Vitiligo is believed to be an autoimmune disorder that causes patches of skin to lose their color.  It occurs in about five percent of the human population regardless of race, but most commonly in dark-skinned people.  The two most common treatments are exposure to sunlight (or PUVA) or corticoster old drugs, but these are not always effective.

Oral doses of neem were tested at least one year on fifteen patients who had the disease.  They also applied a cream made up of several herbs to patched, which were then exposed to the sun.  After ninety days, 25 percent of the patients showed complete relief.  No adverse reactions were shown by any participants.  Those who stayed on the treatment the longest showed the most improvement.  The dosage was four grams of neem leaves three times a day, ideally taken before each meal.

Other studies showed that the internal use of neem leaves and bark were effective even without the cream.  It may be possible that neem oil applied to the affected areas could aid in the reversal of discoloration.