Phentermine functions like an amphetamine. The compound alters your central nervous system, elevating your heart rate while lowering your appetite. Phentermine is a common weight loss drug for people with diabetes and high cholesterol.
The drug convinces your brain to release more neurotransmitters. These hormones control your metabolism and appetite and “trick” you into exercising more and eating less. Side effects can include dizziness, chest pain, headaches, and trouble breathing.