Alpha Arbutin works by inhibiting melanin production, so it will prevent future hyperpigmentation. If you want to fade existent hyperpigmentation and have sensitive skin, Mandelic Acid might work and be gentle enough for sensitive skin. If you are not sure, ask Deciem Ambassadors at DECIEM's website and they will give you free personalized help I have both products and have been using the Alpha Arbutin 2% + HA daily for several months without much change, if any, in the appearance of the scars. I recently bought the Ascorbic Acid 8% + Alpha Arbutin 2% to try it out and it patch tested fine and seems to agree with my skin. Tranexamic Acid is safe to pair it with other known brightening ingredients such as Vitamin C, Vitamin E, Ferulic Acid, Hyaluronic Acid to maximise the benefits and improve the results. As for Alpha Arbutin, it inhibits the production of amino acid L-tyrosine which is essential for melanin production and melanosome maturation. Alpha Arbutin 2% + HA: Lightens dark spots without causing sun sensitivity, effective for all skin types including sensitive skin . Ascorbic Acid 8% + Alpha Arbutin 2%: Combines the benefits of Vitamin C and alpha arbutin for brightening skin and reducing hyperpigmentation . .

alpha arbutin or vitamin c first