The Inkey List Mandelic Acid Treatment. Reduces Hyperpigmentation and Discoloration .5 Oz. Targeted formula that reduces the look of hyperpigmentation and discoloration left behind by blemishes. Mandelic Acid 10%: Reduces the appearance of dark spots hyperpigmentation and post-blemish marks. Glycerin 2%: Hydrates skin and draws in moisture. Encapsulated Retinol 0.1%: Helps fade the appearance of dark spots and discoloration.