Phentermine For Weight Loss

by Gal Trieu
July 13th 2008

Obesity is a chronic disease that affects many people and often requires medical treatment to promote and sustain weight loss. Phentermine, a prescription medication, can be used to assist with the battle of obesity. While most side effects of Phentermine are mild, serious complications involving Phentermine have been reported. Phentermine should only be used by patients who are at increased medical risk because of their obesity. Phentermine should not be used for "cosmetic" weight loss.

Phentermine is a tablet that is used in the short-term management of obesity. It comes in various colours, in tablet or capsule form and in strengths of 15, 30 and 37.5 milligram.

Phentermine works by suppressing appetite via a central mechanism in the brain. Use of Phentermine in combination with other appetite suppressant medicine is generally not recommended.

Phentermine is an effective form of therapy for obese patients who need to lose weight to decrease diseases associated with obesity. The magnitude of the weight loss through using Phentermine will depend on the degree of caloric restriction and the use of a graded exercise program.

Phentermine should be used as a short term drug to help patients to start losing weight while the patient is undergoing permanent long term changes in their attitude towards food and exercise. The body starts to build up a resistance to the effects of Phentermine after a few weeks of treatment, by which time the patient should be well on their way to a new lifestyle and ready to stop taking Phentermine while continuing to maintain a healthy weight on their own. Taking Phentermine is not a substitute for proper diet. For maximum effect, Phentermine must be used in conjunction with a diet and exercise program.

Phentermine is the generic name of the drug. It is distributed under different brand names including ADIPEX-P and IONAMIN. There are many popular brand names of Phentermine. In terms of fighting obesity, they are all considered clinically equivalent in producing weight loss. Phentermine comes in immediate release or time-release formulas. Immediate release Phentermine pills enter the blood stream as soon as they are taken and time-release Phentermine capsules release their medication into the body over an extended period of time, generally 8 or 12 hours.

Phentermine does have some reported side effects. These include:


Blurred vision, dry mouth, sleeplessness, irritability, stomach upset or constipation may occur the first few days as your body adjusts to the medication. Other adverse events include central nervous system effects, gastrointestinal disturbances, and changes in libido. Alcohol can increase unwanted side effects of dizziness.


Chest pain, pounding heart, difficulty urinating, breathing difficulties or swelling while taking this medication


Primary pulmonary hypertension (PPH) and cardiac valvular disease have been reported in patients receiving a combination of Phentermine and Fenfluramine (Phen-fen) or dexfenfluramine. The possibility of an association between PPH and the use of Phentermine alone cannot be ruled out.

Since Phentermine has a similar chemical structure to amphetamines, taking Phentermine may cause a positive result in urine screening tests for amphetamines.

After a patient ceases taking Phentermine, their body may need time to adjust. The length of time this takes depends on the amount of Phentermine they were using and how long they were using Phentermine.

Phentermine may be appropriate for carefully selected patients who are at significant medical risk because of their obesity. Phentermine is not recommended for use by people who are only mildly overweight unless they have health problems that are made worse by their weight. Phentermine should not be used only to improve appearance. For most severely obese people, achieving an "ideal body weight" is both unrealistic and unnecessary to improve their health and reduce their risk for disease. Most patients should not expect to reach an ideal body weight using the currently available medications. A modest weight loss of 5 to 10 percent of the patient’s starting body weight can improve their health and reduce their risk factors for disease. Use of Phentermine for cosmetic purposes is not appropriate.

It is important to remember the use of Phentermine alone cannot treat obesity. Phentermine should be combined with a healthy lifestyle including physical activity and improved diet to lose and maintain weight successfully over the long term. For short term use, Phentermine has been widely successful in achieving weight loss and reducing the risks of medical problems associated with obesity.