While the vast majority of these supplements are basically safe, as with anything, both good and bad can result from their consumption. Always keep your physician or pharmacist informed about any herbal products you may be taking.

Saw palmetto was recently featured in "Consumer's Reports" as a remedy for men with prostate problems, specifically for Benign Prostatic Hyperplasia or BPH.

Saw palmetto, or serenoa repens, is related to palm trees and grows predominantly in the Southeast. It produces a small brownish-black berry which contains the active ingredients used in the supplement.

Saw palmetto falls into a category containing only a very few herbals, in which there is good evidence it might actually be helpful. It is not a cure for BPH, however. It may only help to relieve some symptoms.

BPH is an enlargement of the prostate gland, primarily resulting from the effects of male hormones. It is common in older men and, if you live to be 80, you are almost assured of having BPH. Researchers are not sure how saw palmetto works but it possibly interferes with hormone production causing the prostate to enlarge.

Saw palmetto has been reported in numerous studies to be somewhat effective in decreasing the symptoms of BPH, with the palmetto berry or lipophilic extract showing the most promise. In these studies, the extract used contained 80-90 percent fatty acids and may need to be taken for at least two months before improved urine flow is noticed. The saw-palmetto herbal blend is not effective.

Side effects of the herb include headache and diarrhea. It will not lower PSA (prostate-specific antigen) levels. Even though saw palmetto has been used in the past to increase breast size, among other things, its use by women is not recommended due to a possible interaction with birth-control pills and hormone therapy, and its contraindication during breast-feeding.

But my continued concerns are:

* Good quality sources of herbal supplements can be tricky to find;

* Saw palmetto should not be used until a definitive diagnosis is made by a physician.

Since BPH and prostate cancer symptoms are similar, cancer must be ruled out first. I repeat, do not start on saw palmetto without first ruling out prostate cancer.

Of 13 brands of saw palmetto tested by Consumer Reports, only eight contained the stated amount claimed on the label.

If you are determined to try saw palmetto, first clear it with your doctor, then check out the Web site consumerlab.com, which does independent testing on various brands of herbal supplements.

Consumer Lab found problems with 10 of 27 samples. They, along with "Consumer Reports," are the closest thing we have to a Food and Drug Administration to test herbs on the market.

(Editor's Note: Almquist is the pharmacy chief at the Madigan Army Medical Center, Wash.)