The answer to this question relies a great deal on understanding some key facts about how your body hair grows, and how laser hair removal actually works.

How Does Hair Grow?

Hair grows from structures called follicles below your skin. The root grows in the follicle, and the section of the hair that can be seen above your skin is called the "shaft" of the hair. Your body hair grows in a cyclic way. At any one time, the hair in certain follicles will be actively growing; other hairs will be dormant, and yet others will be in the process of shedding.

How Does Laser Hair Removal Work?

Reduction of hair growth or even permanent removal is now possible for most skin and hair types. Laser hair reduction therapy works by targeting hair follicles under your skin. It is possible for the laser rays to hone in on your hair follicles because of the melanin these cells contain, which makes them darker than the surrounding tissues.

However, the result is that the efficacy of laser hair removal treatment is impacted by the contrast in color between your hair follicles and your skin. That is to say, it works most effectively if you have very light skin and very dark hair - where there is a strong contrast between the darkness of your hair follicles and the paleness of your surrounding skin tissues.

Even in ideal patients, however, the lasers do not do away with all of your hair. Why not? Due to the fact that the lasers can only target actively growing hairs. As we learned earlier, only a certain proportion of your body hair in any one area will be currently growing. This is the reason why laser hair removal sessions are typically spaced several weeks apart - so that different follicles will be active at your next session, and can be effectively "zapped".

Conclusion

Because of the mechanism by which laser hair removal works, while it may disable a significant proportion of the follicles it will not cause a 100% stoppage in all body hair growth in the treated area. However, an 80% reduction in hair is entirely possible - permanent laser hair removal is a truly viable solution for undesirable hair growth.