Natural Standard® Patient Monograph, Copyright © 2014 (www.naturalstandard.com). All Rights Reserved. Commercial distribution prohibited. This monograph is intended for informational purposes only, and should not be interpreted as specific medical advice. You should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.

Background

Saw palmetto (Serenoa repens, Serenoa serrulata) is used popularly in Europe to treat symptoms of enlarged prostate. Although it is not considered the standard of care in the United States, it is the most popular herbal treatment for this condition. More than two million American men use saw palmetto for enlarged prostate, and it is commonly recommended as an alternative treatment by the U.S. Food and Drug Administration (FDA).

Many studies report that saw palmetto may be as effective as the hormonal agent finasteride (Proscar®) and may cause fewer side effects when used to treat bladder problems. Most research has focused on the saw palmetto product Permixon®. However, results are still mixed, and further research is needed.

Saw palmetto has also been used for low sperm count, low sex drive, hair loss, bronchitis, diabetes, inflammation, migraine, and prostate cancer, although there is limited evidence supporting its effectiveness for these conditions.

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.

Adults (18 years and older)

Saw palmetto has been taken as sterol and fatty acid extracts (such as LSESR), berries (ground, dried, whole, or pulp), tincture, fluid extract, or tea. Teas prepared from saw palmetto berries may be ineffective because the purported active constituents are water-insoluble.

For enlarged prostate (benign prostatic hypertrophy), a range of 100-960 milligrams of sabal or Serenoa repens extract has been taken by mouth daily for up to 18 months. A dose of 320 milligrams of saw palmetto extract (e.g., Permixon®, Serendar, Talso®), in one dose or two divided doses (80-90% liposterolic content), by mouth daily for up to six months, has been taken in numerous studies. Dosing regimens of 160 milligrams of saw palmetto twice daily for eight weeks (PA109), nine weeks, and 12 weeks (Prostaserene®) have been taken by mouth. Reports suggest that 160 milligrams once daily by mouth may be as effective as twice daily by mouth. Libeprosta® has been taken as two 80 milligram tablets twice or three times daily by mouth. A dose of 640 milligrams of saw palmetto has also been taken by mouth daily for an unknown length of time. A dose of 640 milligrams of saw palmetto extract has been applied to the rectum once daily for 12 weeks.

In preparation for surgery, pretreatment with 320 milligrams of Serenoa repens (Permixon®) has been taken by mouth daily for at least eight weeks before surgery.

To treat prostate inflammation, 320 milligrams of prostamol (Sabal serrulata plant extract) has been taken by mouth. Also, 320 milligrams of Serenoa repens has been taken by mouth daily for eight weeks.

Children (younger than 18 years)

There is no proven safe or effective dose for saw palmetto in children.

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.

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)

Grading rationale

Evidence gradeCondition to which grade level applies
A

Enlarged prostate

Saw palmetto has been long been used to treat enlarged prostate. According to a report, more than two million American men use saw palmetto for enlarged prostate, and it is often recommended as an alternative therapy by the U.S. Food and Drug Administration (FDA). Many studies report that saw palmetto may be as effective as the hormonal agent finasteride (Proscar®) and may cause fewer side effects when used to treat bladder problems. Most studies used the saw palmetto product Permixon®. Although more recent research failed to find significant benefits of saw palmetto, the available evidence suggests that it may be an effective treatment for enlarged prostate.
C

Hair loss

Saw palmetto may block some hormonal effects and may be an effective treatment for hair loss, with benefits similar to the agent finasteride (Propecia®), when applied to the scalp. Early research suggests that saw palmetto may improve hair density, but evidence is limited at this time. Further research is needed before conclusions can be made.
C

Preparation for surgery (prostate surgery)

Saw palmetto may help the recovery process in patients undergoing prostate surgery. Early research suggests that saw palmetto may improve the effectiveness of surgery, as well as reduce bleeding and duration of catheter use. However, results are conflicting, and more research is needed in this area.
C

Prostate cancer

Saw palmetto is commonly used for many types of prostate problems, including prostate cancer. Research suggests that saw palmetto may block the growth of cancer cells. However, there is limited human research on the effectiveness of saw palmetto for this condition. Evidence is lacking in support of PC-SPES®, a discontinued product that contains saw palmetto, for prostate cancer. The U.S. Food and Drug Administration (FDA) has issued a warning not to use PC-SPES® because it may contain warfarin and alprazolam, which may cause bleeding.
C

Prostate inflammation

There is conflicting evidence on the use of saw palmetto in treating prostate inflammation. Although some studies report that saw palmetto may improve symptoms, obvious benefit over standard drugs is lacking. Much of the research has focused on saw palmetto as part of a combination therapy. Further research is needed to understand the potential effects of saw palmetto alone.
C

Urination

There is limited evidence on the use of saw palmetto to treat underactive bladder. Available studies are low-quality or use saw palmetto in combination with other therapies. More research is needed in this area.

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, asthma, athletic performance enhancement, bacterial infections, bladder inflammation, breast milk stimulant, breast augmentation, breast reduction, bronchitis, clear sinuses, cough, cystitis, diabetes, diarrhea, diuretic, dysentery, Epstein-Barr virus, hair growth (excess), high blood pressure, hormone imbalances (estrogen or testosterone), immune stimulation, impotence, indigestion, inflammation, laryngitis, menstrual pain, migraine headache, muscle or intestinal spasms, ovarian cysts, pain, pelvic congestive syndrome, pelvic inflammatory disease, polycystic ovarian syndrome, postnasal drip, reproductive organ problems, sedation, sexual dysfunction, sore throat, sperm production, testicular atrophy, upper respiratory tract infection, urethritis, urinary antiseptic, urinary tract disorders, uterine disorders, vaginal disorders.

Interactions

Interactions with Drugs

Saw palmetto may increase the risk of bleeding when taken with drugs that increase the risk of bleeding. Some examples include aspirin, anticoagulants (blood thinners) such as warfarin (Coumadin®) or heparin, antiplatelet drugs such as clopidogrel (Plavix®), and nonsteroidal anti-inflammatory drugs such as ibuprofen (Motrin®, Advil®) or naproxen (Naprosyn®, Aleve®). Some batches of the discontinued combination herbal preparation PC-SPES®, which contains saw palmetto and seven other herbs, has been found to contain several medications including the blood thinner warfarin.

Saw palmetto may affect blood pressure. Caution is advised in people taking drugs that may affect blood pressure.

Early research found that saw palmetto lacks effect on cytochrome P450 1A2, 3A4, 2E1, or 2D6 activity.

Saw palmetto may also interact with agents that may affect hemoglobin levels, agents that may affect the immune system, agents that may affect the liver, agents that may lower seizure threshold, agents that may regulate heart rate, agents that may treat genitourinary tract disorders, agents that may treat impotence, agents that may treat stomach disorders, antibiotics, anticancer agents, anti-inflammatories, disulfiram (Antabuse®), and hormonal agents (such as androgens or antiandrogens).

Interactions with Herbs and Dietary Supplements

Saw palmetto may increase the risk of bleeding when taken with herbs and supplements that are believed to increase the risk of bleeding. Multiple cases of bleeding have been reported with the use of Ginkgo biloba, and fewer cases with garlic. Numerous other agents may theoretically increase the risk of bleeding, although this has not been proven in most cases.

Saw palmetto may affect blood pressure. Caution is advised in people taking herbs or supplements that affect blood pressure.

Early research found that saw palmetto lacks effect on cytochrome P450 1A2, 3A4, 2E1, or 2D6 activity.

Tannins in saw palmetto may prevent iron absorption.

Saw palmetto may also interact with antibacterials, anticancer herbs and supplements, anti-inflammatories, cat's claw, echinacea, herbs and supplements that may affect hemoglobin levels, herbs and supplements that may affect the immune system, herbs and supplements that may lower seizure threshold, herbs and supplements that may regulate heart rate, herbs and supplements that may treat genitourinary tract disorders, herbs and supplements that may treat impotence, herbs and supplements that may affect the liver, herbs and supplements that may treat stomach disorders, hormonal herbs and supplements (such as androgens, antiandrogens, or phytoestrogens), Pinus pinaster, and Urtica dioica.

Methodology

This information is based on a systematic review of scientific literature and was peer-reviewed and edited by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

Monograph methodology

Related terms

American dwarf palm tree, American saw palmetto, Arecaceae (family), Bazoton®, Beltrax Uno®, cabbage palm, dwarf palm, dwarf palm plant, Elusan® Prostate, fatty acids, Harzol®, IDS 89, Libeprosta®, LSESR, myristoleic acid, PA 109, Palmae (family), palmetto scrub, palmier de l' Amerique du nord (French), palmier nain (French), PC-SPES®, Permicaps®, Permixon®, Prostadyn®, Prostagood Mono®, Prostamen®, Prostamol Uno®, Prostasan®, Prostaserene®, Prostaserine®, ProstaX®, Remigeron®, sabal, Sabalfruchte (German), Sabal fructus, Sabal serrulata, Sabal serrulata (Michx.) Nutall ex. Schultes & Schultes, Sabal serrulatum, savpalme (Danish), saw palmetto berry, Serendar, Serenoa, Serona repens, Serenoa serrulata, Serenoa serrulata Hook F., Serenoae repentis fructus, SG 291, sterols, Strogen®, Strogen forte®, Tadenan®, Talso®, Urocaps®, Urogutt®, WS 1473, Zwegpalme.

Select combination products: Cernitin®, Cerniton AF™, indigal plus, IPBTRE, PRO 160/120 (Prostagutt® forte), Profluss®, Prostagutt®, Prostataplex™.

Note: Information on pygeum (Prunus africanum, Pygeum africanum) is available in a separate Natural Standard monograph.

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 seven other herbs, reports that three out of 70 people developed allergic reactions. In one case, the reaction included throat swelling and difficulty breathing.

Avoid in people who are allergic or sensitive to saw palmetto, any of its parts, or other members of the Arecaceae or Palmae family.

Side Effects and Warnings

Few severe side effects of saw palmetto are noted in the published scientific literature. A study found that there may be a lack of herb-drug interactions associated with saw palmetto. Overall, there appear to be few safety concerns with short-term use of saw palmetto. Saw palmetto appears to be well tolerated by most people for up to 3-5 years. LSESR, a particular extract of Serenoa repens, may be better tolerated, although this claim has not been confirmed.

The most common complaints involve the stomach and intestines, and include stomach pain, nausea, vomiting, bad breath, constipation, diarrhea, gas, heartburn, and indigestion. Stomach upset caused by saw palmetto may be reduced by taking it with food.

Some reports describe ulcers, liver damage, liver inflammation, and jaundice (yellowing of the skin), but the role of saw palmetto is not clear in these cases. Similarly, reports of headache, dizziness, insomnia, depression, chest pain, abnormal heart rhythm, heart attack, heart disease, heart failure, high or low blood pressure, respiratory tract problems (including breathing difficulties), and muscle pain have been reported but may not be clearly caused by saw palmetto.

Saw palmetto may also cause or induce bloody urine, breast tenderness or enlargement, changes in blood chemistry, eye problems, flu-like symptoms, genital or urinary problems, hot flashes, inflammation of the pancreas, low energy, menstruation, mouth or teeth problems, physical injury, sexual dysfunction (such as ejaculation problems, erectile dysfunction, impotence, or low sex drive), skeletal muscle breakdown, skin reactions, and testicular pain.

Use cautiously 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.

Use cautiously in people who have high blood pressure, or those taking drugs or herbs and supplements that may affect blood pressure.

Use cautiously in people who have liver disorders or those taking drugs for liver disorders.

Use cautiously in patients with hormone-sensitive conditions or in those taking hormonal agents, due to possible hormonal effects of saw palmetto.

Use cautiously in people who have stomach disorders.

Use cautiously in combination with agents that may affect hemoglobin levels. Saw palmetto may reduce levels of hemoglobin, hematocrit, red blood cells, and platelets.

Avoid saw palmetto in women who are or may potentially be pregnant, due to the risk of developmental problems in the baby and hormonal effects.

Avoid saw palmetto when breastfeeding, due to a lack of available information.

Avoid saw palmetto in children, due to a lack of available information.

Avoid in people who are allergic or sensitive to saw palmetto, any of its parts, or other members of the Arecaceae or Palmae family.

In theory, prostate-specific antigen (PSA) levels may be artificially lowered by saw palmetto, based on a proposed mechanism of action of saw palmetto (inhibition of 5-alpha-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 seven other herbs, has been found to contain prescription drugs including warfarin, a blood thinner. The U.S. Food and Drug Administration (FDA) has issued a warning not to use PC-SPES® for this reason, and it is no longer commercially available.

Pregnancy and Breastfeeding

Due to limited safety data, possible hormonal activity, and the risk of developmental problems in the baby, saw palmetto extract is not recommended for women who are or may potentially be pregnant, or women who are breastfeeding. Many tinctures contain high levels of alcohol and should be avoided during pregnancy.

Selected references

  1. Anceschi R, Bisi M, Ghidini N, et al. Serenoa repens (Permixon(R)) reduces intra- and postoperative complications of surgical treatments of benign prostatic hyperplasia. Minerva Urol.Nefrol. 2010;62(3):219-223.
  2. Barry MJ, Meleth S, Lee JY, et al. Effect of increasing doses of saw palmetto extract on lower urinary tract symptoms: a randomized trial. JAMA 9-28-2011;306(12):1344-1351.
  3. Bercovich E and Saccomanni M. Analysis of the results obtained with a new phytotherapeutic association for LUTS versus control. [corrected]. Urologia. 2010;77(3):180-186.
  4. Bertaccini A, Giampaoli M, Cividini R, et al. Observational database serenoa repens (DOSSER): overview, analysis and results. A multicentric SIUrO (Italian Society of Oncological Urology) project. Arch.Ital.Urol.Androl 2012;84(3):117-122.
  5. Giulianelli R, Pecoraro S, Sepe G, et al. Multicentre study on the efficacy and tolerability of an extract of Serenoa repens in patients with chronic benign prostate conditions associated with inflammation. Arch.Ital.Urol.Androl 2012;84(2):94-98.
  6. Kul'chavenia EV, Breusov AA, Brizhatiuk EV, et al. [Approaches to raising efficacy of treatment of patients with chronic prostatitis associated with intracellular infections]. Urologiia. 2010;(6):55-58.
  7. Lapi F, Gallo E, Giocaliere E, et al. Acute liver damage due to Serenoa repens: a case report. Br.J.Clin.Pharmacol. 2010;69(5):558-560.
  8. Lee JY, Foster HE, McVary KT, et al. Recruitment of participants to a clinical trial of botanical therapy for benign prostatic hyperplasia. J.Altern.Complement Med. 2011;17(5):469-472.
  9. MacDonald R, Tacklind JW, Rutks I, et al. Serenoa repens monotherapy for benign prostatic hyperplasia (BPH): an updated Cochrane systematic review. BJU.Int. 2012;109(12):1756-1761.
  10. Mantovani F. Serenoa repens in benign prostatic hypertrophy: analysis of 2 Italian studies. Minerva Urol.Nefrol. 2010;62(4):335-340.
  11. Miroddi M, Carni A, Mannucci C, et al. Hot flashes in a young girl: a wake-up call concerning Serenoa repens use in children. Pediatrics 2012;130(5):e1374-e1376.
  12. Morgia G, Mucciardi G, Gali A, et al. Treatment of chronic prostatitis/chronic pelvic pain syndrome category IIIA with Serenoa repens plus selenium and lycopene (Profluss) versus S. repens alone: an Italian randomized multicenter-controlled study. Urol.Int. 2010;84(4):400-406.
  13. Scaglione F, Lucini V, Pannacci M, et al. Comparison of the potency of 10 different brands of Serenoa repens extracts. Eur.Rev.Med.Pharmacol.Sci. 2012;16(5):569-574.
  14. Villanueva S and Gonzalez J. Coagulopathy induced by saw palmetto: a case report. Bol.Asoc.Med.P.R. 2009;101(3):48-50.
  15. Wargo KA, Allman E, and Ibrahim F. A possible case of saw palmetto-induced pancreatitis. South.Med.J. 2010;103(7):683-685.

This evidence-based monograph was prepared by The Natural Standard Research Collaboration

www.naturalstandard.com