In this first study, researchers orally administered black pepper to male mice. They found that 0.5mg (the equivalent of 1 - 2 grams of black pepper per day in humans) was enough to induce testicular damage and resulted in a reduced litter size. The second study, researchers administered raw garlic and found that the rat germ cells (meaning the things that become sperm) would die off. This goes along with what we’ve been teaching for many years: many of the foods that are good at killing cancer cells, are good at killing your fertility as well…
 
Indian J Exp Biol. 2009 Sep;47(9):706-14.
Reprod Biol Endocrinol. 2009 Jun 24;7:65.