Amazon.com: Remedy for Dark Spots Advanced Discoloration Correcting Serum Retinol, Kojic Acid, Tranexamic Acid, Niacinamide, Mandelic Acid Fragrance Free, Sensitive Skin By Dermatologist Dr. Shah 1fl oz : Thiamidol is a revolutionary and unique active ingredient that reduces the dark marks and pigment spots also known as hyperpigmentation, a common skin concern. Acting at the root cause of hyperpigmentation, it Glutathione or L Glutathione: What is Better for Skin? I layer multiple brightening ingredients to keep my skin tone even and fade dark spots. In the mornings, I use a vitamin C antioxidant serum + thiamidol, and (pre pregnancy) a retinoid at