What are the side effects of taking phentermine?

Possible SE's. Potential side effects include: palpitations, rapid heart rate, ^ blood pressure, ischemic event, anxiety, insomnia, headache, tremor,dizziness, dry mouth, diarrhea or constipation & sexual dysfunction. When a medication containing phentermine in combination with fenfluramine/ dexenfluramine was on the market – pulmonary hypertension & heart valve damage occurred. .