The science is in. Modern research has proven what civilizations have known for thousands of years. From the preservation of Egyptian mummies to Native Americans' natural defense against mosquitoes, cedarwood oil has proven highly effective as nature's own insect repellent. Check out the science behind Cedar Oil. Some of the products in this collection of papers do not carry the Hartman brand name, but they are formulated exactly the same and demonstrate the efficacy of our Cedar Oil products.