According to The Book Menhadi

According to the book Menhadi Rang Rachi by Dr. Mahendra Bhanawat, mehndi has been used in India especially for its cooling effect. It was mixed with water and drunk as a method of therapy, although I do NOT suggest that you do that with the mehndi that you purchase. It is not a safe thing to do so don't risk it. It was also used in packs to help According to the book Menhadi Rang Rachi by Dr