Sunless tanning
Sunless tanning involves the use of oral agents (carotenids), or creams, lotions or sprays applied to the skin.
A safe and effective method of sunless tanning is consumption of certain carotenoids[5][6][7]—antioxidants found in some fruits and vegetables such as carrots and tomatoes—which can result in changes to skin color when ingested chronically and/or in high amounts.
"[17] Chronic, high doses of synthetic β-carotene supplements have been associated with increased rate of lung cancer among those who smoke.
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.
[22][23] DHA (dihydroxyacetone, also known as glycerone) is not a dye, stain or paint, but causes a chemical reaction with the amino acids in the dead layer on the skin surface.
It does not involve the underlying skin pigmentation nor does it require exposure to ultraviolet light to initiate the color change.
However, for the 24 hours after self-tanner is applied, the skin is especially susceptible to ultraviolet, according to a 2007 study led by Katinka Jung of the Gematria Test Lab in Berlin.
For a day after self-tanner application, excessive sun exposure should be avoided and sunscreen should be worn outdoors, they say; an antioxidant cream could also minimize free radical production.
Although some self-tanners contain sunscreen, its effect will not last long after application, and a fake tan itself will not protect the skin from UV exposure.
The study by Jung et al. further confirms earlier results demonstrating that dihydroxyacetone in combination with dimethylisosorbide enhances the process of (sun-based) tanning.
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.
[33] An opinion[34] issued by the European Commission's Scientific Committee on Consumer Safety, concluding spray tanning with DHA did not pose risk, has been heavily criticized by specialists.
Thus, nearly every report the commission's eventual opinion referenced came from studies that were never published or peer-reviewed and, in the majority of cases, were performed by companies or industry groups linked to the manufacturing of DHA.
The industry left out nearly all of the peer-reviewed studies published in publicly available scientific journals that identified DHA as a potential mutagen.
A study by scientists from the Department of Dermatology, Bispebjerg Hospital, published in Mutation Research has concluded DHA 'induces DNA damage, cell-cycle block and apoptosis' in cultured cells.
[41][42][43] Afamelanotide is also being investigated as a method of photoprotection from in the treatment of polymorphous light eruption, actinic keratosis and squamous cell carcinoma (a form of skin cancer).
[48] A number of products are sold online and in gyms and beauty salons as "melanotan" or "melanotan-1" which discuss afamelanotide in their marketing.
[56][57][58][59][60][61] Eicosanoids, retinoids, oestrogens, melanocyte-stimulating hormone, endothelins, psoralens, hydantoin, forskolin, cholera toxin, isobutylmethylxanthine, diacylglycerol analogues, and UV irradiation all trigger melanogenesis and, in turn, pigmentation.
[63] If bronzer is applied under clothing, or where fabric and skin edges meet, most will create some light but visible rub-off.
It's important to continue wearing SPF while self-tanning, as self-tanner is generally a fake and temporary tan, and your skin is still sensitive to the sun.
[70] If avobenzone-containing sunscreen is applied on top of tanner, the photosensitizer effect magnifies the free-radical damage promoted by DHA, as DHA may make the skin especially susceptible to free-radical damage from sunlight, according to a 2007 study led by Katinka Jung of the Gematria Test Lab in Berlin.
"[71] A study by scientists from the Department of Dermatology, Bispebjerg Hospital, published in Mutation Research has concluded DHA 'induces DNA damage, cell-cycle block and apoptosis' in cultured cells.
