Saw Palmetto (Serenoa repens [Bartram] Small)

Saw Palmetto (Serenoa repens [Bartram] Small)

Background

Saw palmetto ( Serenoa repens, Sabal serrulata ) is used popularly in Europe for symptoms associated with benign prostatic hypertrophy (enlargement of the prostate). Although not considered standard of care in the United States, it is the most popular herbal treatment for this condition.

Historical use of saw palmetto can be traced in the Americas to the Mayans who used it as a tonic, and to the Seminoles who took the berries as an expectorant and antiseptic.

Saw palmetto was listed in the United States Pharmacopeia from 1906 to 1917, and in the National Formulary from 1926 to 1950. Saw palmetto extract is a licensed product in several European countries.

Multiple mechanisms of action have been proposed, and saw palmetto appears to possess 5-α-reductase inhibitory activity (thereby preventing the conversion of testosterone to dihydrotestosterone). Hormonal/estrogenic effects have also been reported, as well as direct inhibitory effects on androgen receptors and anti-inflammatory properties.

Synonyms

American dwarf palm tree, Arecaceae (family) , cabbage palm, dwarf palm, Elusan® Prostate, IDS 89, LSESR, PA 109, Palmae (family), palmetto scrub, palmier de l' amerique du nord, palmier nain, Permixon®, Prostagutt®, Prostaserine®, sabal, Sabalfruchte (German), Sabal fructus , savpalme (Danish), saw palmetto berryserenoa, Serenoa serrulata Hook F., SG 291, Strogen®, WS 1473, Zwegpalme.

Also see information on pygeum ( Prunus africanum, Pygeum africanum ) .

Evidence

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Uses based on scientific evidenceGrade*Enlarged prostate (benign prostatic hypertrophy/BPH)
Numerous human trials report that saw palmetto improves symptoms of benign prostatic hypertrophy (BPH) such as nighttime urination, urinary flow, and overall quality of life, although it may not greatly reduce the size of the prostate. The effectiveness may be similar to the medication finasteride (Proscar®) with fewer side effects. Although the quality of these studies has been variable, overall they suggest effectiveness. Saw palmetto has not been thoroughly compared to other types of drugs used for BPH, such as doxazosin (Cardura®) or terazosin (Hytrin®). Most available studies have assessed the standardized saw palmetto product Permixon®. Although a 2003 study by Willetts et al. reports no difference between the effects of saw palmetto and placebo in 100 men over a 12-week period, overall the weight of available scientific evidence favors the effectiveness of saw palmetto.

A

Male-pattern hair loss
It has been suggested that saw palmetto may block some effects of testosterone and therefore reduce male pattern hair loss, similar to the medication finasteride (Propecia®). More studies are necessary before saw palmetto can be recommended for this use.

C

Underactive bladder
There is currently little information on the effectiveness of saw palmetto for the treatment of bladder disorders.

C

Prostatitis/chronic pelvic pain syndrome (CP/CPPS)
A prospective, randomized, open label, 1-year study was designed to assess the safety and efficacy of saw palmetto and finasteride in the treatment of men diagnosed with category III prostatitis/chronic pelvic pain (CP/CPPS). CP/CPPS treated with saw palmetto had no appreciable long-term improvement. In contrast, patients treated with finasteride had significant and durable improvement in multiple parameters except for voiding.

D

* Key to grades
A: Strong scientific evidence for this use;
B: Good scientific evidence for this use;
C: Unclear scientific evidence for this use;
D: Fair scientific evidence against this use (it may not work);
F: Strong scientific evidence against this use (it likely does not work).

Uses based on tradition or theory
The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Acne, aphrodisiac, asthma, bladder inflammation, breast feeding, breast enlargement or reduction, bronchitis, cancer, cough, cystitis, diabetes, digestive aid, diarrhea, diuretic, dysentery, excess hair growth, expectorant, high blood pressure, hormone imbalances (estrogen or testosterone), immune stimulation, impotence, indigestion, inflammation, lactation stimulation, laryngitis, libido, menstrual pain, migraine headache, muscle or intestinal spasms, ovarian cysts, polycystic ovarian syndrome, postnasal drip, prostate cancer, reproductive organ problems, sedation, sexual vigor, sore throat, sperm production, testicular atrophy, upper respiratory tract infection, urethritis, urinary antiseptic, uterine or vaginal disorders.

Dosing

The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Standardization

Standardization involves measuring the amount of certain chemicals in products to try to make different preparations similar to each other. It is not always known if the chemicals being measured are the "active" ingredients. A standardized extract of saw palmetto containing 80% to 95% sterols and fatty acids (liposterolic content) is often recommended.

One small study examining amounts of saw palmetto contained in preparations compared to amounts stated on labels reported a -97% to +140% difference compared to label claims. Half of the samples (3 samples) contained less than 25% of the stated amounts. Although this study examined very few saw palmetto products, it is a noteworthy example of limited quality assurance.

Adults (18 years and older)

Oral (by mouth) : For enlarged prostate (benign prostatic hypertrophy), a dose of 320 milligrams daily, in one dose or two divided doses (80% to 90% liposterolic content), has been used in numerous studies. Reports suggest that 160 milligrams once daily may be as effective as twice daily. Traditional or other suggested doses that are less studied include: 1 to 2 grams of ground, dried, or whole berries daily; 2 to 4 milliliters of tincture (1:4) three times daily; 1 to 2 milliliters fluid extract of berry pulp (1:1) three times daily; or tea (2 teaspoons dried berry with 24 ounces water, simmered slowly until liquid is reduced by half) taken as 4 ounces three times daily. Teas prepared from saw palmetto berries are potentially not as effective because the active ingredients may not dissolve in water. Some experts believe that a preparation called lipidosterolic extract of Serenoa repens (LSESR) may cause fewer side effects.

Rectal (suppositories) : For enlarged prostate (benign prostatic hypertrophy), limited research reports that rectal saw palmetto (640 milligrams once daily) extract is as effective as 160 milligrams taken by mouth four times daily.

Children (younger than 18 years)

Not enough information is available to recommend the use of saw palmetto in children.

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Allergies

Few allergic symptoms have been reported with saw palmetto. A study of people taking the combination product PC-SPES® (no longer commercially available), which includes saw palmetto and 7 other herbs, reports that 3 out of 70 people developed allergic reactions. In one case, the reaction included throat swelling and difficulty breathing.

Side Effects and Warnings

Few severe side effects of saw palmetto are noted in the published scientific literature. The most common complaints involve the stomach and intestines, and include stomach pain, nausea, vomiting, bad breath, constipation, or diarrhea. Stomach upset caused by saw palmetto may be reduced by taking it with food. Some reports suggest that there may be less abdominal discomfort with the preparation lipidosterolic extract of Serenoa repens (LSESR) . A small number of reports describe ulcers or liver damage and yellowing of the skin (jaundice), but the role of saw palmetto is not clear in these cases. Similarly, reports of headache, dizziness, insomnia, depression, breathing difficulties, muscle pain, high blood pressure, chest pain, abnormal heart rhythm, and heart disease have been reported, but are not clearly caused by saw palmetto. People with health conditions involving the stomach, liver, heart, or lungs should use caution.

At least two case reports describe severe bleeding during saw palmetto use. Caution is advised in people scheduled to undergo some surgeries or dental work, who have bleeding disorders, or who are taking drugs that may increase the risk of bleeding. Dosing adjustments may be necessary. Several reports describe men with prostate cancer who developed blood clots in the legs and lung while taking saw palmetto. Since cancer may increase the risk of blood clots, it is not clear if saw palmetto was the cause.

Some men using saw palmetto report difficulty with erections, testicular discomfort, breast tenderness or enlargement, and changes in sexual desire. Saw palmetto may have effects on the body's response to the sex hormones estrogen and testosterone, but no specific effect has been well demonstrated in humans. Men or women taking hormonal medications (such as finasteride/Proscar®/Propecia® or birth control pills) or who have hormone-sensitive conditions should use caution. Tinctures may contain high levels of alcohol and should be avoided when driving or operating heavy machinery.

In theory, PSA (prostate specific antigen) levels may be artificially lowered by saw palmetto, based on a proposed mechanism of action of saw palmetto (inhibition of 5-α-reductase). Therefore, there may be a delay in diagnosis of prostate cancer, or interference with following PSA levels during treatment or monitoring in men with known prostate cancer.

The combination product PC-SPES®, which contains saw palmetto and 7 other herbs, has been found to contain prescription drugs including warfarin, a blood thinner. The U.S. Food and Drug Administration has issued a warning not to use PC-SPES® for this reason, and it is no longer commercially available.

Pregnancy and Breastfeeding

Because of possible hormonal activity, saw palmetto extract is not recommended for women who are pregnant or breast-feeding. Many tinctures contain high levels of alcohol, and should be avoided during pregnancy.

References

1. Boyle P, Robertson C, Lowe F, et al. Meta-analysis of clinical trials of Permixon in the treatment of symptomatic benign prostatic hyperplasia. Urology 2000;55(4):533-539.

2. Braeckman J, Bruhwyler J, Vanderkerckhove K, et al. Efficacy and safety of the extract of in the treatment of benign prostatic hyperplasia: therapeutic equivalence between twice and once daily dosage forms. Phytother Res 1997;11:558-563.

3. Braeckman J. A double-blind, placebo-controlled study of the plant extract in the treatment of benign hyperplasia of the prostate. Eur J Clin Res 1997;9:247-259.

4. de la TA, Buttyan R, Hayek O, et al. Herbal therapy PC-SPES: in vitro effects and evaluation of its efficacy in 69 patients with prostate cancer. J Urol 2000;164(4):1229-1234.

5. Descotes J, Rambeaud J, Deschaseaux P, et al. Placebo-controlled evaluation of the efficacy and tolerability of Permixon in benign prostatic hyperplasia after exclusion of placebo responders. Clin Drug Invest 1995;9(5):291-297.

6. Feifer AH, Fleshner NE, Klotz L. Analytical accuracy and reliability of commonly used nutritional supplements in prostate disease. J Urol 2002;168(1):150-154; discussion 154.

7. Gerber GS, Kuznetsov D, Johnson BC, et al. Randomized, double-blind, placebo-controlled trial of saw palmetto in men with lower urinary tract symptoms. Urology 2001;58(6):960-964.

8. Gordon AE, Shaughnessy AF. Saw palmetto for prostate disorders. Am Fam Physician 2003;67(6):1281-1283. Review.

9. Kaplan SA, Volpe MA, Te AE. A prospective, 1-year trial using saw palmetto versus finasteride in the treatment of category III prostatitis/chronic pelvic pain syndrome. J Urol 2004;171(1):284-288.

10. Markowitz JS, Donovan JL, Devane CL, et al. Multiple doses of saw palmetto (Serenoa repens) did not alter cytochrome P450 2D6 and 3A4 activity in normal volunteers. Clin Pharmacol Ther 2003;74(6):536-542.

11. Oh WK, George DJ, Hackmann K, et al. Activity of the herbal combination, PC-SPES, in the treatment of patients with androgen-independent prostate cancer. Urology 2001;57(1):122-126.

12. Pfeifer BL, Pirani JF, Hamann SR, et al. PC-SPES, a dietary supplement for the treatment of hormone-refractory prostate cancer. BJU Int 2000;85(4):481-485.

13. Shoskes DA. Phytotherapy and other alternative forms of care for the patient with prostatitis. Curr Urol Rep 2002;3(4):330-334.

14. Small EJ, Frohlich MW, Bok R, et al. Prospective trial of the herbal supplement PC-SPES in patients with progressive prostate cancer. J Clin Oncol 2000;18 (21) :3595-3603.

15. Talpur N, Echard B, Bagchi D, et al. Comparison of Saw Palmetto (extract and whole berry) and Cernitin on prostate growth in rats.Mol Cell Biochem 2003;250(1-2):21-26.

16. Veltri RW, Marks LS, Miller MC, et al. Saw palmetto alters nuclear measurements reflecting DNA content in men withsymptomatic BPH: evidence for a possible molecular mechanism.Urology 2002;60(4):617-622.

17. Willetts KE, Clements MS, Champion S, et al. Serenoa repens extract for benign prostate hyperplasia: a randomized controlled trial. BJU Int 2003;92(3):267-270.

18. Wilt TJ, Ishani A, Stark G, et al. Saw palmetto extracts for treatment of benign prostatic hyperplasia: a systematic review. JAMA 1998;280(18):1604-1609.

January 01, 2004