Your skin is your largest organ and the most exposed. It has many built-in protections and one of them is developing a tan. When UV rays hit the skin they penetrate the to lower level of the epidermis. UV rays are very powerful and very dangerous to the skin. That’s why the skin starts to burn after too much exposure to UV rays, whether from the sun or a tanning bed. Your body is trying to cool the skin with capillary action. Once the capillaries begin to break down your start getting red and that’s a sunburn. Very dangerous for your skin as it causes cellular breakdown and allows free radicals to attack the cells. This can cause mutations in DNA and lead to skin cancer down the road.
There is no safe way to tan. Any exposure to ultraviolet light increases the risk of skin cancer. There are self-tanning lotions or sunless tanning salons that use spray tanning, actually an inaccurate term because it is just a deposition of pigment onto the skin without any exposure to UV light.
If you use a loofah lightly over the body where the self tanning lotion or spray is to be applied, the pigment will go on more evenly.
And even though you don’t wish to be convinced not to tan for health reasons, I am going to take a chance and ask you to consider the risks you as a young person are incurring by tanning in the sun. Please consider using a broad spectrum sunscreen and sun protective clothing when out in the sun to minimize the risk of skin cancer.
So back to your real question, When UV A rays penetrate to the lower epidermis, melanocyte stimulating hormones (MSH) are emitted and this causes the melanocytes to produce melanin. Melanin is the pigment that cause the skin to darken. Depending upon skin type, some people are able to produce more melanin than others. So with moderate exposure to the sun over a period of time one can develop a tan. Some people think that you have to burn in order to get a tan. THIS IS A COMPLETE AND DANGEROUS FALSEHOOD!! Sunburns are very dangerous as they damage the top layers of the skin that later die and peel away leaving very delicate, damaged skin.
More than 90% of all non-melanoma skin cancer (NMSC) is associated with sun exposure, particularly ultraviolet (UV) radiation.
A previous American Academy of Dermatology campaign poster on sun avoidance and sun protection.
It illustrates the point very well. Our skin constantly accumulates sun damage, which does not disappear.
The development of cancer is a multi-step process. Some agents, like chemicals, radiation, ultraviolet light, etc, start the process by changing the DNA (genetic code) of the cell. There are other substances, called promoters, that take that changed cell and push it to multiply and become a cancer.
Ultraviolet light is one of a few entities that can act both as initiator and promoter, meaning it changes the cell AND pushes it to multiply to become a cancer.
Every time we are exposed to the sun, ultraviolet light damages some cells. Our cells have repair mechanisms, that allow them to cut out the damaged parts and return the cell to normal. If those repair mechanisms do not work, the cells of the immune system that scan the skin on a regular basis, identify changed/precancerous cells and remove them. Ultraviolet light inactivates those cells of the immune system. We use that fact to treat diseases of the skin that involve immune system cells that cause disease in the skin, like psoriasis or a type of skin lymphoma, called mycosis fungoides.
This is true for ultraviolet light exposure from any source, the sun or indoor tanning equipment, that is advertised as “safe tanning.” It is not. Great Britain recently passed a law prohibiting the use of indoor tanning equipment by anyone under the age of 18. In the US, many states are working on similar legislation.
So, just to repeat there is no safe way to tan with any source of ultraviolet light, either sun exposure or indoor tanning equipment.