Xonil 5% w/v Solution is used in the treatment of hair growth and male pattern baldness. Xonil 5% w/v Solution has no effect in receding hairline and baldness at the front part of the scalp. About 2 percent of Xonil 5% w/v Solution is used in women who have thinning hair. Xonil 5% w/v Solution needs to be applied topically on the skin. It falls under a category of drugs known as vasodilators.