Maximum Daily Dose of MSG for Supplement Use
I cannot recommend MSG (monosodium glutamate) as a dietary supplement based on the available evidence showing significant metabolic and organ toxicity even at commonly consumed doses.
Evidence Against MSG Supplementation
The current scientific literature demonstrates harmful effects at doses far below what would be considered "supplemental" use, making any recommendation for supplementation inappropriate.
Documented Toxic Effects
MSG causes dose-dependent hepato-cardiac toxicity in animal studies at doses of 200-600 mg/kg body weight over 28 days, with all tested doses producing dyslipidemia, inflammation, oxidative stress, and tissue damage 1
Gastric damage occurs with chronic use at doses equivalent to 1-2 grams per person (15-30 mg/kg in rats) over 10-30 days, causing erosive and ulcerative lesions, increased gastric acid secretion, and obesity 2
Metabolic disorders are linked to MSG consumption, including obesity (through hypothalamic lesions, leptin resistance, and altered PPAR expression), diabetes mellitus (via decreased pancreatic beta cell mass and insulin resistance), and hypertension 3
Regulatory Context
The European Food Safety Authority (EFSA) established an acceptable daily intake of 30 mg/kg body weight per day, though this level "is not attainable when MSG is consumed at normal dietary level" 4
For a 70 kg adult, this translates to approximately 2.1 grams per day maximum from all dietary sources combined 4
MSG is classified as Generally Recognized As Safe (GRAS) for food flavoring purposes, but this designation applies to typical culinary use, not supplementation 4
Critical Distinction: MSM vs MSG
Important caveat: If you intended to ask about MSM (methylsulfonylmethane) rather than MSG, the answer is entirely different:
- MSM is a legitimate dietary supplement with GRAS approval for supplementation 5
- MSM is well-tolerated at doses up to 4 grams daily with few known side effects 5
- MSM has anti-inflammatory and antioxidant properties, unlike MSG 5
Clinical Recommendation
Do not use MSG as a dietary supplement. The evidence shows harm at doses that would be considered supplemental, and there is no established therapeutic benefit to justify supplementation. Any MSG intake should be limited to incidental exposure from normal food consumption, staying well below the EFSA limit of 30 mg/kg/day 3, 4, 2, 1.