This review presents some recent discoveries of ancient Chinese herbal formulas evolved through thousands of years of clinical practice. It appears that many of the ancient combination formulas have sound scientific basis through modern pharmacological evaluation. Significant chemical changes occurred during the preparation (decoction) process of a prescribed herbal formula. For example, some toxic ingredients were significantly reduced and new active compounds generated due to the chemical interactions among the ingredients. Many combination formulas showed significantly better pharmacological results than individual herbal medicines participated in the formula. These findings suggest that the current drug screening and regulatory methodology will not be appropriate for the development of a botanical drug containing a group of phytochemicals, in which a synergistic interaction from chemical ingredients plays a fundamental role in the treatment of disease. If we view a diseased state in a holistic and dynamic way, i.e. it involves interactions among many biological systems in human body and these interactions change as the disease improves or worsens, the treatment of such disease with a single chemical entity may not be logical or technically feasible. Combination formulas may hold the potential to become the therapeutics of choice in the future due to the synergistic effect and dynamic adjustment achieved by the multiple ingredients that will restore the balance of an imbalanced or diseased human body.