Q: What effect does taking saw palmetto have on Coumadin levels??

Q: Dr. Gourmet Says...

It's important to check with your doctor about taking any supplements if you are on any prescription medication including Coumadin® (warfarin) but also others such as blood pressure medications and medications for cholesterol or diabetes.

The research on taking supplements is disappointing and few have shown any benefit.  This includes saw palmetto which in a large trial was shown to have no positive effects.  

This is from the National Institute of Health web site:

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, anti-platelet drugs such as clopidogrel (Plavix®), and non-steroidal 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.

It's best to avoid supplements while on prescription medication unless you have a discussion with your physician first.  

Thanks for writing,

Dr. Gourmet
Eat well, eat healthy, enjoy life!