S-Equol

3 studies · 2 supporting · 1 against

How it was tested: The soy metabolite equol is classified as 'not recommended' for vasomotor symptoms (Level I-II evidence) - a position that predates or does not fully account for the equol-producer-vs-nonproducer trial evidence.

S-equol is a more potent and more selective estrogen-receptor-beta agonist than the isoflavones it is derived from, but only reaches meaningful blood levels in people whose gut bacteria can perform the conversion (or who take it directly as a supplement, bypassing that requirement).

Dose: 10–40 mg

Tested as: S-equol (natural, soy-fermentation-derived; e.g. SE5-OH), 10 mg or 40 mg/day, generally tested against soy isoflavones rather than placebo alone. Benefit is concentrated in equol nonproducers - roughly 70-80% of Western women, whose gut bacteria cannot convert the soy isoflavone daidzein into equol.