In a systematic review by Izzo AA, et al Ginkgo (Ginkgo biloba) was noted to interact with aspirin (acetylsalicylic acid) to increase risk of bleeding. (13)
Policosanol reduced fibrinogen significantly and should not be taken 2 weeks prior to surgery, anyone with a bleeding disorder or fibrinogen deficiency, anyone with a history of major bleeding in the past, anyone taking aspirin, NSAIDs, warfarin, or any type of heparin. Monitoring by a physician should be done with a coagulation profile and fibrinogen every month until stable. If no monitoring occurs policosanol may not be safe. Fibrinogen under 150 is associated with an increased risk of bleeding. (14)