A Standford medical study said
"According to science, red light isn't bogus. With a process called selective photothermolysis, light can be tailored to use specific wavelengths to target tissue and stimulate an effect within tissue. The shorter the wavelength of light, the more potent it is, making it a tunable tool — shorter wavelengths can be used to kill skin cells, while longer ones can help heal or stimulate cell growth or the production of different molecules, such as collagen-building proteins."
Another study by the National Library of Medicine concluded
"This clinical study confirms the interest of photobiomodulation in the treatment of the signs of skin aging. From the very first sessions, whatever the age of the person, the visible effects of reversing the signs of aging are not only observable but also measurable."