Kojic acid soap is a type of soap that contains kojic acid as its active ingredient. Kojic acid is a natural substance that is produced by certain types of fungi. It is known to have skin lightening and brightening properties and is commonly used in cosmetic products.
Kojic acid soap is often used to lighten dark spots and hyperpigmentation on the skin. It works by inhibiting the production of melanin, the pigment that gives skin its color. This can help reduce the appearance of dark spots and even out skin tone.