GNC B-Complex + Energy is a dietary supplement that combines 8 key B-vitamins with 100 mg of caffeine to support metabolism and energy production. The B-vitamins help convert food to fuel and support metabolic processes in the body. The added caffeine enhances mental alertness and performance. This product is designed to deliver nutrients at ideal times to facilitate absorption and features 100 mcg of vitamin B-12 for energy production and red blood cells. It is a sustained release energy-boosting formula that supports focus and mental alertness.