Saw palmetto (
Serenoa repens) is an herbal supplement often used for prostate problems. In particular, it is usually used to help relieve the symptoms of an
enlarged prostate (also known as benign prostatic hyperplasia or
BPH).
There are several different ideas about how the supplement might work. One theory suggests that it may work by inhibiting an enzyme called 5-alpha-reductase, blocking the conversion of testosterone into DHT (dihydrotestosterone), thereby decreasing the amount of DHT in the body. Since DHT is important for enlargement of the prostate, this may be how saw palmetto works for BPH. In fact, several prescription medications for enlarged prostate work in a similar way. Since these prescription medications are also effective for hair loss (particularly male pattern baldness), it is possible that saw palmetto may also work for hair loss.
Saw palmetto may also inhibit a few different growth factors (proteins in the body that encourage cell growth) and may also have anti-inflammatory properties. Some researchers think that the supplement may work by slowing down the growth of prostate cells or decreasing inflammation.
Many studies have evaluated the effectiveness of saw palmetto for an enlarged prostate, and the results have been mixed. Some studies indicated that it worked well, while other studies suggested that it was no more effective than a placebo (a "sugar pill" with no active ingredients).
There is not enough evidence to evaluate the effectiveness of the supplement for any other use.
Even though less information is available about the best way to dose herbal supplements, compared to prescription or non-prescription medications, most studies of saw palmetto for an
enlarged prostate used similar doses. Based on these studies, a standard dose can be recommended.
Side Effects of Saw Palmetto
Many people believe that "natural" products, such as saw palmetto, have no side effects. However, many natural products cause side effects, some of which can be quite serious. Saw palmetto can cause side effects such as:
(Click Saw Palmetto Side Effects to learn more, including potentially serious side effects that you should report immediately to your healthcare provider.)
The supplement is probably safe for many people at reasonable doses for short periods of time. However, some people may be more likely to experience problems than others. Therefore, you should talk with your healthcare provider before taking saw palmetto if you:
Make sure to tell your healthcare provider about all other medicines you are taking, including prescription and non-prescription medicines, vitamins, and herbal supplements.
(Click Saw Palmetto Safety for more information, including any available warnings and precautions.)
What If I Take an Overdose?
It is not known exactly what to expect from a saw palmetto overdose. If you think you may have taken too much, seek immediate medical attention.
How Should Saw Palmetto Be Stored?
Refer to the label of your individual saw palmetto product for information on how to best store it. Keep saw palmetto and all other medications or supplements out of the reach of children.
