Humans have used herbs for thousands of years as medicines and tonics to improve general health. Many herbs seem to have properties that improve blood circulation by thinning your blood and increasing the amount of time that it takes for your blood to clot. In most cases, however, health claims about herbs that improve blood circulation haven't been proven in rigorous medical testing. Some herbs may even interfere with prescription medications. If you're considering taking an herb to increase blood circulation, talk to your doctor first to make sure it's right for you.
The herb ginkgo biloba comes from one of the oldest living species of trees on Earth. Ginkgo biloba supplements rank among the top-selling herbal remedies in both the United States and Europe. One component of the herb appears to improve blood circulation by dilating your blood vessels and making your platelets less "sticky," according to the University of Maryland Medical Center. It may help improve symptoms of Alzheimer's disease by improving blood flow directly to your brain, although research isn't clear on this point. Although the University of Maryland Medical Center notes that ginkgo biloba appears to be safe, always talk with your doctor before taking any herb, including ginkgo biloba.
Willow bark contains salicin, a chemical similar to aspirin, and humans have used it to treat inflammation and pain since around 400 B.C., according to the University of Maryland Medical Center. Willow bark appears to work in a similar fashion as aspirin to thin your blood and promote improved blood circulation, although fewer studies have been conducted on willow bark than on ginkgo biloba. Like aspirin, willow bark can contribute to stomach ulcers and stomach bleeding, and it can interact with prescription medications, so check with your doctor before taking it. An overdose of willow bark can cause nausea, vomiting, skin rash, kidney problems and ringing in your ears.
Natural health practitioners often recommend bilberry as a treatment for diarrhea, according to McKinley Health Center at the University of Illinois at Urbana-Champaign, but it can also improve blood circulation by helping to thin the blood. Very few studies show bilberry's effects on humans, according to the University of Maryland Medical Center. In Europe, bilberry is used to improve circulation in cases of chronic venous insufficiency, which occurs when veins in your legs become damaged and no longer carry enough blood to the heart. Animal testing provides evidence that bilberry may improve circulation in atherosclerosis patients; however, no studies have been done in humans to back this use. Bilberry appears safe, but like other herbs that may increase your blood circulation, check with your doctor before using it.