Tattoo removal/reduction employs a Q-switched Nd YAG laser at 2 different wavelengths: 532nm and 1064nm. This type of laser is called Q-Switched. The q-switching is important, as this is a photo (light) acoustic (shock wave) type of laser. The light energy is emitted in short bursts. These very brief bursts of light create a shock wave that breaks up the very large ink particles (which cannot be absorbed by the body) into much smaller particles. With each session, some parts of the larger ink particles get broken into smaller ones. The small ones are absorbed by the white blood cells and removed from the body. Over a series of sessions, the tattoo is reduced and often eliminated.
Some colours are easier than others to breakdown and remove: black, brown, navy blue, and red are the easiest. Any colours mixed with white (pastels) are very difficult as are yellow inks and green inks. Black can often be the easiest, but in uncommon situations it is highly refractory to treatment. The white, yellow, green and some black ink can be impossible to remove. Permanent make up pigments are often fraught with difficulties – if they are mixed with iron oxides, then they can turn black. In general permanent makeup tattoos are best left alone.
Although excellent results are expected in most, like all areas of medicine, each person responds differently and no guarantees can be given.