White pepper, or in fact all peppers contain capsaicin, a hot substance which generates heat. This fundamental property of pepper is utilized by using it in pain relieving gels and sprays. Under the impact of capsaicin, one feels the heat being generated in the affected area, due to which pain, resulting from spasms or sprains tends to lessen.
Due to the presence of capsaicin, pepper helps in burning the fats inside the body and thus helps in losing weight. It is the reason most weight loss medicines and solutions contain capsaicin in them.