Penaril is marketed as a male enhancement supplement designed to improve sexual performance, boost libido, and increase stamina. As with many products in this category, it claims to help men overcome common issues such as low testosterone, poor blood... morePenaril is marketed as a male enhancement supplement designed to improve sexual performance, boost libido, and increase stamina. As with many products in this category, it claims to help men overcome common issues such as low testosterone, poor blood circulation, and decreased libido, which can all contribute to a less satisfying sex life. With so many options on the market, it can be difficult to determine which products are actually effective.