Get details on how laser tattoo removal works

See what’s happening and what factors determine the number of sessions.

Tattoo inks consist of many different compounds which is one of the many reasons why determining the number of sessions required to remove them can be difficult.

Like paint, crayons, markers etc. tattoo inks come in many different varieties. The older a tattoo the easier it is to remove because the tattoo ink from many years ago is not as resilient as it is today.

From the moment a needle deposits ink deep in the skin, the immune system recognizes the these particles as foreign intruders, dispatching armies of white blood cells to engulf them. The white blood cells then escort small ink particles to the liver, where they are processed and excreted.

Generally, many of the ink particles are much larger than white blood cells, which is why new tattoos fade over time, but won’t completely disappear naturally.

You can see the size difference in the animated image below. The black splotches are ink particles, which dwarf the blood cells swimming around them.

Microscope image of tattoo ink and white blood cells

Over time, the white blood cells eat away at the ink particles, but most are still too large for the white blood cells to grab onto and remove from the skin. This is the reason tattoos are permanent. To erase a tattoo, you need lasers to break up the ink particles.

Does Tattoo Removal Work?

Tattoo removal lasers, also called Q-switch lasers or ultra-short pulse lasers, are extremely hot, operate in a very narrow frequency, and are very, very fast. This speed and heat is crucial to cracking the ink particles apart. To break up an ink particle, you need to heat it to make it expand due to thermal expansion, but the zap has to be quick enough so that half of the particle remains cool. The opposing cool and hot forces then separate the ink particles into smaller pieces.

Once the lasers break the ink particles apart into bite-sized chunks, the white blood cells can absorb them for transportation to the liver.

Animation of how laser tattoo removal works to break up tattoo ink

Now, this may sound relatively easy, but the process is very unique to each person. The number of sessions varies substantially from tattoo to tattoo and person to person.

How Does Tattoo Removal Feel?

Having a tattoo removed can be quite painful, often more so than getting a tattoo in the first place. The lasers heat the ink particles to thousands of degrees, but it happens so rapidly and specifically directed toward the ink that the laser doesn’t burn the tissue — the energy instead collapses into a shockwave. The shockwave vibrates through the skin and causes the upper layer of skin to lift up and appear white, or to “frost.” Though painful, this effect usually lasts just a few seconds.