Saw palmetto hair loss, free ebook for Windows. How the ancient herb saw palmetto has become the leading natural hair loss treatment. The use of saw palmetto for hair loss is often marketed as a more affordable cure and one with fewer side effects. It is said to be effective since saw palmetto can prevent certain testosterone derived chemicals from restricting hair growth. This is similar to the method of action used by finasteride, one of the two approved hair loss treatments by the FDA. Pills containing saw palmetto are among the most widely known and accepted natural forms to block DHT.