Natural estrogen's blocker is suggested by NutritionFacts.org Dr Greger who is a Vegan but will you follow him using plant base food, he shows you research papers but not sure if they do trials like the pharma do when they develop drugs. Really not sure, the world is pro pharma who at the end produce drugs that save lives and makes tons of money but you have to spend more money on side effects, rather producing drugs with natural ingredients which has no side effects so we don't need to spend more money to buy drugs to treat side effects!