The active ingredient in the sunless solution, Dihydroxyacetone or DHA, works with the skin's proteins and amino acids and turns the skin a brown color when it's exposed to oxygen. To draw a comparison, it’s a process similar to what happens when you slice open an apple and leave it sitting out. The flesh turns brown due to it’s exposure to air also known as oxidation.
Most tattoos contain enough pigment that the DHA will only affect the skin, and not the color of the tattoo. Some lighter colors such as pale yellows, flesh colors, or white tattoos may, however, darken slightly with the application of DHA. The majority of our "tatted up" clients have found no issue with spray tanning over their tattoos and spray tan weekly.
If you are concerned about your tattoo, ask your spray tan technician to apply a bit of barrier cream to the area prior to spraying to protect to color. When exposed to UV light from the sun or a tanning bed, proper precautions should be taken to keep the color from fading. Try using a broad spectrum SPF sunblock or tattoo balm stick to protect your tattoo.
Read more spray tan tips from STOP and GLOW