Are there any side effects of phentermine?

Donna Hill Howes, RN
Family Practitioner

Side effects may include insomnia, restlessness, dizziness, headaches, mood changes, high blood pressure, a rapid, strong or irregular heartbeat, dry mouth, diarrhea, and vomiting. Rarely, heart valve problems have been reported, and there may be a risk of pulmonary hypertension. Phentermine may be habit forming, and it can make it dangerous to drive or to operate machinery. 

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.