medications have lost weight. But, the Phentermine average weight loss may vary and the company states that the medication is only for short-term use. Phentermine is a prescription weight loss medication. It was approved by the FDA in 1959 for short-term use of up to 12 weeks for people older than 16 (). The fast weight-loss drug is the top prescribed drug by obesity treatment specialists, according to an article published in the Yonsei Medical Journal. While phentermine is only approved for short-term use for a period of 12 weeks or less, the potentially severe side effects are noticeable upon primary usage. The anti-obesity drug can help you turn from fat to fit in a short interval of time. For Obesity: I'm on my 5th month of Phentermine for weight loss. I was originally prescribed it for 3 months, but since I'm doing well with NO side effects, my doc gave me the option of taking it for up to 6 months. Lifestyle changes can make a significant difference to boost phentermine, but it is also important to remember that just because weight loss slows does not mean that phentermine is not working. Medically, a moderate drop of 1-2 pounds per week is considered healthy weight loss [ 3 ].