Chlorella has very hard outer shell, making it almost completely indigestible to humans, so supplemental forms undergo a special process that cracks this outer shell for enhanced digestibility. It is one of the most-used supplements in Japan. One chlorella cell is only 5 microns (.000195 inches) in diameter, but is a well-defined plant with a nucleus and a full complement of nutritious and health-building substances. Chlorella is so small that it cannot be seen without microscope. Plus
