Table 5.

Effects of isoflavones in menopausal symptoms.

Authors	Number of Studies Included	Type of Studies Included	Number of Participants and Gender/Age/Characteristics	Compound and Doses	Observed Effects
Meta-analysis
Chen et al., 2015 [86]	15	RCT	30–252 perimenopausal or postmenopausal women/report (1753 in total) 49–58.3 years (placebo group) 48–60.1 years (phytoestrogen group)	Isoflavones 5–100 mg/day Intervention period: 3–12 months	Reduction of hot flush frequency (vs. placebo)
Li et al., 2015 [87]	16	RCT	24–236 women/report (median 90) 40–65 years	Soy isoflavones 30–200 mg/day Intervention period: 4 weeks–2 years (median 12 weeks)	Slight and slow attenuation of hot flushes (vs. estradiol)
Li et al., 2016 [88]	39	RCT	24–620 women/report (median 200) Age not available	SSRIs/SNRIs: 7.5–200 mg/day Gabapentin: 300–1800 mg/day Clonidine: 0.1–0.4 mg/day Soy isoflavones: 30–200 mg/day Intervention period: 2–96 weeks (average 12 weeks)	Slight and slow attenuation of hot flushes (vs. non-hormonal drugs)
Daily et al., 2019 [85]	5	RCT	728 menopausal women (total subjects) 50.5–58.8 years (mean)	Soy isoflavones: 33–200 mg/day and 6 g soy extract/day Equol: 10 mg/day Intervention period: not available	Equol or isoflavone in equol-producers more effective than placebo
Sarri et al., 2017 [89]	32	RCT	4165 menopausal women (total subjects) 45+ years	Isoflavones and black cohosh (Doses not available)	Reduction of VSM (hot flushes and night sweats) compared to placebo No beneficial effect (vs. pharmacological treatment)
Franco et al., 2016 [90]	17	RCT	30–252 women/trial 40–69 years	Dietary soy isoflavones: 42–90 mg/day Supplements and extracts of soy isoflavones: 10–100 mg/day Red clover: 40–160 mg/day Intervention period: 12–48 weeks	Reduction of hot flush frequency by means of dietary isoflavones and supplements) Reduction of night sweat frequency by red clover
Systematic reviews
Chen et al., 2019 [86]	15	RCT (9) Prospective study (2) Systematic review (2) Randomized crossover trial (1) Meta-analysis (2)	51–403 menopausal and postmenopausal women	Soy (soy nut, soy protein, soy extracts) Natural isoflavones Synthetic isoflavones	Beneficial effects of isoflavones (vs. placebo) Synthetic or combination of isoflavones more effective than natural soy HRT more effective than soy or its extracts Isoflavone in equol-producers or equol supplementation more effective than placebo.
Perna et al., 2016 [52]	7	RCT	40–403 menopausal and postmenopausal women	Isoflavones 50–120 mg/day Intervention period: 8 weeks–2 years	Reduction of hot flush frequency

HRT: hormone replacement therapy, RCT: randomized controlled trial, VSM: vasomotor symptoms.