Saw palmetto does not appear to affect levels of prostate-specific antigen. Prostate-specific antigen, or PSA, is a protein created by the prostate that may indicate prostate cancer, prostatitis or an enlarged prostate, according to WebMD.
Saw palmetto is a fruit primarily used to treat various urinary issues related to the prostate, as well as decreased sex drive, hair loss and hormone imbalances. Saw palmetto is used whole, dried, ground and in liquid extracts and tablets. While a handful of small studies have linked saw palmetto to effective treatment of benign prostatic hyperplasia, scientific evidence remains inconclusive, according to WebMD. Saw palmetto causes stomach discomfort in some patients.