What Are The Side Effects Of Saw Palmetto?

Our pharmacist answers the latest question regarding the potential side effects of saw palmetto.

What Are The Side Effects Of Saw Palmetto?
Nov 02, 2017

Bootie asked

What are the side effects of saw palmetto? I want to use it for an enlarged prostate.


Saw Palmetto 1
Saw palmetto (Serenoa repens) is a popular over the counter herbal supplement that is mostly used in men for enlarged prostate or BPH (Benign Prostate Hyperplasia). 

Overall, studies show that short term use (3-5 years) of saw palmetto is generally well tolerated and largely free of adverse effects.  The most commonly reported side effects are as follows:

  • Headache
  • Nausea
  • Vomiting
  • Diarrhea
  • Dyspepsia
  • Loss of libido

Many of the above gastrointestinal side effects may be lessened by taking your saw palmetto product with food.

There have been isolated case reports of more serious side effects, but it is unknown whether or not saw palmetto was a major factor in them happening. Below, we list some of the potentially rare side effects that have been reported.

Saw Palmetto Side Effects


There are rare reports of certain cardiovascular side effects such as hypertension and angina. Here is a link to one of the larger studies that reported these adverse effects: Study. In that study, 3.1% of the test participants using saw palmetto noticed elevated levels of blood pressure vs. 2.2% in those not taking saw palmetto.


There is some concern that saw palmetto may posses mild anti androgenic effects, much like a popular BPH drug Propecia (finasteride). This could be the reason some people experience a loss of libido. Sexual dysfunction (i.e. impotence, premature ejaculation) may also be an adverse reaction due tothe anti-androgenic effects.


The FDA has received very rare case reports of bleeding episodes in those taking saw palmetto. One such case report can be found here: Case Report

Overall however, saw palmetto is one of the most widely used natural products and has a very strong history of safe use. If you have further questions regarding its use or interactions with medications, speak to your doctor or pharmacist.

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