I've had this discussion with many people in the past with products such as JW and BAM. When you are "prone or predisposed" to gyno, it's almost a crap shoot when using any products that are intended to increase or decrease hormone levels. I would think the timeframe you would be concerned with would be afterwards. If a product controls or reduces estrogen levels, one has to worry in your case about the potential of rebound effect afterwards. I'm not saying you would have this effect, just something I would think about if you are predisposed to gyno related issues. That's my 2 cents anway, maybe someone else can jump in on this topic.