D-pinitol, another chemical structure of 3-O-methyl-D-chiro-inositol, is an important insulin-sensitizer. The purpose of this review is to examine the characteristics of pinitol and other analogs as functional food biomaterials which were well known to reduce blood glucose levels. Pinitol can be converted to chiro-inositol in normal humans, while diabetic patients can not use the molecule, resulting in exhibiting low level of chiro-inositol in their urine. Recently, it is reported that pinitol can trigger phospholipase C/D, thus the rate of glucose metabolism accelerates to use as fuel for human body. To not only reduce insulin resistance of diabetic patients, but also alleviate the symptoms of diabetes, obesity, and muscle contraction, pinitol and its dietary supplementation is needed.