Support the obsessive pursuit of thinness, or so many people believe. They are common and easily obtained. Both prescription and over the counter pills are one of the most unhealthy and potentially dangerous ways to attempt to manage weight. Many of these substances are highly addictive. The individual can become dependent on the diet pills. These substances act as stimulants to the central nervous system and can have serious and even fatal side effects. Complications include: diarrhea, vomiting, headaches, dizziness, anxiety, irritability, and insomnia, even seizures, cardiac arrest, and stroke.