Many people take supplements and botanicals during cancer treatment. The potential for side effects from concurrent use requires physicians to be aware of the risks and benefits that may arise. Some direct evidence for such interaction is defined in the literature, but much of the concern regarding botanical and supplement interactions with chemotherapy and radiation is theoretical. Interactions with chemotherapy drugs affect solubility, absorption, distribution, metabolism, and excretion.

Note: Dietary supplements are intended to supplement the diet. They are not medicines and are not intended to treat, diagnose, mitigate, prevent, or cure disease. In some cases, dietary supplements may have unwanted effects, especially if taken before surgery or with other dietary supplements or medicines, or if you have certain health conditions. Also, supplements are not regulated with the same degree of oversight as medications. Products vary greatly in terms of accuracy of labels, presence of contaminants, and the validity of claims on the label. Work with your health care provider to determine how best to achieve optimal health.

Bleeding Risk

Many supplements and botanicals can increase bleeding and bruising in patients. A blood thinning effect may be desired when they are used to prevent blood clots, venous thromboses, and improve circulation. The mechanisms of action include direct platelet function inhibition or interactions with drugs that are blood thinners. When used by a patient with bleeding tendencies, especially one who has anemia or thrombocytopenia, or is on blood thinner medications (aspirin, nonsteroidal anti-inflammatory drugs [NSAIDs], platelet inhibitors, warfarin, new oral anticoagulants [NOACs]), it can lead to unwanted bleeding and bruising. Patients who are on these should discontinue their use 10 days before surgery to reduce the chance of perioperative bleeding and hemorrhage.

Supplements and Botanicals that May Increase Bleeding Risk¹