• The dosage of Phentermine varies depending on factors such as the individual's weight loss goals, medical history, and response to treatment. 
• It is usually taken orally in the form of tablets or capsules, typically once daily in the morning before breakfast or one to two hours after breakfast. Dosages may range from 15 mg to 37.5 mg per day, as prescribed by a healthcare professional. 

Common side effects of Phentermine may include:

• Increased heart rate
• Elevated blood pressure
• Insomnia
• Dry mouth
• Constipation
• Headache
• Dizziness
• Restlessness

Less common but more severe side effects may include:

• Severe chest pain
• Shortness of breath
• Fainting
• Swelling of the legs or ankles
• Difficulty exercising 

• Phentermine should only be used under the supervision of a healthcare professional and as part of a comprehensive weight loss program.
• It is not recommended for individuals with a history of heart disease, uncontrolled high blood pressure, hyperthyroidism, glaucoma, or a history of drug abuse.
• Phentermine may interact with certain medications, so it's important to inform your doctor about all prescription and over-the-counter drugs, supplements, and herbal products you are taking.
• Phentermine has the potential for abuse and dependence, so it should be used with caution and only for the prescribed duration.