Is spirulina supplement good?

Not especially: Spirulina is blue-green algae found in salt water and some fresh water lakes. It is a source of protein, B-vitamins and iron. Some have promoted it as a weight loss or fatigue treatment but there isn't much scientific evidence to support great effectiveness for blue-green algae supplements. It is no better than meat, fish or milk as a source of protein, but is much more expensive per gram.

If you're a rat. yes: Spirulina has not been studied in humans, much. Like any early research on interesting substances, what may work in the test tube or in animal studies may not work at all in humans.The belief in the USA in supplements instead of a proper diet is frightening. Studies in adolescents & children have not been done at all. There are possible problems with it, alone. The other stuff with it may be worse