As you may know, some medications, including over the counter cold medications, which you can get without a prescription, should not be taken by people with Long QT Syndrome. Heart arrhythmias have been linked with many over-the-counter pills, supplements and herbal remedies.  For a complete list of medications (not dietary supplements or herbal remedies) to be avoided, click here. 

While it may not be that all herbal remedies and dietary supplements are considered harmful to patients with Long QT Syndrome, it is important to talk to your physician before taking any new herbal/dietary supplent.

Here are some resources for determining the safety of dietary supplements:

• National Institutue of Health - Office of Dietary Supplements
• National Institue of Health - National Center for Complimentary and Alternative Medicine

Research related to dietary supplements & arrhythmias:

• A study from 2005 by Dr. Brian McBride, found that 60 percent of the patients who took Metabolife356, a popular weight loss supplement, had their QT prolonged by 30 milliseconds. As a comparison, he pointed out that the FDA either banned or refused to approve several drugs that prolonged QT by just 13 milliseconds-among them the popular allergy drug Seldane. 


Electrocardiographic effects of an Ephedra-Free, multicomponent weight-loss supplement in healthy volunteers.
Min B, McBride BF, Kardas MJ, Ismali A, Sinha V, Kluger J, White CM.
Pharmacotherapy. 2005 May;25(5):654-9.
School of Pharmacy, University of Connecticut, Storrs, 06102, USA.