Inositol is the most well-research and evidenced backed supplements for PCOS. In this article, I want to investigate exactly why it is so beneficial for PCOS and, what exactly it is that it does.What Is Inositol? Inositol, sometimes referred to as vitamin B8, is actually not a vitamin, it’s a form of sugar with several important functions, such as being a major component of cell membranes - this is important to note when understanding how it helps insulin sensitivity. There are nine forms, or stereoisomers of inositol. With myo-inositol being the most well known and researched. Inositol naturally occurs in foods such as fruits, beans, grains and nuts. Your body can also naturally produce inositol from the carbohydrates you eat, although, research suggests that additional inositol in the form of supplements may have numerous health benefits.