Monosodium glutamate and headache in human studies
What it found
In studies where people took monosodium glutamate with food, headache rates were mostly the same as with a placebo.
In studies without food, results were mixed, and many were poorly blinded.
What they found
Studies in people
With food
Of six studies where monosodium glutamate was taken with food, none found a significant difference in headache rates except one group of women. That study used 3 g in 150 ml beef broth.
Without food
Of seven studies where monosodium glutamate was taken without food, four found a significant difference in headache rates. Doses in these studies ranged from 1.25 to 12 g, usually dissolved in liquid.
Taste and blinding
Many studies gave monosodium glutamate in solution at concentrations above 2 percent. The authors say people can taste the difference at these levels, so the studies may not have been properly blinded.
Self-identified sensitive people
Two studies that found a difference recruited people who believed they were sensitive to monosodium glutamate. The authors say blinding problems may have a stronger effect in these people.
Blood glutamate levels
One study found that when 100 mg/kg monosodium glutamate was added to meals, blood glutamate levels changed by about 10 percent over the day. The authors say this is within normal daily variation.
Animal and lab studies
Animal study cited
One paper cited by the headache classification was a lab study on rabbit aorta. The authors say it has little relevance because eating monosodium glutamate has little impact on blood glutamate levels.
What the authors conclude
“Because of the absence of proper blinding, and the inconsistency of the findings, we conclude that further studies are required to evaluate whether or not a causal relationship exists between MSG ingestion and headache.”
Also in their conclusions
- They conclude that a causal relationship between monosodium glutamate and headache has not been proven.
- They suggest that further studies are required to evaluate whether or not a causal relationship exists between monosodium glutamate ingestion and headache.
- They say it would seem premature to conclude that the monosodium glutamate present in food causes headache.
How it was done
Monosodium glutamate is listed as a cause of headache in the International Classification of Headache Disorders, but the authors say no one had comprehensively reviewed the human evidence for a causal link.
They searched Medline and FSTA for human studies where healthy adults took monosodium glutamate by mouth and headache was recorded. They found 10 papers: 5 with food (doses 1.5 to 3.15 g) and 5 without food (doses 1.25 to 12 g).
What it can’t tell you
- The studies used different doses, ways of giving monosodium glutamate, and types of people, so the results cannot be combined into one clear answer.
- Many studies may not have been properly blinded because people could taste the monosodium glutamate, which could affect whether they reported a headache.
- This review cannot show that monosodium glutamate causes headaches or that it does not.
Who paid
- Authors work at
- Suzuka University of Medical Science, Japan
The paper
- Title
- Does monosodium glutamate really cause headache? : a systematic review of human studies
- Type
- Systematic review
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Obayashi Y, Nagamura Y (2016). Does monosodium glutamate really cause headache? : a systematic review of human studies. The journal of headache and pain. doi:10.1186/s10194-016-0639-4Free full textPubMed 27189588DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error