Effects of soy isoflavones on menopausal symptoms in perimenopausal women: a systematic review and meta-analysis.

2025-07-23
PeerJ 13
- Haodi Luan
- Qianqian Liu
- Yahui Guo
- Hua Fan
- Sileng A
- Jing Lin

PubMed: 40718787
DOI: 10.7717/peerj.19715

Study Design

Type: Meta-Analysis
Sample size: n = 748
Methods: Systematic review and meta-analysis following PRISMA guidelines; screened 2,099 articles, 12 eligible for meta-analysis

Rigorous Journal

Soy isoflavones are phytoestrogens found mainly in soy and its derivatives. Given their estrogen-like and antioxidant-inhibiting inflammatory effects, they have been hypothesized to be effective in treating menopausal symptoms. We conducted a systematic review in accordance with the PRISMA guidelines. In October 2024, we screened 2,099 articles, of which 12 were eligible for meta-analysis, and found that soy isoflavones were effective for treating menopausal symptoms (seven studies, 533 participants, Hedges' g = -0.25, 95% CI [-0.42 to -0.08], p = 0.00). Soy isoflavones showed significant effects on headache (three studies, 340 participants, Hedges' g = -0.38, 95% CI [-0.60 to -0.17], p = 0.00), psychosocial symptoms (five studies, 416 participants, Hedges' g = -0.29, 95% CI [-0.48 to -0.10], p = 0.00), palpitation (three studies, 356 participants, Hedges' g = -0.42, 95% CI [-0.63 to -0.22], p = 0.00), and depression (four studies, 748 participants, Hedges' g = -0.72, 95% CI [-1.17 to -0.28], p = 0.00), but no significant treatment effect on paresthesia symptoms, fatigue symptoms, physical symptoms, hot flushes, excessive sweating, insomnia, and vasomotor symptoms was observed. However, our results should be interpreted with caution owing to the small sample size. More trials should be conducted in the future to validate our findings.

Research Insights

Soy→Reduced Depression
depression (four studies, 748 participants, Hedges' g = -0.72, 95% CI [-1.17 to -0.28], p = 0.00)
Effect
Beneficial
Effect size
Moderate
Soy→Reduced Depression Symptoms
depression (four studies, 748 participants, Hedges' g = -0.72, 95% CI [-1.17 to -0.28], p = 0.00)
Effect
Beneficial
Effect size
Moderate
Soy→Reduced Excessive Sweating
no significant treatment effect on ... excessive sweating
Effect
Neutral
Effect size
Small
Soy→Reduced Fatigue
no significant treatment effect on ... fatigue symptoms
Effect
Neutral
Effect size
Small
Soy→Reduced Headache
Soy isoflavones showed significant effects on headache (three studies, 340 participants, Hedges' g = -0.38, 95% CI [-0.60 to -0.17], p = 0.00)
Effect
Beneficial
Effect size
Moderate
Soy→Reduced Headache Symptoms
Soy isoflavones showed significant effects on headache (three studies, 340 participants, Hedges' g = -0.38, 95% CI [-0.60 to -0.17], p = 0.00)
Effect
Beneficial
Effect size
Moderate
Soy→Reduced Hot Flash
no significant treatment effect on ... hot flushes
Effect
Neutral
Effect size
Small
Soy→Reduced Insomnia
no significant treatment effect on ... insomnia
Effect
Neutral
Effect size
Small
Soy→Reduced Menopausal Symptoms
soy isoflavones were effective for treating menopausal symptoms (seven studies, 533 participants, Hedges' g = -0.25, 95% CI [-0.42 to -0.08], p = 0.00)
Effect
Beneficial
Effect size
Small
Soy→Reduced Palpitation
palpitation (three studies, 356 participants, Hedges' g = -0.42, 95% CI [-0.63 to -0.22], p = 0.00)
Effect
Beneficial
Effect size
Moderate
Soy→Reduced Palpitation Symptoms
palpitation (three studies, 356 participants, Hedges' g = -0.42, 95% CI [-0.63 to -0.22], p = 0.00)
Effect
Beneficial
Effect size
Moderate
Soy→Reduced Paresthesia Symptoms
no significant treatment effect on paresthesia symptoms
Effect
Neutral
Effect size
Small
Soy→Reduced Physical Symptoms
no significant treatment effect on ... physical symptoms
Effect
Neutral
Effect size
Small
Soy→Reduced Psychosocial Symptom
psychosocial symptoms (five studies, 416 participants, Hedges' g = -0.29, 95% CI [-0.48 to -0.10], p = 0.00)
Effect
Beneficial
Effect size
Small
Soy→Reduced Vasomotor Symptom
no significant treatment effect on paresthesia symptoms, fatigue symptoms, physical symptoms, hot flushes, excessive sweating, insomnia, and vasomotor symptoms was observed
Effect
Neutral
Effect size
Small