Estradiol

<p>Grape seed extract is also an <a href="http://en.wikipedia.org/wiki/Aromatase_inhibitor" title="Aromatase inhibitor">aromatase inhibitor</a> <i><a href="http://en.wikipedia.org/wiki/In_vitro" title="In vitro">in vitro</a></i>,<sup id="cite_ref-21" class="reference"><a href="http://en.wikipedia.org/wiki/Grape_seed_extract#cite_note-21">[21]</a></sup> i.e. it may suppress the conversion of <a href="http://en.wikipedia.org/wiki/Testosterone" title="Testosterone">testosterone</a> to <a href="http://en.wikipedia.org/wiki/Estradiol" title="Estradiol">estradiol</a>.</p>