Laser hair removal is a process by which the melanin in the hair follicle is targeted and neutralized with a concentrated beam of light (laser) or intense pulsed light (IPL) therapy. “This light energy is converted into heat, which permanently damages and destroys the hair follicles,” board-certified dermatologist Hadley King, MD, told us about laser hair removal.

The light actually targets hair that is in the active growth phase, also called the anagen phase. Once the hair has been “killed”, it will not grow back in the next growth cycle.

However, not all hairs in an area are in the same part of the growth cycle, as some are in catagen or telogen. This is why not all hair is effectively neutralized in one session, and successive treatments are required to be effective.

And as I mentioned, light also affects the melanin pigment in the hair. This means that some lasers and IPL are not suitable for those with darker skin, as the light beam may hit the skin and not the hair. This can cause damage and scarring. Always look for options that are considered safe and effective for those with darker skin tones (and if you have any questions about this, find a professional you trust who can help you).

This also means that these devices are not very effective on light or red hair, as the laser is unable to register the light pigment. Therefore, a home laser may not be worth your investment.

We discuss these caveats throughout the article, but this is an important caveat to mention right away.