Monosodium Glutamate (MSG): An Excitatory Neurotoxin That is in Everything!

Monosodium Glutamate, or MSG for short, is one of those food additives that appears to be very safe when in fact it’s quite dangerous. There is a great deal of confusion about MSG. Because it is not regulated, and because it can be found in many forms and called so many different names, many of which sound very healthy, it is difficult for those in the know, and impossible for the uninformed, to avoid it. Adding to the confusion, is the fact that it can be harmless in some forms, while being extremely harmful in other forms.

In this article we will provide a comprehensive list of the names used, definitions that clarify which forms are dangerous and which are not and tips on how to avoid MSG.

Safe Forms of MSG:

  • Unprocessed and Unbound Glutamic Acid. Monosodium Glutamate, which is unbound, or free, can be found naturally in very small amounts in foods such as cheese, ripe tomatoes, fermented soy products, and yeast extracts.  For those who are allergic to MSG in it’s natural form, they must avoid these foods. For everyone else, naturally occurring MSG is not a problem. 
  • Bound and Unprocessed Glutamic Acid. In addition to the small amounts of unprocessed free glutamic acid, we also have bound glutamic acid, which is not only harmless, but like most of the amino acids, a building block for muscle and many other important functions. Bound (unprocessed) glutamic acid is found in proteins in much higher concentrations than the unbound naturally occurring MSG. The bottom line is that neither the unprocessed unbound or the unprocessed bound glutamate cause adverse reactions in the vast majority of people and one is a building block for muscle.

Unsafe L-Glutamate

  • Processed Unbound (free) Glutamic Acid aka MSG. Monosodium Glutamate becomes an excitotoxin when it is processed by converting bound glutamic acid into free glutamic acid, which is then manufactured as a food additive. In this state, it is a neurotoxin and a stimulant that is toxic and highly addictive. That is a double whammy. Now instead of a little jolt of excitement, we get a relentless firing of neurons that cause cravings, food addictions, obesity and it’s complications, inflammation, autoimmune disorders and various cancers.  In this state it is referred to as L-Glutamine.

The Dangers of Ingesting MSG

Excitotoxins are not only dangerous, they are also difficult to detect until they have done considerable damage.  Retired neurosurgeon Russell Blaylock, MD (author of Excitotoxins: The Taste That Kills) claims there is growing evidence that excitotoxins are a major cause of degenerative brain diseases in adults including Alzheimer’s, Parkinson’s, Huntington’s, ALS and MS diseases. He has also stated that once ingested (or injected) excitotoxins interact with one another and increase the toxicity of each chemical a hundred-fold. He points out that one of the most pervasive and destructive excitotoxins is Monosodium Glutamate or processed free MSG.

The following is a simplification of how L-Glutamine causes disease:

1. Foods containing L-Glutamine, aka MSG, are eaten and attack the body. The cells in the hypothalamus that regulate appetite are a target and are destroyed over time. They are literally stimulated to death by L-Glutamine, which is why it is referred to as an excitatory neurotoxin. It is a mechanism similar to that which takes place when we get high from any drug. The brain can be “fried” by one bad LSD trip or more slowly from repeated use of cocaine.  Processed L-Glutamine, or MSG, behaves in the same way. The difference is we know when we are abusing drugs, we do not know that we are being poisoned by foods that we eat every day.

One of the mechanisms making this possible is that L-Glutamine damages Leptin receptors.  Leptin is the hormone that regulates appetite and fat storage.   It is found in fat tissue.  It turns out that fat is an organ, or at least it behaves like other organs, in as much as it has it’s own hormone. 

Leptin’s job is to send a message to the Hypothalamus to stop eating and stop storing fat when the body has enough fat stored. Unfortunately, L-Glutamine excites Leptin receptors to death so that the hypothalamus no longer receives these messages. This is called leptin-resistance.

2. In the obese individual, Leptin is high, due to excess body fat, but it may not be functional because of damage from MSG.  In other words, if the individual is eating foods containing L-Glutamine, (and highly palatable foods are loaded with MSG) the Leptin receptors become too damaged over time to receive the message that there is enough fat on board. When this happens, it does not send the do not eat, do not store fat message.  Thus the individual feels hungry despite having eaten, and stores fat despite having an abundance of fat already on board.  That’s not good, right?

But It Gets Worse!

3. Glutamate also activates AMPK, which is an enzyme responsible for conserving energy.  AMPK slows metabolism and reduces our need for physical activity.  In the lab, it creates “lazy mice” that are fat and tend to sleep a lot. Under normal circumstances when Leptin levels rise, due to higher levels of fat storage, the production of AMPK stops, allowing us to resume burning calories and feeling energetic. 

The exception is when a food contains L-Glutamine. (Have I mentioned that almost all processed foods, even many of the organic ones, contain MSG?) The reason for this is that glutamate, which is needed for learning and the formation of short-term memories, must have access to the hypothalamus. Since the brain doesn’t differentiate between natural glutamate and L-Glutamine, it allows both to pass through the blood-brain barrier. 

That bears repeating: The hypothalamus cannot tell the difference between Glutamate, which is an amino acid, and L-Glutamine, which is a neurotoxic denatured protein in the form of MSG. Under normal circumstances, Glutamate overrides Leptin, which is what it is supposed to do.  Unfortunately, so does L-Glutamine. So the brain ignores signals from Leptin to stop conserving energy by slowing our metabolism and stop storing fat.  In other words, the Leptin levels are not registering, so there is nothing to stop the production of AMPK, which causes more fat storage.

What ends up happening is: 

  • Appetite stays high – so calorie intake goes up
  • Activity is depressed – so calories burned go down
  • Metabolism slows down
  • Weight goes up

A plethora of disorders result from L-Glutamate. This is because L-Glutamine enters the bloodstream up to 10 times faster than bound glutamates. Because there are glutamate receptors in many parts of the body, including the brain, heart, lungs and pancreas, consuming large amounts of it “overwhelms” many of the body’s systems by over-stimulating receptor neurons. However, until very recently, the medical establishment seems to have missed this epidemic.  

This is likely because so many of the body’s systems are involved with conditions driven by MSG.  The most common ones today are autoimmune disorders, which, when combined, are currently the third cause of death in the US, surpassing cancer and heart disease.  The result is that the patient presents with a variety of symptoms, each of which is treated by a different specialist.  When specialists get involved, treatment focuses upon their area of specialty, i.e. patients suffering from joint problems, like rheumatoid arthritis and lupus, see a rheumatologist and are treated with medications that focus on those symptoms, whereas those with skin issues, like psoriasis, are treated by dermatologists and usually with something topical or with a steroid, and so on.  No one is tasked with looking at the cause or source of the problem, because the treatment is symptom focused, so the problem just keeps getting worse. In many cases, the treatment becomes part of the problem.

Damaged Proteins 

In general,  separating a protein or freeing it, which occurs when we heat it, results in L-Glutamine. The best, and most common example, is pasteurizing milk.  Even if the cows are grass-fed, pasteurization denatures the otherwise perfect proteins, causing them to behave like L-Glutamine.  This is why the raw milk movement is so popular.  In Ohio, where I reside, one must buy into a herd share to obtain raw milk and dairy, but it is worth it. This is not to say that pasteurized milk is not beneficial.  If you buy milk, go for the lightly pasteurized, not ultra pasteurized milk, if you cannot find or afford raw milk.

According to the Truth in Labeling Organization When It Comes to Protein that Contain MSG:[1]

  1. Low fat and no fat milk products often contain milk solids that contain MSG and many dairy products contain carrageenan, guar gum, and/or locust bean gum, all of which are forms of MSG.  
  2. Protein powders contain glutamic acid, which, invariably, will be processed free glutamic acid (MSG).  Individual amino acids are not always listed on labels of protein powders.  
  3. Hydrolyzed protein is the main problem.  At present there is an FDA requirement to include the protein source when listing hydrolyzed protein products on labels of processed foods.  Examples are hydrolyzed soy protein, hydrolyzed wheat protein, hydrolyzed pea protein, hydrolyzed whey protein, hydrolyzed corn protein. If a tomato, for example, were whole, it would be identified as a tomato. Calling an ingredient tomato protein indicates that the tomato has been hydrolyzed, at least in part, and that processed free glutamic acid (MSG) is then present.
  4. Disodium guanylate and disodium inosinate are relatively expensive food additives that work synergistically with inexpensive MSG. When you see either of them, it suggests that the product has MSG in it.  They would probably not be used as food additives if there were no MSG present.
  5. MSG reactions have been reported from soaps, shampoos, hair conditioners, and cosmetics, where MSG is hidden in ingredients with names that include the words “hydrolyzed,” “amino acids,” and/or “protein.”  Most sun block creams and insect repellents also contain MSG.
  6. Drinks, candy, and chewing gum are potential sources of hidden MSG.
  7. Binders and fillers for medications, nutrients, and supplements, both prescription and non-prescription, enteral feeding materials, and some fluids administered intravenously in hospitals, may contain MSG.
  8. According to the manufacturer, 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.  It would appear that most, if not all, live virus vaccines contain some ingredient(s) that contains MSG.
  9. 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.  The time lapse between ingestion and reaction is typically the same each time for a particular individual who ingests an amount of MSG that exceeds his or her individual tolerance level.
  10. Remember: By food industry definition, all MSG is “naturally occurring.” “Natural” on the label doesn’t mean safe or MSG free.  “Natural” only means that the ingredient started out in nature, like arsenic and hydrochloric acid, both or which are poisonous.

Case History

My favorite story is one in which a patient came to me extremely depressed because her fiancé had dumped her when he discovered that she had Multiple Sclerosis. Her doctor told her that she would be in a wheel-chair and disabled for the rest of her life and that the MS would continue to worsen.  She was a VP at a fortune 10 company. 

During our intake it became apparent that she lived on processed foods, which are loaded with MSG, but also on artificial sweeteners that have the same impact as the MSG. Prior to working with me, this young woman rarely ate real food.  She was a road warrior and ate most of her foods in airports and hotels from a bag or a can. Really terrible diet. She kept her energy up with sugar free gums that are loaded with aspartame and other dangerous sweeteners. 

I explained that if she did not want to spend the rest of her life in a wheelchair, she would have to embrace clean eating.  She is the best example of a convert that I have ever treated.  She is the only patient I have that may eat “cleaner” than I do.  No more processed anything, everything organic, whole and no more food additives like MSG or aspartame/acesulfame.  

Within the first year, she went from the worst form of MS to the best. After 2 years, I discovered Low Dose Naltrexone and recommended that she try it and within a year of trying it, she tested negative for MS. Technically, she is not cured, but practically she is.  She and her new husband (her former internist) now reside in sunny California where she can absorb Vitamin D3 as recommended.  They have a two-year-old. 

 This is because aspartic acid (from aspartame) and glutamic acid (from MSG) can both stimulate a receptor in the brain called the NMDA receptor (n methyl d aspartate). Chronic overstimulation of the NMDA receptor over time is neurotoxic! As Dr. Russell Blaylock explains in his book, Excitotoxins: The Taste that Kills , aspartame and MSG excite brain cells to the point that they die.

Other Legal Mechanisms For Dosing Us With L-Glutamine (MSG) 

The manufacturers of L-Glutamine are relentless in finding ways of getting us to ingest MSG.Here are the most common methods:

  • As a By-Product – Though previous reports have disallowed MSG in foods for infants or those under one year of age, as we saw above, many infants and children still ingest MSG that is a by-product of the processing of protein, such as hydrolization or autolyzation, and therefore listed under another name such as brewers yeast or citric acid.  
  • As Part Of Another Ingredient – It may also be part of an ingredient such as Sucralose, aka Splenda, which is partly L-Glutamine. 
  • In Infant and Childhood Vaccinations – Many infants and children in the US also receive doses of MSG in their vaccinations, which also include MSG:
    • MMR – Measles-Mumps-Rubella
    • M-R-Vax – Measles-Rubella, Merck & Co., Inc.
    • Attenuvax – Measles, Merck & Co., Inc.
    • Biavax – Rubella, Merck & Co., Inc.
    • Prevnar Pneumococcal – 7-Valent Conjugate Vaccine, Wyeth Lederle 
    • Varivax – Chickenpox, Merck & Co., Inc.
    • YF-VAX – Yellow Fever, Aventis Pasteur USA[1]

From corn-fields to hospitals, school cafeterias, and nursing homes MSG is added to mass-produced food with no restrictions and no notice. MSG awareness activists call it nicotine for food. The problem with this analogy is that we know when we are smoking a cigarette that it contains nicotine. But how many young women today know that they are being exposed to a major toxin causing irreparable damage to their child even before they discover they are pregnant?


  1. The Slow Poisoning of Mankind. By John Erb
  2. Lifestyle Choices…Up to YOU! Biblical and Health Guidelines for More Abundant Living. By Ginger Woods O’Shea.
  3. See “MSG Is Being Sprayed On Fruits, Veggies, Nuts, Grains And Seeds As They Are Growing…Even Those Used In Baby Food. “
  4.  Prepared by the Truth in Labeling Campaign Web page:

Dr. Renae Norton specializes in the treatment of eating disorders. Located in Cincinnati, Ohio. Call 513-205-6543 to schedule an appointment or fill out our online contact form for someone to call you to discuss your concerns. Tele-therapy sessions available. Individual and family sessions also available.

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Materials contained on this site are made available solely for educational purposes and as part of an effort to raise general awareness of the psychological treatments available to individuals with health issues. These materials are not intended to be, and are not a substitute for, direct professional medical or psychological care based on your individual condition and circumstances.  Dr. J. Renae Norton does not diagnose or treat medical conditions. While this site may contain descriptions of pharmacological, psychiatric and psychological treatments, such descriptions and any related materials should not be used to diagnose or treat a mental health problem without consulting a qualified mental health care provider.  You are advised to consult your medical health provider about your personal questions or concerns.