Saw palmetto for prostate disorders -- american family physician
Saw Palmetto for Prostate Disorders
ANDREA E. GORDON, M.D., and ALLEN F. SHAUGHNESSY, PHARM.D.
Harrisburg Family Practice Residency, Harrisburg, Pennsylvania
Saw palmetto is an herbal product used in the treatment of symptoms related to
benign prostatic hyperplasia. The active component is found in the fruit of the Amer-
ican dwarf palm tree. Studies have demonstrated the effectiveness of saw palmetto in
reducing symptoms associated with benign prostatic hyperplasia. Saw palmetto
appears to have efficacy similar to that of medications like finasteride, but it is better
tolerated and less expensive. There are no known drug interactions with saw pal-
metto, and reported side effects are minor and rare. No data on its long-term usage
are available. The herbal product also has been used to treat chronic prostatitis, but
currently there is no evidence of its efficacy. (Am Fam Physician 2003;67:1281-3. Copy-
right 2003 American Academy of Family Physicians.)
not fully understood. Some of the mecha-nisms proposed include anti-inflammatoryactivity,2 blocked conversion of testosterone to
Saw palmetto,also known as Serenoa
or Sabal serrulatum
, is anherb that is most commonly usedto treat problems related to benign
dihydrotestosterone (DHT),3,4 and prostate
epithelial involution similar to effects noted
medicinal element of saw palmetto is taken
from the partially dried ripe fruit of the
Relief of Symptoms
American dwarf palm tree, which is indige-nous to the coastal regions of the southern
United States, from the Carolinas and Florida
their effect on symptoms such as diminished
urine stream, post-void dribbling, overflow
BPH is a nearly universal result of the aging
incontinence, and urinary retention, or by less
process in men. As the prostate gland enlarges,
it can cause both obstructive and irritative
changes in prostate size, and residual volume.
symptoms; however, the size of the prostate
In a Cochrane Review, investigators conducted
gland is not predictive of the symptoms that
studies comparing saw palmetto with placebo
Saw palmetto is widely used in other coun-
or other drugs.6 [Evidence level A: systematic
tries; for example, it is used in 50 percent of
review of randomized controlled trials RCTs]
treatments for BPH in Italy and in 90 percent of
The review combined the results of 21 trials with
such treatments in Germany.1 The active part
durations of four to 48 weeks. The 21 studies
of the plant is the sterols and free fatty acids
included a total of 3,139 men with a mean age
found in the berry. The particular solvent used
of 65 years (range: 40 to 88 years). According to
in the extraction process affects the resulting
the International Prostate Symptom Scale,
formulation of the product. The most widely
studied form of saw palmetto is Permixon,
average urologic score of 14.4 points out of a
which uses the solvent hexane; other formula-
tions have used ethanol, methanol, and liquid
from eight to 19).6 In the 13 studies that
carbon dioxide as solvents. Historically, saw
palmetto was administered with nettle root and
improved symptom scores, individual symp-
toms, and flow measures more than placebo.
Patients and physicians were more likely to
See page 1226 fordefinitions of strength-
most active, and the mechanism of action is
palmetto treatment than with placebo. In the
palmetto has not been compared with surgical
approaches in the treatment of BPH. Saw pal-
Key Points About Saw Palmetto
metto is also widely used for treatment ofchronic prostatitis, although scientific evi-
Treatment of chronic prostatitis: evidence lacking
Contraindications, Adverse Effects,
Mild gastrointestinal distress: infrequent
Not known to interfere with the diagnosis of prostate cancer
Varies; most studies have used 160 mg twice daily or 320 mg
humans is gastrointestinal distress, which is
mild and can be minimized by taking saw pal-
$6 to $20 per month, depending on brand, for a dosage
metto with food. Saw palmetto is believed to
be quite safe, although formal toxicology
Safe herbal medicine; effective for treatment of symptoms
studies have not been completed. One study8
found no mutagenic or teratogenic effects inrats and dogs that were fed saw palmetto in a
BPH = benign prostatic hyperplasia.
dosage of 2 g per kg daily for six months, andthis dosage was well tolerated. No clinicallyrelevant changes in laboratory parameters
12 studies that reported nocturia results, saw
have been found in human clinical trials.9
palmetto reduced nocturia by 25 percent com-
There has been some concern that saw pal-
metto could mask prostate cancer by lowering
In two studies, saw palmetto and finasteride
prostate-specific antigen (PSA) levels. How-
had similar positive effects on urinary symp-
tom scores and peak urine flow. Adverse effects
1,000 patients did not demonstrate this effect
caused by saw palmetto were mild and infre-
on PSA levels. The same study showed that
quent and comparable to side effects from
finasteride decreased PSA levels by 41 percent.
placebo. Withdrawal rates among patientsreceiving placebo, saw palmetto, and finasteride
were 7.1, 8.9, and 9.0 percent, respectively.
Clinical studies have used a dosage of 160 mg
twice daily or 320 mg once daily of a lipophilic
extract containing 80 to 90 percent of the
volatile oil. A daily dosage of 480 mg was notfound to be any more effective in a six-monthstudy of dosages.8 Teas are not considered tobe effective because they do not contain the
volatile oils. The whole berries can be used at
ANDREA E. GORDON, M.D., is on the faculty of the Harrisburg Family Practice Resi-
the recommended dosage of 1 to 2 g daily.11 As
dency, Harrisburg, Pa. She received her medical degree from Jefferson Medical College
in Philadelphia. Dr. Gordon completed a family practice residency program at the Uni-versity of Connecticut, Hartford, and a fellowship in family practice faculty develop-
ment at St. Margaret Memorial Hospital, Pittsburgh, Pa. She is currently enrolled in an
because of the lack of standardization of such
integrative medicine fellowship at the University of Arizona, Tucson.
ALLEN F. SHAUGHNESSY, PHARM.D., is director of research and associate director of
the Harrisburg Family Practice Residency. He completed his doctorate and fellowship
monly available for purchase may not be the
training at the Medical University of South Carolina, Charleston.
same as those used in clinical studies and,
Address correspondence to Andrea E. Gordon, M.D., Harrisburg Family Practice Resi-
therefore, may not produce the same results.
dency, 2501 N. Third St., Harrisburg, Pa., 17110-2098 (e-mail: [email protected]). Reprints are not available from the authors.
There are no known drug interactions with
saw palmetto. The cost for typical saw pal-
rat ventral prostate. Br J Pharmacol 1984;83
4. Marks LS, Hess DL, Dorey FJ, Macairan ML, Cruz
month at a dosage of 160 mg twice daily.
Santos PB, Tyler VE. Tissue effects of saw palmettoand finasteride: use of biopsy cores for in situ
quantification of prostatic androgens. Urology2001;57:999-1005.
Saw palmetto is an effective treatment for
5. Marks, LS, Partin AW, Epstein JI, Tyler VE, Simon I,
Macairan ML, et al. Effects of a saw palmetto
effective as finasteride and is better tolerated,
herbal blend in men with symptomatic benign pro-static hyperplasia. J Urol 2000;163:1451-6.
less expensive, and less likely to decrease PSA
6. Wilt T, Ishani A, MacDonald R. Serenoa repens for
levels. No research has evaluated the effect of
benign prostatic hyperplasia. Cochrane Database
7. Gerber GS, Kuznetsov D, Johnson BC, Burstein JD.
patients with BPH. Table 1
reviews the efficacy,
Randomized, double-blind, placebo-controlled trial
safety, tolerability, and cost of saw palmetto.
of saw palmetto in men with lower urinary tractsymptoms. Urology 2001;58:960-4.
The authors indicates that they do not have any con-
8. Small JK, Bombardelli E, Morazzoni P. Serenoa
flicts of interest. Source of funding: none reported.
repens (Bartram). Fitoterapia 1997;68:99–113.
9. Plosker GL, Brogden RN. Serenoa repens (Per-
mixon). A review of its pharmacology and thera-peutic efficacy in benign prostatic hyperplasia.
1. Di Silverio F, D’Eramo G, Lubrano C, Flammia GP,
Sciarra A, Palma E, et al. Evidence that Serenoa
10. Carraro JC, Raynaud JP, Koch G, Chisholm GD, Di
repens extract displays an antiestrogenic activity in
Silverio F, Teillac P, et al. Comparison of phytother-
prostatic tissue of benign prostatic hypertrophy
apy (Permixon) with finasteride in the treatment of
benign prostate hyperplasia: a randomized interna-
2. Lowe FC, Ku JC. Phytotherapy in treatment of
tional study of 1,098 patients. Prostate 1996;29:
benign prostatic hyperplasia: a critical review. Urol-
11. Saw palmetto monograph. The Natural Medicines
3. Briley M, Carilla E, Roger A. Inhibitory effect of Per-
Comprehensive Database. www.naturaldatabase.
mixon on testosterone 5a-reductase activity of the
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DIRECTIONS FOR USE PRECAUTIONARY STATEMENTS It is a violation of Federal law to use this product in a manner inconsistent with its CAUTION: READ THIS LABEL and follow all use directions and use precautions. IMPORTANT: Do not expose children, pets or other nontarget animals to animals and pets. May be harmful if swallowed or absorbedthrough the skin because it may reduce the clottin