Ginkgo biloba may interact with blood-thinning compounds such as heparin, aspirin, or warfarin, known by the brand name, Coumadin. Ginkgo biloba may intensify anti-clotting effects of drugs because it, too, has anti-clotting properties. Individuals taking these types of drugs may want to avoid using ginkgo biloba. Anyone with an upcoming surgical procedure should consider discontinuing ginkgo biloba well before the surgery. Garlic, ginseng, dong quai, and ginger also may interact with anti-clotting drugs.