Reactions to MSG are dose related, i.e., some people react to even very small amounts. MSG-induced reactions may occur immediately after ingestion or after as much as 48 hours.

MSG-containing ingredients can cause adverse reactions no matter what their use -- be they in food, in things classified as drugs, in things called dietary supplements, or in things thought of as cosmetics. And some of these MSG-containing ingredients are not ingredients commonly found in food.

The amounts of MSG commonly used in pharmaceuticals and medical-related procedures are often less than amounts of MSG commonly found in food.  For that reason, consumers who react to MSG in food may not react to MSG in nonfood items. Be that as it may, people who are acutely sensitive to MSG have reported reacting to such products  And people with greater tolerance than the acutely sensitive have reported reacting after repeated exposure to such things as pharmaceuticals and supplements, i.e., after using an MSG-containing products for an extended period of time.

There are places (such as "inert ingredients" and "other ingredients") where a consumer might not think to look for hidden sources of MSG in drugs and/or supplements:

Binders, fillers, and flowing agents used in medications, nutrients, and supplements -- both prescription and non-prescription

Binders, fillers, and/or carriers (used in "enriched" products, for example), and flowing agents, may contain MSG, but are not always mentioned on labels. In pharmaceuticals, these ingredients are usually listed in product inserts under "inert ingredients" or "other ingredients."

Multi-vitamins usually include minerals that are chelated with an amino acid.  This is also true of individual minerals.  Avoid minerals with names that include the words “glutamate,” “aspartate,” or “citrate.”  Also avoid minerals with names that include a parenthesis or footnote which state “an amino acid chelate,” “an aminoate complex,” “chelated with a protein,” or “chelated with a hydrolyzed protein.”

Enteral feeding materials

Protein drinks (Boost and Ensure are examples)

Protein powders

Some fluids administered intravenously in hospitals (Dextrose in water is an example.  Saline solution might or might not contain MSG.)

Vaccines

It would appear that most, if not all, live virus vaccines contain MSG.  According to the manufacturer, the Varivax–Merck chicken pox vaccine (Varicella Virus Live), contains L-monosodium glutamate and hydrolyzed gelatin, both of which contain processed free glutamic acid (MSG) which causes brain lesions in young laboratory animals, and causes endocrine disturbances like obesity and reproductive disorders later in life.

Some pediatric drugs

Aspartame in pediatric aspirin

Gelatin

Gelatin capsules

Maltodextrin in binders and fillers

Citric acid (citrate)

Starch and corn starch

Modified food starch

Maltodextrin

Dextrose

Dextrin

Glutamate

Aspartate

Amino acids(s)

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