Dangerous, I don't trust the health system. Besides that these pills are like castration. Use a damn condom!
Here is my advice for high fertility for men:
-No more hot baths
-Lift weights
-Stop eating soy and drinking hop
-Stop eating sugar and processed foods
-Use the car less
-Check your testosterone levels
-Use Creatin, Vitamine D3, Magnesium and Zinc
-Fix your sleep rhythm and reduce stress whatever it takes (this here is the most important as permanent high cortisol level will make you fat and reduce your testosterone and sperm levels).
do you use this system before why you are saying dangerous?