α-Zearalenol is a nonsteroidal estrogen of the resorcylic acid lactone group related to mycoestrogens found in Fusarium spp.[1] It is the α-epimer of β-zearalenol. Along with β-zearalenol, it is a major metabolite of zearalenone formed mainly in the liver but also to a lesser extent in the intestines during first-pass metabolism.[2] [3] A relatively low proportion of β-zearalenol is metabolized from zearalenone compared to α-zearalenol in humans. α-Zearalenol is about three to four times more potent as an estrogen relative to zearalenone.