Since everyone has different types of skin and hair, the answer to "How long does laser hair removal last?" varies from person to person. Laser hair removal tends to work best on people with dark hair and light skin.
Laser hair removal may or may not be permanent. Most of the unwanted body hair is reduced, but since there are thousands of hair follicles on the skin, some hair may grow back in a few months or even years after treatment. How long the results last depends on a person's skin and hair type.
Most people will see at least an 80% reduction in density. The hair re-growth is also usually thinner, finer and lighter in color compared to how it was at the start of the treatments.
Not all hair strands are in the same growth stage at the same time. Multiple laser treatments are necessary to burn the hair follicles since the treatments only work when they're in their mature stage. Due to the high number of follicles needing to be 'zapped', more than a single session is required to deaden as many as possible.
In addition, the body is constantly rejuvenating itself and some follicles that were only marginally affected could start regrowing as a thinner hair fiber a few months later. Talk to your clinician about follow-up treatments that may be necessary since this obviously adds to the overall cost.
The good news is that in the interim, it will not be necessary to constantly shave, pluck or chemically rid yourself of unwanted hair.
Go to a reputable laser hair treatment clinic or salon and ask an experienced clinician, "How long does laser hair removal last?" They will be able to determine how effective the laser for hair removal will be for your skin and hair type.