Q: Is Polygonum multiflorum (Chinese: He shou wu, also known as Fo-ti) a blood thinner?

A: In Chinese medicine Polygonum multiflorum is listed in the Herb category "Herbs that Tonify the Blood". It tonifies the Liver and Kidneys, nourishes blood, and augments the essence (Jing). It is commonly used because it both tonifies and preserves and is found in many formulas.

Clinical research shows that it reduces cholesterol. In one study of 88 people with high cholesterol, 78 had a decrease in cholesterol levels.

While I have not reviewed all the literature I do not believe it acts as a blood thinner. Chinese medicine has another category of herbs, titled "Herbs that Circulate Blood". Herbs in this category would be more likely to have blood thinning properties.