These are oestrogenic substances extracted from plant organisms.

Function

Woodside (2006) notes an increase in blood levels of IGF-1 in women following supplementation with plant phytoestrogens.

Negative notes

In women there are no known adverse effects, but male athletes are not recommended to take it.

Form and posology

They are commercially available in tablet form. In the Woodside study, 80mg doses were used.