The examples and perspective in this article deal primarily with the United States and do not represent a worldwide view of the subject. Please improve this article and discuss the issue on the talk page. (August 2010)

Sunless tanning (also known as UV-free tanning, self tanning, spray tanning (when applied topical, or fake tanning) refers to the application of chemicals to the skin to produce an effect similar in appearance to a suntan. The popularity of sunless tanning has risen since the 1960s after links were made by health authorities between exposure to the sun, and other sun tanning methods, such as sunbeds or tanning beds, and the incidence of skin cancer.

Natural sunscreen[link]

Artificial sunscreen absorbs ultraviolet light and prevents it from reaching the skin. It has been reported that sunscreen with a sun protection factor (SPF) of 8 based on the UVB spectrum can decrease vitamin D synthetic capacity by 95 percent, whereas sunscreen with an SPF of 15 can reduce synthetic capacity by 98 percent (Matsuoka et al., 1987).^[1]

The safest and most effective sunless tanning is some carotenoids that can be taken in chronic high doses needed for permanent change in skin pigment. Carotenoids are natural, permanent, improves tanning, and even act as permanent defense against UV light-mediated skin damage unlike most sunless tanning products. Also, carotenoids have been linked to more attractive skin tone than suntan.^[2] Carotenoids occur naturally in fruit and vegetables, giving them their strong colours.

Carotenaemia (xanthaemia) is the presence in blood of the yellow pigment carotene from excessive intake of carrots or other vegetables containing the pigment resulting in increased serum carotenoids. It can lead to subsequent yellow-orange discoloration (xanthoderma or carotenoderma) and their subsequent deposition in the outermost layer of skin. Carotenemia and carotenoderma is in itself harmless, and does not require treatment. In primary carotenoderma, when the use of high quantities of carotene is discontinued the skin color will return to normal. It may take up to several months, however, for this to happen.

Carotenoids safe in chronic high doses[link]

Lycopene[link]

Lycopene is a key intermediate in the biosynthesis of beta-carotene, and xanthophylls. While chronic, high doses of β-carotene supplements have been associated with increased rate of lung cancer among those who smoke evidence for lycopene’s benefit was strongest for cancers of the lung, stomach, and prostate gland. Lycopene is found in lung tissue and is valuable in protecting lymphocytes from NO2 damage found in lung cancer.

Lycopene may be the most powerful carotenoid quencher of singlet oxygen,^[3]

Due to its strong color and non-toxicity, lycopene is a useful food coloring (registered as E160d) and is approved for usage in the USA^[4], Australia and New Zealand (registered as 160d)^[5] and the EU^[6].

Carotenoids not safe in chronic high doses[link]

Beta-carotene[link]

A sunless-tanning product is tanning pills which contain beta-carotene.

However, chronic, high doses of synthetic β-carotene supplements have been associated with increased rate of lung cancer among those who smoke. This may be prevented by combine β-carotene with lycopene that is found in lung tissue and is valuable in protecting lymphocytes from NO2 damage found in lung cancer.

Canthaxanthin[link]

Canthaxanthin is most commonly used as a color additive in certain foods. Although the FDA has approved the use of canthaxanthin in food, it does not approve its use as a tanning agent. When used as a color additive, only very small amounts of canthaxanthin are necessary. As a tanning agent, however, much larger quantities are used. After canthaxanthin is consumed, it is deposited throughout the body, including in the layer of fat below the skin, which turns an orange-brown color. These types of tanning pills have been linked to various side effects, including hepatitis and canthaxanthin retinopathy, a condition in which yellow deposits form in the retina of the eye. Other side effects including damage to the digestive system and skin surface have also been noted. The FDA withdrew approval for use of canthaxanthin as a tanning agent, and has issued warnings concerning its use.^[7]

Other products[link]

DHA-based products[link]

The most effective sunless tanning involves the use of lotions and sprays that contain dihydroxyacetone (DHA) as the active ingredient. DHA is not a dye, stain or paint, but causes a chemical reaction with the amino acids in the dead layer on the skin surface.^[8] This is similar to the Maillard reaction, a process well known to food chemists that causes the browning that occurs during food manufacturing and storage. It does not involve skin pigmentation nor does it require exposure to ultraviolet light to initiate the color change. The effect is temporary and fades gradually over 3 to 10 days.

These products are available as gels, lotions, mousses, sprays and wipes, some of which also use erythrulose which works identically to DHA, but develops more slowly. Both DHA and erythrulose have been known to cause contact dermatitis.

Professional spraytan applications are available from spas, salons and gymnasiums by both hand-held sprayers and in the form of sunless or UV-Free spray booths.^[9] The enclosed booth, which resembles an enclosed shower stall, sprays the tanning solution over the entire body. The U.S. Food and Drug Administration (FDA) states when using DHA-containing products as an all-over spray or mist in a commercial spray "tanning" booth, it may be difficult to avoid exposure in a manner for which DHA is not approved, including the area of the eyes, lips, or mucous membrane, or even internally. DHA is not approved by the FDA for inhalation.^[9]

DHA has been approved for cosmetic use by the FDA.^[10] Because DHA does not use the skin's melanocytes to make the skin a tan color, it is recommended as a cosmetic disguising cover for vitiligo patients.

Tyrosine-based products[link]

Although gels, lotions or sprays that contain DHA are said to be the most reliable and useful, there are other types of products on the market. Tanning accelerators—lotions or pills^[7] that usually contain the amino acid tyrosine -- claim that they stimulate and increase melanin formation, thereby accelerating the tanning process. These are used in conjunction with UV exposure. At this time, there is no scientific data available to support these claims.

Melanotan hormone[link]

Afamelanotide, a synthetic melanocyte-stimulating hormone analog, which induces melanogenesis through activation of the melanocortin 1 receptor, is another alternative on the horizon. A 1991 clinical Investigational new drug trial conducted at the Department of Internal Medicine, University of Arizona Health Sciences Center with afamelanotide (then known by its amino acid formula [Nle⁴, D-Phe⁷] (NDP)-alpha-melanocyte-stimulating hormone) with 28, "healthy white men" who used a, "high-potency sunscreen during the trial" and concluded, "Human skin darkens as a response to a synthetic melanotropin given by subcutaneous injection. Skin tanning appears possible without potentially harmful exposure to ultraviolet radiation." ^[11]

Afamelanotide in a subcutaneous implant form is currently undergoing clinical trials and being developed by a company in Australia.

Temporary bronzers[link]

Bronzers are a temporary sunless tanning or bronzing option. These come in powders, sprays, mousse, gels, lotions and moisturizers. Once applied, they create a tan that can easily be removed with soap and water. Like make-up, these products tint or stain a person's skin only until they are washed off.

They are often used for "one-day" only tans, or to complement a DHA-based sunless tan. Many formulations are available, and some have limited sweat or light water resistance. If applied under clothing, or where fabric and skin edges meet, most will create some light but visible rub-off. Dark clothing prevents the rub-off from being noticeable. While these products are much safer than tanning beds, the color produced can sometimes look orangey and splotchy if applied incorrectly.

A recent trend is that of lotions or moisturizers containing a gradual tanning agent. A slight increase in color is usually observable after the first use, but color will continue to darken the more the product is used.

Air brush tanning is a spray on tan performed by a professional. An air brush tan can last five to ten days will fade when the skin is washed. It is used for special occasions or to get a quick dark tan. At-home airbrush tanning kits and aerosol mists are also available.

Risks[link]

Most sunless tanning products do not contain sunscreen, therefore, they do not provide any protection against ultraviolet rays when the person is outdoors. To offer protection against UV rays the tanner should contain an SPF. The ingredients known to offer appropriate protection are titanium dioxide, zinc oxide, or avobenzone.^[12]

Risks of inhaling or ingesting DHA are not known. People are advised to close their eyes or protect them with goggles and to hold their breath or wear nose plugs while they have a spray-on tanning applied.^[13]

Many self tanners use chemical fragrances which may cause skin allergies or may trigger asthma. Furthermore, some of them contain parabens. Parabens are preservatives that can affect the endocrine system.^[14]

Tanners can stain clothes. It is therefore important to look for fast drying formulas and wait around 10 to 15 minutes for the product to dry before dressing.

For the 24 hours after self-tanner (containing high DHA levels, ~5%) is applied, the skin is especially susceptible to free-radical damage from sunlight, according to a 2007 study led by Katinka Jung of the Gematria Test Lab in Berlin.^[15] Forty minutes after the researchers treated skin samples with high levels of DHA they found that more than 180 percent additional free radicals formed during sun exposure compared with untreated skin.

See also[link]

• Beta-carotene
• Sun tanning
• Sunburn

References[link]

External links[link]

• FDA listing of approved colorants
• American Academy of Dermatology on Self Tanners