Objectives: To evaluate the labeling accuracy of four myo-inositol products, designed for polycystic ovary syndrome (PCOS) treatment, available on the italian market and to perform a cost comparison based on myo-inositol content in milligrams for products analyzed.
Materials and methods: Four (4) myo-inositol products (3 sachet and 1 tablet formulations) were dissolved using water, and each sample was analyzed for myo-inositol content using a high-performance liquid chromatography (HPLC) method with index refraction detector. The amount of myo-inositol per purchased product was then divided into its purchase price in order to make cost comparisons between the products based on a 2 and 4 g/day dose.
Results: A significant difference in the myo-inositol content, compared with the labeling was found for the products. Only 1 product contained more than 95% of the myo-inositol content claimed on the label, and there was a product with less than 75% of the labeling amount. Based on a 2-g myo-inositol per day dose, the cost of a 30-day supply ranged from Euro 20,77 and Euro 71,86, after correction by actual amount of myo-inositol.
Conclusion: There is a lack of conformity between declared and actual amount of myo-inositol among the products tested and the majority of the products contained less than 95% of labeled amounts. There should be a better control in the manufacturing process in order to ensure more quality and accuracy. Nowadays consumers cannot trust myo-inositol product labels to represent the product's content accurately or that product pricing is a reflection of myo-inositol content.