Fisetin Side Effects and Precautions

Keep in mind that the safety profile of fisetin is relatively unknown, given the lack of well-designed clinical studies. The list of side effects below is not a definite one, and you should consult your doctor about other potential side effects, based on your health condition and possible drug or supplement interactions.

Even at high doses, scientists found no evidence of side effects or toxicity in animal studies. Clinical studies, of course, are needed to confirm its safety.

In the lone clinical trial on cancer patients, stomach discomfort was reported in the fisetin group. However, this might not actually be a side effect of fisetin. All patients were receiving chemotherapy and the same stomach complaint was also reported in the placebo group.

Due to the lack of safety data, pregnant women and children should avoid fisetin supplements.

Drug Interactions

Supplement-drug interactions can be dangerous and, in rare cases, even life-threatening. Always consult your doctor before supplementing and let them know about all drugs and supplements you are using or considering.

The liver uses the same pathway to process fisetin as it does for the blood-thinning agent warfarin (Coumadin). This can, in theory, increase the effects of warfarin.

Fisetin substantially reduces blood sugar in diabetic animals. The combination with blood sugar-lowering drugs may further reduce sugar levels.