I have taken supplements for many years. Most are trials and errors based on the recommendations from books, website review or popularity. I also read extensive on nutrition and health websites about latest studies on the supplements. I tried to write a neutral review that shows both sides of the product. Most often the bad points are only discovered after using and some research. Many of the health products are amazing. However, I give many of the supplements 4 stars only though they are very good too. I only give 5 stars to the best of them. The reason that they only have 4 stars can be that it contains flow agents (eg magnesium stearate), overpriced, uses of fillers (eg flour, calcium etc), binders, poor container for storing, misleading information etc.