Pycnogenol, also known as French maritime pine tree bark extract, can increase sperm quality and function in men with fertility problems, according to the U.S. National Library of Medicine. A clinical trial concluded that Pycnogenol therapy improves the morphology and mannose receptor binding qualities of sperm, possibly enabling natural fertilization.
Pycnogenol works by improving blood circulation, stimulating the immune system and providing antioxidant benefits, as stated by WebMD. Peanut skin, grape seed and witch hazel bark also contain the active ingredients in Pycnogenol. In addition to helping with male fertility, Pycnogenol is also used to treat allergies, asthma, high blood pressure and circulation problems.