Quick Navigation

Saw Palmetto

Saw Palmetto is a fatty acid mix from Serenoa repens that has been touted for its abilities to increase testosterone (not effective) and suppress prostate growth (questionable effectiveness); safe for use in benign prostatic hyperplasia and abnormal urine flow rates in men, but studies have had mixed results in terms of efficacy.

Our evidence-based analysis on saw palmetto features 64 unique references to scientific papers.

Kamal Patel
Research analysis led by .
Reviewed by
Examine.com Team
Last Updated:
NEW: Examine Personalized makes it easy to stay on top of the latest research

Summary of Saw Palmetto

Primary information, health benefits, side effects, usage, and other important details

Saw Palmetto is a supplement which is derived from the fruit of the plant Serenoa repens. The supplement (saw palmetto) has a caloric value, as it is a concoction of fatty acids.

The fatty acids in question have the ability to block an enzyme that converts testosterone into dihydrotestosterone (DHT), the latter of which is a more androgenic form and can cause hairloss in the genetically susceptible.

Its effects on DHT production have also led to saw palmetto being used for benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS) in men. Some studies have shown positive results, but larger and more well-designed studies have brought its efficacy into question.

Make sure you only take supplements that work

Examine.com bases all of its recommendations on published scientific research. We’re a trusted resource because we don’t sell or even advertise supplements.

If you’re tired of wasting time and money on supplements that don’t work, our 17 Supplement Guides will help you figure out precisely what to take — and what to skip — based on your health goals and the latest scientific evidence. There’s a reason why over 50,000 customers rely on Examine.com’s independent and unbiased analysis.

Includes free lifetime updates so you always have the most accurate information.


I want unbiased recommendations to improve my health »

How to Take

Medical Disclaimer

Recommended dosage, active amounts, other details

While the active compound(s) are not yet known, it is known that they exist in what is known as the 'liposterolic' fraction of the fruits. If using saw palmetto choose a product that discloses the percentage of the supplement which is this fraction.

Supplementation of saw palmetto tends to be in the range of 160-320 mg, taken once daily, of a product which is 80-90% liposterolic compounds by weight. While it is not confirmed if saw palmetto needs to be taken with food due to the fat soluble nature of this fraction it is advised.

Get the latest information on 400+ supplements and their effects on 600+ health conditions & outcomes.

By becoming an Examine Plus member, you'll have access to all of the latest nutrition research. Quickly and easily look up scientific research on over 400 supplements across over 600 different health goals, outcomes, conditions, and more.

Already a subscriber to any of our membership plans? Click here to login.

Human Effect Matrix

Unlocked for Examine Plus members

The Human Effect Matrix summarizes human studies to tell you what effects Saw Palmetto has on your body, how much evidence there is, and how strong these effects are.

Full details are available to Examine Plus members.
Grade Level of Evidence
Robust research conducted with repeated double-blind clinical trials
Multiple studies where at least two are double-blind and placebo controlled
Single double-blind study or multiple cohort studies
Uncontrolled or observational studies only
Level of Evidence
? The amount of high quality evidence. The more evidence, the more we can trust the results.
Outcome Magnitude of effect
? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.
Consistency of research results
? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.
Notes
grade-b
Symptoms of Benign Prostatic Hyperplasia
Minor - See all 7 studies
Smaller, shorter trials have noted some effect, but larger, longer trials have noted no effect. The most recent Cochrane meta-analysis also notes no effect.
grade-c
DHT
- - See study
grade-c
Prostate Specific Antigen
Low See all 4 studies
While observational data suggests a decrease, trials have found no change in PSA levels.
grade-c
Testosterone
- Very High See 2 studies
grade-d
Quality of Life
Notable Moderate See 2 studies
grade-d
Hair Regrowth
Minor - See study
Saw palmetto usage over two years (320mg) appears to increase hair growth on the crown in 38% of users with male pattern baldness, a response rate that was less than 1mg finasteride (benefiting 66% of users and also improving hair growth in the frontal region).
grade-d
Sexual Function
Minor Low See all 4 studies
While observational and smaller interventional studies have found some effect, larger and longer trials have not.

Studies Excluded from Consideration

Become an Examine Plus member to access the latest nutrition research on over 400 supplements across over 600 different health goals, outcomes, conditions, and more.

Becoming an Examine Plus member not only unlocks the Human Effect Matrix for supplements, but also all health topics on Examine.com. We neatly summarize all the latest research so you can make the best decisions for your health based on what's accurate and not out-dated information.

Things to Note

Is a Form Of

Primary Function:

Also Known As

Serenoa Repens

Tired of misinformation? Get unbiased info on supplements.

At Examine.com, our incentives line up with yours — getting unbiased information. It’s why we don’t sell any advertising or supplements.

Join over 250,000 people who’ve learned about effective versus overrated supplements, supplement buying tips, and how to combine supplements for safety and efficacy.

Research Breakdown on Saw Palmetto

1Sources and Composition

1.1Origin and Composition

1.2Formulations and Variants

2Molecular Targets

2.1Adrenergic Receptors

2.2Cholinergic Receptors

2.3Ion Channels

2.45α-reductase

3Pharmacology

3.1Phase I Metabolism

4Cardiovascular Health

4.1Cardiac Tissue

5Inflammation and Immunology

5.1Mechanisms

6Interactions with Hormones

6.1Androgens

7Peripheral Organ Systems

7.1Urinary Tract

7.2Prostate

8Interactions with Cancer Metabolism

8.1Glioma

8.2Prostate

9Interactions with Aesthetics

9.1Hair

10Interactions with Medical Conditions

10.1Benign prostatic hyperplasia (BPH)

11Safety and Toxicology

11.1General

11.2Case studies
Click here to see all 64 references.

This page is regularly updated, to include the most recently available clinical trial evidence.

Each member of our research team is required to have no conflicts of interest, including with supplement manufacturers, food companies, and industry funders. The team includes nutrition researchers, registered dietitians, physicians, and pharmacists. We have a strict editorial process.

This page features 64 references. All factual claims are followed by specifically-applicable references. Click here to see the full set of research information and references for Saw Palmetto.

Examine.com is intended to be used for educational and information purposes only. Examine.com and its Editors do not advocate nutritional supplementation over proper medical advice or treatment and this sentiment will never be expressed through pages hosted under Examine.com. If using any pharmaceuticals or drugs given to you by a doctor or received with a prescription, you must consult with the doctor in question or an equally qualified Health Care Professional prior to using any nutritional supplementation. If undergoing medical therapies, then consult with your respective Therapist or Health Care Professional about possible interactions between your Treatment, any Pharmaceuticals or Drugs being given, and possible nutritional supplements or practices hosted on Examine.com.

Examine.com does not assume liability for any actions undertaken after visiting these pages, and does not assume liability if one misuses supplements. Examine.com and its Editors do not ensure that unforeseen side effects will not occur even at the proper dosages, and thereby does not assume liability for any side effects from supplements or practices hosted under the domain of Examine.com.

Supplements

Articles

Health Topics

NERD

Personalized

About

Never miss an update!

Your e-mail is safe with us. We don’t share personal data.

This website is certified by Health On the Net Foundation. Click to verify.