Geem,the market is full of 'duds' because of good marketing.
Have a look at the Penis enlargement pills market ( do you get any spam in your email inbox ??) it is worth millions. Now, that's a King Dud !
Pepp it's clinically proven to work , but like every other medicine or vitamins it effect people in different ways.
Problem with this product : highly controversial.
My 2 cents worth