Natural energy. Boosts metabolism & supports fat loss (In combination with calorie-reduced diet designed for weight lo and an active lifestyle C4 Smart Energy supports fat loss by increasing caloric expenditure). Natural Energy: Caffeine derived from green coffee beans. Boosts Metabolism & Supports Fat Loss: Accelerates calorie burning. Sharpens Mental Focus: Clinically studied to elevate alertness. Promotes Well-Being: Designed to help your best. Zero artificial colors.