Introduction
According to the American Cancer Society, an estimated 68,720 people in the United States will be diagnosed with skin cancer in 2009. That same year an estimated 8,650 will die from the disease. The largest determining factor in the development of skin cancer is exposure to the ultraviolet rays of the sun, as well as exposure to ultraviolet rays of tanning products, such as tanning beds. Because of the dangers of ultraviolet rays, many people are turning to sunless tanning products to achieve the skin glow of a tan, without the dangers of skin cancer.
Tyrosine
There are two main types of sunless tanning products on the market. One of these products' active ingredient is tyrosine. Tyrosine is a type of amino acid that acts as a tan accelerator. When applied to the skin, it penetrates deep into the skin layers and works as a catalyst on melanocytes. Melanocytes are responsible for producing your skin pigment, called melanin. The increased production of melanocytes, due to exposure to tyrosine, helps darken the overall look of the skin.
Dihydroxyacetone
The most popular ingredient in many sunless tanning products is dihydroxyacetone. Dihydroxyacetone is a naturally occurring sugar that, when exposed to dead skin cells, causes the cells to take on the look of a tan. Dihydroxyacetone's popularity largely comes from being the only ingredient approved by the FDA for sunless tanning products.
Results
Depending on the type of product used, sunless tanning results can vary. Most sunless tanning products only last for about a week before starting to fade. This is due to the skin's natural process of growing new skin cells and shedding older skin cells. New tanner must be applied to color the new skin cell growth. Results can be lengthened by exfoliating your skin before applying the sunless tanner. This allows newer skin cells to be affected, rather than just dead skin cells; however, exfoliating does not increase the results length for tyrosine products, as the tanner only affects dead skin cells.
