Saw palmetto is a native plant of North America, and it is still primarily grown in the United States.

The saw palmetto tree grows only about 2 to 4 feet high, with fan-shaped serrated leaves and abundant berries. Native Americans used these berries for the treatment of various urinary problems in men, as well as for women with breast disorders. European and American physicians took up saw palmetto as a treatment for benign prostatic hyperplasia (BPH). In the 1960s, French researchers discovered that by concentrating the oils of saw palmetto berry they could maximize the herb's effectiveness.

Saw palmetto contains many biologically active chemicals. Unfortunately, we don't know which ones are the most important. We also don't really know how saw palmetto works; it appears to interact with various sex hormones, but it also has many other complex actions that could affect the prostate.

Saw palmetto oil is an accepted medical treatment for benign prostatic hyperplasia (BPH) in New Zealand and in France, Germany, Austria, Italy, Spain, and other European countries.

Typical symptoms of BPH include difficulty starting urination, weak urinary stream, frequent urination, dribbling after urination, and waking up several times at night to urinate. Most, thought not all, research suggests that saw palmetto can markedly improve all these symptoms. Benefits require approximately 4 to 6 weeks of treatment to develop. It appears that about two-thirds of men respond reasonably well.

Furthermore, while the prostate tends to continue to grow when left untreated,1saw palmetto causes a small but definite shrinkage.2-4 In other words, it isn't just relieving symptoms, but may actually be delaying prostate enlargement. The drug Proscar does this too (and to a greater extent than saw palmetto) but other standard medications for BPH have no effect on prostate size.

Some studies suggest that saw palmetto is equally effective for reducing BPH symptoms as Proscar, and it has one meaningful advantage: It leaves PSA (prostate-specific antigen) levels unchanged. Cancer raises PSA levels, and lab tests that measure PSA are used to screen for prostate cancer. Proscar lowers PSA measurements, and therefore, its use may have the unintended effect of masking prostate cancer. Saw palmetto won't do this. On the other hand, Proscar has been shown to reduce the need for surgery, unlike saw palmetto or any of the other drugs used for BPH.

Saw palmetto may also be equally as effective as another class of standard drugs known as alpha blockers, but may cause fewer side effects.

Note: Before self-treating with saw palmetto, be sure to get a proper medical evaluation to rule out prostate cancer.

Saw palmetto is also widely used to treat chronic prostatitis. Anopentrial that compared saw palmetto to the drug Proscar for the treatment of chronic nonbacterial prostatitis found that while the drug was effective, the herb was not.5 However, these results do not mean that saw palmetto is ineffective for prostatitis. Because this was an open study, researchers and participants knew who was getting saw palmetto and who was getting the drug. If there was any expectation that the drug would be more powerful than the herb, this in itself would be sufficient to skew the results toward that outcome.

Saw palmetto is sometimes recommended as a treatment for hair loss, but there is no evidence at all that it is effective for this purpose.