It is debated, most of those studies are made in-vitro using really poorly designed assays. Clinical studies in humans don't really show that estrogenic effect,

It is debated, most of those studies are made in-vitro using really poorly designed assays. Clinical studies in humans don't really show that estrogenic effect, even with high doses of extracts processed in various ways. So reasearchers have mostly extrapolated what they saw in a tube with a pure compound to what may happen in a plant extract that contains thousands of time less what they did put in their tube directly in contact with cells sensitive to those compounds... The effects seen may also simply be associated to the sedative properties (which are only really present in fresh hops, old hops cones don't work as well). But I have yet to see a report of estrogenic effects in a human having consumed an extract.