New evidence
Meta-analysis of 340 perimenopausal women finds soy isoflavones modestly reduce headache frequency and psychosocial symptoms — but had no effect on hot flushes
This is the first solid systematic review to tease apart which menopausal symptoms respond to soy isoflavones and which don't, but the headache result, while statistically significant, comes from only three small trials and the dose that worked is unclear.
A meta-analysis of 3 studies with 340 perimenopausal women found that soy isoflavones reduced headache symptoms by a moderate amount (Hedges' g = -0.38) compared to placebo. The same analysis found no significant benefit for hot flushes or insomnia, suggesting that soy's effects on menopause are symptom-specific and not universal.
Where this fits in the evidence
This is among the first studies we've indexed on Soy for Reduced Headache Symptoms — treat it as an early signal until more research accumulates.
The study
- Meta-Analysis
- n = 748
- 2025-07-23
- PeerJ
- PubMed: 40718787
- DOI: 10.7717/peerj.19715
- Full study breakdown →
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