Read the label. Different companies have different recipes. If it is Kikkoman soy sauce, it does not have MSG per say. It is made with a fermentation process to get the flavor. The online sources suggest that the fermentation process produces “processed free glutamic acid (MSG)”

Be careful, MSG can be hidden under natural flavor, hydrolized protein contains processed free glutamic acid (MSG) Here is a web page that may help: http://www.truthinlabeling.org/MSG.Aliases.Exposed.htm

I have been sensitive to MSG for a long time.