MSG has a bad reputation, but undeservedly so. Most of the Western animus towards MSG started in the late 60s with a single person summing up a series of symptoms into what he called “Chinese restaurant syndrome” and blaming it on the MSG that was being added to the food. There was actually no basis for this claim–it was just a theory he had–and no scientific evidence to support the idea that MSG is harmful to humans. Like many other misinformation campaigns, this one took off and the public bought into the idea that MSG was the cause of a host of mysterious ailments.
MSG is a naturally occurring compound that is found in a wide variety of foods you already eat, such as tomatoes and cheese, and is part of a collection of compounds called glutamates, which are found in all kinds of food. Like salt, it enhances the natural flavor of umami-rich food, making food taste richer, deeper and more fulfilling. You can buy MSG from most any grocery store, with the salt and spices, under the label “Accent”. You can also find it in Asian markets under many different brands and packaging options.
If you want to get that flavor enhancement, but you’re reluctant to use straight-up MSG, there are some alternatives. Two I would recommend are dried mushroom powder and nutritional yeast (Bragg’s is the most common brand).