In recent years, the incidence of melasma has been increasing year by year due to factors such as living habits and mental stress, making melasma treatment a common concern in today’s medical and cosmetic industries. What are the current treatment methods for melasma? Western medical treatment: Western medical treatment for melasma aims to inhibit melanocyte proliferation, prevent melanin particles from forming, accelerate melanin particles degradation and reduce melanocyte activity, etc. 1. Systemic treatment Vitamin C, E and their derivatives: Research shows that vitamin C can inhibit the oxidation of dopamine, inhibit the formation of melanin, and reduce the formed melanin in the skin into colorless substances and water-soluble gums, while vitamin E is lipid-soluble and can play the role of scavenging free radicals in lipids, which has a synergistic effect with vitamin C. Glutathione: Glutathione and vitamin C have a synergistic effect, playing the role of antioxidant, inhibiting tyrosinase activity and dopamine oxidation, inhibiting melanin vesicle formation and promoting its decomposition, etc. 2.Topical treatment All-trans retinoic acid: retinoic acid has the function of inhibiting the tyrosinase activity of melanocytes, preventing the transfer of melanin to keratin-forming cells, regulating the function of melanocytes and reducing melanin formation. Hydroquinone: Hydroquinone hinders melanin synthesis by competitively inhibiting tyrosinase activity, promotes its degradation, and inhibits melanocyte DNA and RNA synthesis. Its efficacy is related to the concentration, matrix and chemical stability of the preparation, and is now generally considered to be best at a concentration of 3% alone. Arbutin: Arbutin is a naturally occurring form of hydroquinone, and its mechanism of action is similar to that of hydroquinone, but its efficacy is related to the duration of action and the amount of drug absorbed by the local skin. Physical therapy: Laser: In the past two years, laser technology has been more often tried for melasma treatment, which plays a therapeutic role by destroying the formed melanin granules and melanin vesicles, reducing the synthesis of melanin and its transfer to keratin-forming cells. Intense pulsed light: Intense pulsed light penetrates the skin and is preferentially absorbed by pigment groups in tissues, causing the destruction and decomposition of pigment groups and pigment cells without destroying normal skin; at the same time, it acts on skin tissues to produce photothermal and photochemical effects, causing the deep collagen fibers and elastic fibers to rearrange and restore elasticity, and enhancing vascular function and improving circulation. Photorejuvenation: Photorejuvenation instrument for melasma treatment uses the principle of selective photothermolysis, strong pulsed light penetrates the skin, so that pigment particles in the tissue are absorbed first, and electric light energy is converted into heat energy to destroy and decompose pigment particles, while light acts on the collagen layer of the skin to rearrange and combine the collagen fibers and elastic fibers in the deeper layer, restoring skin elasticity and luster.