Vitamin C is good for colds, flu, fatigue, increased energy requirements, etc. In addition, vitamin C is a free radical scavenger and antioxidant protection and enhances the immune system, especially when combined with zinc or glutathione. It is gratifying that a high dose preparation with delayed release (time released) is the active substance ascorbic acid available. By combining with citrus bioflavonoids availability of vitamin C is increased in the body.
Conclusion: A very good product at a relatively high price. A similar product is also available at Amazon from another seller about half price.
PS from 10/13/2013: In the meantime, the price was significantly lowered