Recently, the network hotly debated aspirin can remove dandruff and can make the skin whitening recipes are many netizens competing reproduced. Do these recipes really work wonders? According to some netizens, using aspirin as a mask feels like face pain, but the skin condition has not improved. Some netizens also said, with this method to dandruff and did not achieve significant results. Can aspirin be used for cosmetic purposes or not? Humans discovered the medicinal properties of willow plant extracts (natural salicylic acid) very early. Ancient Sumerian clay tablets contain references to willow leaves for the treatment of arthritis, and in 1897, German chemist Felix Hoffmann added an acetyl group to the salicylic acid molecule and invented acetylsalicylic acid, now known as aspirin. Aspirin is stable in dry environments, but slowly breaks down into salicylic acid and acetic acid in humid environments. Be careful when using salicylic acid for cosmetic purposes Salicylic acid is a commonly used topical drug in dermatology. Concentration of 3% to 6% of the salicylic acid can be exfoliated, used to treat a variety of chronic skin diseases, such as fungal skin disease (ringworm), cracked hands and feet, psoriasis and chronic dermatitis. Concentrations of salicylic acid higher than 6% are destructive to skin tissue. Higher concentrations (20% to 40%) of salicylic acid, on the other hand, are corrosive to the skin and are mostly used to treat corns, calluses, and common warts. In 1997, Dr. Kligman published a paper in the “American Journal of Dermatology” that the concentration of 30% salicylic acid as a chemical peeling agent, its lightening of pigmentation, pore size, remove fine wrinkles and other improvements in the effect of skin aging and the concentration of 70% of the effect of fruit acid peels the same. Because salicylic acid has the function of exfoliating, cleaning pores, high safety, and lower irritation to the skin than fruit acid, thus becoming the favorite of beauty products, in the field of beauty and anti-aging set off a small ripple. The use of salicylic acid should strengthen skin moisturizing Salicylic acid has a strong exfoliating effect, but excessive exfoliation will lead to weakening of the skin’s barrier function, can appear erythema, itching, tingling and other signs of skin irritation, so the use of salicylic acid concentration can not exceed the safe range, while the need to strengthen the skin’s moisturizing repair. In addition, contact with eyes, face, reproductive organs and mucous membranes should be avoided. A small number of people will experience an allergic reaction to salicylic acid, and these people are not suitable for using salicylic acid products in any concentration. As high concentration of salicylic acid is harmful to the skin, according to China’s “Hygienic Standard for Cosmetics” (2007 edition), the limiting concentration of salicylic acid in skin care products as well as facial cleansers is 2%, and the limiting concentration of salicylic acid in shampoos is 3%. 30% salicylic acid can be used for chemical peeling, which belongs to the category of medical cosmetology, but it must be operated by experienced doctors, and it should not be used by oneself, nor be carried out in informal beauty salons, so as to avoid causing unnecessary damage to the skin. Do not use it on your own or in an unofficial beauty parlor to avoid unnecessary harm.