The most important consideration with laser hair removal is the patient's skin type and hair color and the degree of contrast in color between the two. The differential absorption of melanin in the hair follicle and melanin in the skin epidermis determines the amount of laser energy that can be safely used. The ideal patient has light skin with black hair (i.e. a very sharp contrast with lots of pigment in the hair but very little pigment in the skin). A patient with very dark skin with white or grey hair would have little if any response to laser hair removal and they are not able to undergo laser hair removal.

Shorter laser light wavelengths, such as from the ruby laser with a wavelength of 694nm, and alexandrite laser @ 755nm, must be used with caution in darker skinned patients, because of the risk of pain, blistering, and hypopigmentation. Dark hair absorbs laser light better than blond or red hair, and usually responds better. However, most patients with blond or red hair also have lighter skin and this allows for the safe use of higher laser energies. No currently available device works well in patients with grey hair (canites) because of the absence of melanin.

An underlying cause for the excess hair, if present, should be corrected. These causes may include endocrine abnormalities and medication effect, including minoxidil, steroids, oral contraceptives, and some immunosuppressive agents.

Any dark skinned candidate will be the most likely have a bad outcome and need far more treatments than either of the other two skin types. Moreover, the darker the person’s skin the less beneficial their results will be. Darker skinned candidates also require a practitioner with greater skill and expertise to achieve maximum results. Darker skinned people seeking laser hair removal may find the best and safest results are achieved in a professional laser dermatology clinic with a fully qualified doctor who has experience of treating dark skin and understands the side effect risks.