REVIAN uses multiple LED wavelengths that were found during pre-clinical research and a clinical trial to produce significant results over single wavelength laser devices. It is possible that REVIAN may make a positive change for you by potentially slowing hair loss and re-growing and strengthening your hair. No system is 100% guaranteed to grow hair. There are many potential causes of hair loss. They can be as diverse as the people who experience it. Some of the causes of hair loss are prescription drugs or medications, chemicals, heredity, hormones, the environment, inflammation and age. This is why REVIAN includes a money-back guarantee. If you do not see positive hair growth in 6 months and are at least 80% compliant with the treatments you may request a return and refund.