E621

MSG (Monosodium Glutamate)

Controversial Flavour Enhancer & Umami Taste

What is E621 (MSG)?

E621 is Monosodium Glutamate (MSG), the sodium salt of glutamic acid – an amino acid naturally found in many foods.

How it works:

• Enhances "umami" flavour – the savoury, meaty taste
• Activates glutamate receptors on the tongue
• Makes food taste richer and more satisfying

Why it's used:

• Intensifies savoury flavours in processed foods
• Reduces need for salt (30-40% less sodium possible)
• Cheap and effective flavour enhancer
• Masks off-flavours in low-quality ingredients

Where is MSG Found?

Processed Foods (Very Common):

• Crisps and flavoured snacks
• Instant noodles and ramen
• Stock cubes and gravy granules
• Packet soups and sauces
• Ready meals
• Processed meats (sausages, ham)

Restaurant Food:

• Chinese, Japanese, Korean cuisine (not always – depends on restaurant)
• Fast food (burgers, fried chicken)
• Pizza

Natural Sources (Glutamate):

Glutamate occurs naturally in many foods:

• Tomatoes (especially concentrated tomato paste)
• Parmesan cheese (very high glutamate)
• Soy sauce
• Mushrooms
• Seaweed (kombu – used to make MSG originally)
• Aged cheeses
• Cured meats

Is MSG Safe? What Does Science Say?

✅ Major Scientific Reviews:

• FDA (US): "Generally Recognized As Safe" (GRAS)
• EFSA (EU): Approved with ADI of 30mg per kg body weight
• WHO/FAO: No ADI needed – safe at normal levels
• Multiple large studies: Found no serious health risks at typical consumption

The "Chinese Restaurant Syndrome" Debunked:

In 1968, a doctor wrote a letter (not a peer-reviewed study) to the New England Journal of Medicine claiming symptoms after eating Chinese food. This sparked decades of MSG fear.

What science found:

• Double-blind studies: When people don't know they're eating MSG, symptoms disappear
• Placebo effect: People who think they're sensitive get symptoms from placebo MSG
• No consistent evidence: Symptoms don't reliably occur with MSG consumption
• Racist origins: The term unfairly stigmatized Chinese cuisine

Verdict: "Chinese Restaurant Syndrome" is not a real medical condition. Symptoms after Chinese food more likely due to large portions, high fat, alcohol, or other ingredients.

Real (But Rare) MSG Sensitivity:

A small percentage of people may genuinely experience mild symptoms from large doses of MSG on an empty stomach:

• Headache
• Facial flushing
• Sweating
• Chest tightness (rare)

Important: These symptoms are temporary and not dangerous. They typically occur only with very high doses (3+ grams on empty stomach).

Health Concerns (What to Actually Worry About)

1. Appetite Stimulation & Weight Gain

MSG may affect appetite regulation:

• Makes food taste better – you may eat more
• Some studies link high MSG intake to increased obesity risk
• May interfere with leptin signaling (fullness hormone)

Concern: Not toxic, but may contribute to overeating and weight gain.

2. Excitotoxicity (Overblown Concern)

Some claim MSG causes "excitotoxicity" – overstimulation of brain neurons:

• Theory: Excess glutamate damages brain cells
• Reality: Your brain has a blood-brain barrier that blocks dietary glutamate from entering the brain
• Verdict: No evidence MSG from food harms the brain in humans

3. Sodium Content

MSG contains sodium (about 12% by weight):

• Less than table salt (39% sodium)
• Can reduce overall sodium if used to replace salt
• Still adds sodium – consider if on low-sodium diet

Regulatory Status

UK/EU: Approved with ADI of 30mg per kg body weight

US: FDA "Generally Recognized As Safe" (GRAS)

Australia/New Zealand: Approved (Code 621)

Label requirement: Must be listed as "monosodium glutamate" or "E621" – can't be hidden

Who Should Limit MSG?

⚠️ Consider Limiting:

• People who report sensitivity – trust your body (even if it's placebo, avoid if it bothers you)
• Those watching weight – may increase appetite and food intake
• People on low-sodium diets – MSG adds sodium

✅ No Need to Avoid:

• Most people can consume MSG without issues
• Natural glutamate in tomatoes, cheese, etc. is chemically identical

MSG vs Natural Glutamate

Key fact: MSG is chemically identical to the glutamate naturally found in tomatoes, cheese, and mushrooms.

• Your body can't tell the difference between synthetic MSG and natural glutamate
• Both are metabolized the same way
• If MSG were truly harmful, so would Parmesan cheese and tomatoes

The Bottom Line

• ✅ Generally safe – approved by all major food safety agencies
• ✅ "Chinese Restaurant Syndrome" is a myth – debunked by science
• ⚠️ Small percentage report sensitivity – mild, temporary symptoms
• ⚠️ May increase appetite – concern for weight management
• ✅ Chemically identical to natural glutamate in cheese, tomatoes
• ✅ Can reduce sodium intake when used to replace salt
• ⚠️ Used to mask poor ingredients in ultra-processed foods

Our recommendation: MSG is safe for most people. The bigger concern is the ultra-processed foods that contain it. Focus on whole foods, and don't worry about the occasional packet of crisps with MSG. If you notice symptoms, limit intake – but know the science suggests it's likely other factors.

Last updated: February 2026