Monosodium glutamate

Studies in people

• Concern

  Headaches after eating³

  In some studies, monosodium glutamate caused headaches in people who took it without food, but other studies found no clear link.

• Open question

  Headaches and migraines⁵

  Scientists do not yet know whether monosodium glutamate triggers headaches, as studies give conflicting results.

• No harm found

  Allergy and asthma symptoms⁶

  Decades of research have not shown a clear link between eating monosodium glutamate and asthma, hives, or a runny nose.

• Concern

  Symptoms after eating⁸

  Some people get headaches, sweating, stomach pain or rashes after eating monosodium glutamate in Chinese food.

• No harm found

  Headaches and asthma¹⁰

  Despite its reputation, studies have not shown that monosodium glutamate reliably causes headaches, asthma attacks, or other symptoms.

• Benefit

  Blood sugar after meals¹¹

  In people, monosodium glutamate added to a liquid meal lowered blood sugar early on, possibly by boosting a gut hormone.

• No harm found

  Asthma attacks¹²

  In people with asthma, eating monosodium glutamate did not bring on asthma attacks or breathing problems.

• Open question

  Hives from food additives¹³

  In people with long-lasting hives, monosodium glutamate rarely set off a reaction in this study.

• Benefit

  Blood sugar levels¹⁵

  In Chinese adults, eating more monosodium glutamate was linked to a lower risk of high blood sugar.

• Concern

  Sleep and breathing at night¹⁷

  In Chinese adults of normal weight, eating more monosodium glutamate was linked to more snoring and a higher chance of sleep-disordered breathing.

• Open question

  Food choices at meals¹⁹

  In diabetic patients, monosodium glutamate in vegetables and starch made them eat more starch but not more total food.

• No harm found

  Asthma risk²⁰

  In Chinese adults, monosodium glutamate intake was not significantly linked to asthma, though a traditional food pattern was.

• No harm found

  Stomach acid after eating²¹

  Adding monosodium glutamate to soup did not change how much acid or gastrin people's stomachs released.

Animal and lab studies only

• Concern

  Brain and liver effects²⁹

  In animal studies, eating monosodium glutamate was linked to brain and liver problems, but the authors say more research is needed.

• No harm found

  Brain development in young rats³⁰

  In animal studies, young rats fed monosodium glutamate showed no clear signs of harm to brain development.

• Concern

  Baby development in pregnancy³¹

  In animal studies, monosodium glutamate eaten during pregnancy and nursing changed baby rats' brains, hearts and kidneys.

• Concern

  Weight gain and obesity³²

  In animal studies, monosodium glutamate caused weight gain and obesity, but scientists still disagree about what it does in people.

• Concern

  Colon lining in rats³³

  In animal studies, monosodium glutamate changed the colon lining of rats, but soy milk added to their diet restored it.

• Concern

  Lung and airway changes³⁴

  In animal studies, rats given monosodium glutamate alongside radiation showed lasting changes to their airways and lungs.

• Concern

  Mood and depression³⁵

  In animal studies, rats that drank monosodium glutamate for 30 days showed more signs of depression-like behavior.

• Concern

  Newborn liver development³⁶

  In animal studies, monosodium glutamate eaten during pregnancy and nursing changed liver cell parts in rat pups.

• Concern

  Baby brain and heart development³⁷

  In animal studies, monosodium glutamate given to pregnant and nursing rats changed their pups' brains, hearts and livers.

Study type not stated

• Concern

  Food additive health risks²³

  MSG is a common food additive that studies link to high blood pressure, obesity and gut trouble.

• Open question

  Organs and body systems²⁴

  Scientists reviewed studies on monosodium glutamate and say more research is needed on how it affects the body.

• Concern

  Sensitivity to food additives²⁵

  Some people may be sensitive to monosodium glutamate, though studies have not confirmed this.

• No harm found

  Brain function concerns²⁶

  Eating monosodium glutamate in food does not raise brain glutamate levels or disrupt brain function.

• No harm found

  Weight gain concerns²⁷

  Eating monosodium glutamate is unlikely to affect your weight, fat metabolism or how much you eat.

Allergies and intolerances

These are about people with an allergy, an intolerance or coeliac disease. The signal is about the ingredient itself, and these are about the person eating it, so the signal does not count them.

• Food allergy claims⁹

  Studies show monosodium glutamate rarely causes real allergic reactions, though some people may feel briefly unwell.

Single cases of misuse or overdose

One person or one incident, such as an accidental overdose or a mistake in a kitchen or factory. They are real, but a single case does not show what happens at normal amounts, so the signal does not count them.

• Asthma and hives after eating²²

  In one person, monosodium glutamate brought on asthma and hives, but allergy tests were negative.

How it’s made and used

• How body processes it⁴

  Your body handles glutamate from monosodium glutamate the same way it handles glutamate from ordinary protein foods.

• Everyday food consumption levels⁷

  Scientists worked out how much monosodium glutamate people in China eat each day from everyday foods.

• Flavor liking and appetite¹⁴

  In people, eating soup with monosodium glutamate made them like that soup more and eat more of it later, even without MSG.

• Taste preference and protein¹⁶

  Men who usually eat lots of protein liked strong monosodium glutamate taste more after a low-protein breakfast.

• Salty taste enhancement¹⁸

  Monosodium glutamate made salty taste stronger in taste tests, especially when only a little salt was cut.

• How much is in stock cubes²⁸

  Monosodium glutamate levels differed between stock cube brands, and chicken cubes had less than beef ones.

The signal at the top counts the findings in people and in animal and lab studies. A concern in studies of people outranks animal and lab studies, and “No concerns” needs at least one finding in people. When most findings in people point one way, the page leans that way (“Mostly”), and every finding is still shown. Findings whose study type is not stated are shown but not counted. This page is a reference, not medical advice. It describes what regulators and published research say. Talk to a doctor or dietitian about your own diet.

Expert panels that weigh all the research. Shown for context: the signal at the top does not count them.

• UN and WHO food additive experts (JECFA), 1987

  No daily limit needed (“ADI not specified”, JECFA’s term for very low toxicity).