Saw Palmetto Side Effects and Warnings

Safety Issues

Saw palmetto is thought to be essentially nontoxic. ¹ In addition, in clinical trials, it has shown little to no adverse effects. For example, in a one-year randomized trial of 225 men, there was no significant difference in adverse events between the groups receiving saw palmetto and placebo. ² And, in a 3-year study, only 34 of the 435 participants complained of side effects, and these were primarily only of the usual nonspecific variety seen with all medications, such as mild gastrointestinal distress. ³ There are at least two case reports in which use of saw palmetto was linked to liver inflammation; ⁴ however, a subsequent study in rats failed to find that even very high doses of saw palmetto are injurious to the liver. This case report might have been an instance of an allergic or other idiosyncratic reactions; alternatively, something other than saw palmetto may have gotten into the product. One of the above-mentioned cases also involved pancreatitis. ⁵ Finally, there is one report of saw palmetto apparently causing excessive bleeding during surgery. ⁶ The significance of this isolated event isn't clear, but it is probably prudent to avoid saw palmetto prior to and just after surgery, and during the period surrounding labor and delivery. Individuals with bleeding problems (such as hemophilia) should perhaps also avoid saw palmetto, as should those taking any drug that "thins" the blood, such as warfarin (Coumadin), heparin, aspirin , clopidogrel (Plavix) , ticlopidine (Ticlid) , and pentoxifylline (Trental) .

Saw palmetto has no known drug interactions. Safety for pregnant or nursing women, or those with severe kidney or liver disease, has not been established.