It is similar to the cheaper soy sauces - it consists mainly of Hydrolyzed Soy Protein, which is a way of saying you naturally created MSG - but at a lower level than the chemically created isolate substance. Is it safe this way, that is a good question...

It also has a lot of salt, like a regular soy sauce. I suppose you could substitute a naturally fermented or naturally brewed soy sauce with similar effect. These use the whole soybean instead of just the protein.