Serenoa repens, better known as Saw Palmetto, is a plant native to North America. Native Americans have used it for centuries as a tonic, topical cleanser against germs, and to remedy urinary and reproductive disorders in men.  European and American settlers used saw palmetto for a wide range of ailments.
In recent years saw palmetto has been used for BPH (benign prostate hyperplasia). While studies have provided mixed results as to its effectiveness, saw palmetto has proven an option for many men who have BPH, as well as other conditions associated with aging in men. Some of these other conditions include low testosterone levels, erectile response, mood disorders, and male pattern baldness.
How Does Saw Palmetto Work?
Saw palmetto has been shown to inhibit the production of the enzyme 5-alpha reductase.   This enzyme converts the male hormone testosterone into dihydrotestosterone, a potent androgen hormone. While this hormone plays an important role in male development, it also contributes to many of the concerns associated with middle-aged and older men.
The conversion of testosterone by 5-alpha reductase typically occurs in the testes, prostate, adrenal glands and hair follicles. It is in these same areas that men suffer hair loss, prostate enlargement and the factors that lead to loss of libido. By inhibiting and slowing the production of this enzyme, saw palmetto reduces the effects often associated with too much dihydrotestosterone as men age.
Saw Palmetto and Prostate Benefits
There has been a lot of controversy over the effectiveness of saw palmetto when used for BPH and other prostate oriented conditions. A recent 2013 trial found a positive impact of saw palmetto on the symptoms of BPH and sexual dysfunction.  In this particular trial, the patients taking saw palmetto confirmed the effectiveness of the saw palmetto in reducing their symptoms and improving their overall quality of life.
Saw Palmetto and Testosterone Levels
Healthy testosterone levels have been associated with virility, strength and weight management. As saw palmetto inhibits the conversion of testosterone, the body retains higher levels of testosterone for use. A greater presence of testosterone helps regulate body weight, maintain a more positive mood, and encourages better sexual function. 
Saw Palmetto and Urinary Frequency
Saw palmetto has been shown to support the urological system in men who have BPH.  Researchers believe this occurs as a result of an interaction with the receptors in the lower urinary tract that are associated with urinary dysfunction and overactive bladder (OAB). This provides scientific support for its traditional use for urinary concerns.
Saw Palmetto as Protection against Hair Loss
The conversion of testosterone by 5-alpha reductase in the hair follicles has been determined to be the leading cause of male pattern baldness (androgenetic alopecia). By inhibiting the action of this enzyme, saw palmetto may lessen hair loss and stimulate hair growth. Researchers have further observed that saw palmetto extract contributes to hair regrowth. 
When to take Saw Palmetto
While studies have suggested certain medical drugs may be more effective than saw palmetto for addressing prostate or hair related concerns, they have omitted perhaps the biggest advantage of saw palmetto – it's a natural herb and seems to be free of side effects. Have you ever seen a prescription drug that didn't include a long warning label? Me either. Conversely, studies have found little evidence of toxicity in the use of saw palmetto.  Saw palmetto can also be used in coordination with other BPH or male hair growth medicines, although you should always consult with your healthcare provider before combining a supplement with a prescription to determine whether possible unwanted interactions may result.
Saw palmetto remains an excellent option for middle-aged and older men. It fights the creation of androgen hormones associated with male prostate concerns and hair loss. It supports healthy testosterone levels. Ultimately, saw palmetto may help a man protect his sexual function, prostate health and long-term well being.
Have you added saw palmetto to your nutritional program? Please leave a comment and share your experience with us!
- Mayo Clinic. Saw palmetto (Serenoa repens [Bartram] Small). (last accessed 2013-08-05)
- Scaglione F, Lucini V, Pannacci M, Dugnani S, Leone C. Comparison of the potency of 10 different brands of Serenoa repens extracts. Eur Rev Med Pharmacol Sci. 2012 May;16(5):569-74.
- Pais P. Potency of a novel saw palmetto ethanol extract, SPET-085, for inhibition of 5alpha-reductase II. Adv Ther. 2010 Aug;27(8):555-63. doi: 10.1007/s12325-010-0041-6. Epub 2010 Jul 10.
- Suter A, Saller R, Riedi E, Heinrich M. Improving BPH symptoms and sexual dysfunctions with a saw palmetto preparation? Results from a pilot trial. Phytother Res. 2013 Feb;27(2):218-26. doi: 10.1002/ptr.4696. Epub 2012 Apr 23.
- Osvaldo P. Almeida, MD, PhD, FRANZCP; Bu B. Yeap, MBBS, PhD; Graeme J. Hankey, MBBS, MD; Konrad Jamrozik, MBBS, DPhil; Leon Flicker, MBBS, FRACP, PhD. Low Free Testosterone Concentration as a Potentially Treatable Cause of Depressive Symptoms in Older Men FREE. Arch Gen Psychiatry. 2008;65(3):283-289. doi:10.1001/archgenpsychiatry.2007.33.
- Suzuki M, Ito Y, Fujino T, Abe M, Umegaki K, Onoue S, Noguchi H, Yamada S. Pharmacological effects of saw palmetto extract in the lower urinary tract. Acta Pharmacol Sin. 2009 Mar;30(3):227-81. doi: 10.1038/aps.2009.1.
- Rossi A, Mari E, Scarno M, Garelli V, Maxia C, Scali E, Iorio A, Carlesimo M. Comparitive effectiveness of finasteride vs Serenoa repens in male androgenetic alopecia: a two-year study. Int J Immunopathol Pharmacol. 2012 Oct-Dec;25(4):1167-73.
- Avins AL, Lee JY, Meyers CM, Barry MJ; CAMUS Study Group. Safety and toxicity of saw palmetto in the CAMUS trial. J Urol. 2013 Apr;189(4):1415-20. doi: 10.1016/j.juro.2012.10.002. Epub 2012 Oct 9.
†Results may vary. Information and statements made are for education purposes and are not intended to replace the advice of your doctor. If you have a severe medical condition or health concern, see your physician.