Holistic forms of treatment, such as functional medicine, are the most effective approach to losing weight effectively. People who are attempting to lose weight frequently resort to diet pills and potions that make unfulfillable promises out of frustration or even desperation for quick results. A prescription appetite suppressant, phentermine is only suggested for morbidly obese patients and is only permitted for short-term use. In addition to impaired vision, dry mouth, insomnia, irritability, and constipation, it can also elevate blood pressure and pulse rate.