How an individual’s skin ages depends on a variety of factors: environment, diet, exercise, heredity, and personal habits. Smoking, for example, can produce free radicals–once-healthy oxygen molecules that are now overactive and unstable–which can damage skin cells, leading to premature wrinkles. There are other reasons, too. Primary factors contributing to wrinkled, spotted skin include normal aging, exposure to the sun (photoaging), and loss of subcutaneous support (fatty tissue between your skin and muscle). Other factors that contribute to aging of the skin include stress, gravity, daily facial movement, obesity, and even sleep position. Injections of stem cells and/or stem-cell augmented fat, especially with PRP, has been shown to reverse signs of aging.