Coenzyme Q10

Also known as: ubiquinone, ubiquinol, CoQ

Potential uses: Coenzyme possibly reduces the risk of some cancers, boosts the immune system, and possibly protects the heart from the side effects of some chemotherapy. It acts as an antioxidant.

Usual dose: 180 milligrams per day. When the dose is higher than 100 milligrams per day, it's recommended that you take some in the morning and some in the evening, or even split it into three smaller doses with each meal.

Are there any risks? While no significant side effects have been reported by women taking coenzyme Q10, some women do have nausea, diarrhea, insomnia, and a reduced appetite.

What does the research show? In animals, coenzyme Q10 has been shown to stimulate the immune system. But this finding has not been repeated with people. Only one randomized clinical trial has been done with cancer patients so far. This trial suggested that coenzyme Q10 decreases the effects of doxorubicin, a chemotherapy drug, on the heart. In non-randomized studies with women who had breast cancer, some benefit was suggested, but problems with the research made it impossible to determine whether the benefit was related to coenzyme Q10.