Is MSG safe during pregnancy?

What does the evidence say about MSG during pregnancy?

1. The FDA considers the addition of MSG to foods generally recognized as safe, and in controlled studies of people who identify as MSG-sensitive, researchers have not been able to consistently reproduce reactions when MSG and placebo were compared. 1
2. An average adult takes in roughly 13 grams of glutamate a day from the protein in ordinary food, compared with about 0.55 grams a day of added MSG, and the free glutamate released when protein is digested is chemically the same molecule as the glutamate in MSG. 1
3. A Federation of American Societies for Experimental Biology review concluded MSG is safe while identifying short-term, transient, generally mild symptoms such as headache, numbness, flushing, tingling, palpitations, and drowsiness in some sensitive people who consume 3 grams or more of MSG without food, an amount well above the under 0.5 grams in a typical serving. 1
4. Added MSG must be declared on the ingredient panel by name, and products containing naturally glutamate-rich ingredients such as hydrolyzed vegetable protein, autolyzed yeast, or yeast extract are not allowed to claim no MSG or no added MSG. 1
5. Human pregnancy studies on added MSG are missing rather than reassuring: one 2022 review noted that the effects of food-added MSG on human brain function do not appear to have been studied, and animal work leaves open whether any observed changes act on the mother or on the fetus. 2

Is MSG safe in each trimester?

• First trimester. There is no first-trimester restriction on MSG. Worth knowing: tomatoes, aged cheeses, mushrooms, and soy sauce are naturally loaded with free glutamate, so a diet with zero glutamate is not a real option. If early food aversions are steering you toward savoury foods, that is fine.
• Second trimester. The one reproducible effect in the research is short-lived and dose-related. Some sensitive people report headache, flushing, tingling, or drowsiness after 3 grams or more of MSG taken without food, but a typical serving of an MSG-containing food has under half a gram.
• Third trimester. MSG is a sodium salt, so if your clinician has asked you to watch sodium for blood pressure or swelling, count MSG alongside table salt rather than as a separate line item. Gram for gram it carries less sodium than salt, but it still counts.