Whey protein is derived from milk and is one of the richest sources of branched-chain amino acids. Whey protein is rapidly digested and assimilated. You'd have to look at the label to see if the casein has been removed.

One of the primary advantages of casein (produced from skim milk), is that it contains all of the essential amino acids and more glutamine and tyrosine than any other protein. Glutamine is a precursor to glutamic acid, which serves as fuel for the brain, while tyrosine is a precursor to thyroid hormones and the neurotransmitter, dopamine.

For vegetarians, I believe Spirulina is one of the richest sources of vegetable protein, providing 65-71% protein in the form of all 8 essential amino acids in their proper ratio. In fact, much of the protein in Spirulina is called biliprotein, which means the protein has already been predigested by the algae, making it easier to break down than meat or soy protein. Here's more info: Spirulina and here's where you can get a good quality brand that has been tested for heavy metal contaminants: Spirulina capsules

Chlorophyll is usually the form "sodium copper chlorophyllin" so my understanding is that the copper may be troublesome for some mercury toxic people. I don't know this for certain, so if anyone has more information, please let us know.