It depends on the individual. You can look at the information. I got it from somewhere else. Open classification of fruit acids: The Catalogue of Fruit Acids for Skin Care and Beauty summarizes the concentration, pH value, usage and precautions of fruit acids. The indication of fruit acid skin changing is the preparation before skin changing and the matters needing attention after skin changing. Glycolic acid extracted from sugarcane is the most commonly used. The role of fruit acid is to remove the hyperkeratotic stratum corneum, help patients remove the damaged outer skin and stimulate the growth of new cells. It can be used for treating acne, improving the skin with coarse pores, aging, dryness, roughness and dullness, and can also dilute epidermal pigmentation and improve wrinkles. Low concentration of fruit acid (< 20%) can be used for maintenance, and high concentration (20%-70%) can be used for skin change. The concentration of fruit acid is poor in dermatology: very low concentration of fruit acid only has moisturizing effect. When the concentration is slightly higher, exfoliation can destroy the connection between stratum corneum cells and promote skin metabolism. At a higher concentration, it is more destructive, reaching the dermal tissue and can be used for chemical skin change. Generally speaking, the higher the concentration, the more obvious the effect, but the probability of side effects is relatively increased. According to different concentrations, the effects of fruit acid on the skin are different: 1, and the low concentration of fruit acid (less than 10%): fruit acid can reduce the cohesion between epidermal keratinocytes, remove aged keratin, improve roughness and dullness, and condition the skin. 2. Medium concentration of fruit acid (10%-30%): the fruit acid effect can reach the dermal tissue, and it has a good effect on acne, fading dark spots and smoothing wrinkles. 3. High concentration of fruit acid (above 30%): It has quite strong penetration, can peel off aged cutin at one time, and accelerate the effect of removing spots and wrinkles. However, high concentration of fruit acid is skin-changing, and it is best to find a professional doctor for treatment. The PH value of fruit acid Fruit acid is a weak acid, and its efficacy depends on its pH value in addition to its concentration. Acidic environment is conducive to the development and preservation of fruit acid. In alkaline environment, fruit acid will dissociate and lose its function. For example, the concentration of AHA is as high as 15%, but in the solution with PH greater than 5, most acid molecules have dissociated, and people lose the activity of acid. In fruit acid products, stable equilibrium is more important than the adjustment of pH value by the concentration of fruit acid in slow equilibrium solution system. According to research, when the PH value is in the acidic range of 2.5-3, the effect of fruit acid is the best, but the irritation also increases. At present, the concentration of fruit acid in skin care products in cosmetics counters is below 5%, and the PH value is above 3. The efficacy can only focus on exfoliation and moisturizing, but it has no obvious effect on wrinkle removal and whitening. Concept of free acid: The so-called free acid is an acid that does not dissociate in solution. As far as fruit acid is concerned, it is also fruit acid that really works. All fruit acids are weak acids, and some will dissociate in aqueous solution. What really matters is the undissociated free acid. The usage method of fruit acid is 1, and the experiment is started from low concentration (1-4%). If your skin is seriously damaged, such as sunburn or allergy, you need to give your skin a repair process. You can continue to use the soothing and moisturizing mask for three days to adjust your skin to a healthier state. 3. Within 3-7 days after starting to use, some people will have peeling and serious oil production, so don't worry. After the skin adapts, it will make the skin's water storage capacity stronger. 4. Pay more attention to sun protection during the use of fruit acid. 5. When using fruit acid for skin care, it is not advisable to use other exfoliating products, do not rub the skin at will, and avoid using cosmetics containing acidic ingredients such as fruit acid and salicylic acid. 6. Wash your face, use emulsion for 20 minutes, and then use fruit acid products. 7. Wipe the T-shaped part first, then extend it to the face, wipe it from the thick stratum corneum to the thin one, and finally wipe the eyes and lips. 8. You can use emulsion to neutralize high-concentration fruit acid products. 9. Use it once a week as needed. Not suitable for patients with severe allergic skin and dermatological treatment. 10, winter and summer are the best time to use fruit acid. Matters needing attention in the use of fruit acid 1, fruit acid itself can exfoliate, so you don't need to use exfoliating products, steam your face or massage excessively, so as not to damage your skin. Wash your face as gently as possible so as not to irritate your skin. High concentration of fruit acid, A acid and vitamin C are all products with low PH value, so it is not recommended to use them at the same time. 2. When using fruit acid, because the cuticle is thin, the skin may be sensitive to some external stimuli, such as sun exposure, wind blowing and some cosmetics containing alcohol and exfoliating ingredients. Need to add some protective measures, such as the use of moisturizing agent, repair ointment, etc. Although fruit acid is not as sensitive as fruit acid, it can be used in the morning and evening, but it is easy to get sunburned without sunscreen after exfoliation. Therefore, you must pay attention to sun protection when rubbing fruit acid during the day, and try not to let your skin be stimulated by the sun. 3. If the skin has uncomfortable symptoms such as tingling, redness, itching and peeling, you should stop using fruit acid immediately. You can apply cold water to your face 10-20 minutes to calm it down, and use repair cream to increase moisturizing and maintenance. If it is serious, you can go to the hospital and let the doctor treat it with repair cream. When you use it again, you should start with a low concentration, and then gradually increase the concentration and use times. After a period of time, it will gradually adapt to the increase of tolerance. 4, skin sensitive person before use can do patch test, or daub on the inside of the arm, no stimulation before use. Avoid mucous membranes and eyes when using, and reduce the dosage when using because the skin near the mouth and lips is weak. Although fruit acid is widely used and there are many products on the market, people who are eager for beauty should not only fully understand fruit acid, but also seek help from professional doctors, so that experts can create the most perfect solution for you. This is what smart people should know. Indications for skin replacement with fruit acid There are many indications for skin replacement with fruit acid. The most common thing is skin rejuvenation, including removing surface skin wrinkles and improving skin appearance. It can treat pigmentation, including liver spots and sunburn, which are common indications, but it is best to use it with freckle-removing products, and the effect is better. Fruit acid can remove aged keratin, prevent keratin proliferation from blocking capillary pores, and treat acne. Epidermal keratinocyte hyperplasia, verruca plana and acne scar caused by light damage can also be treated with fruit acid for skin replacement. In addition, fruit acid can also increase the effect of local application of drugs, such as increasing the efficacy of steroids on psoriasis and chronic lichen dermatitis, and increasing the efficacy of antifungal drugs on mold infection. Acne treatment: acne, acne, blackheads, pustules and large pores. Treatment of light spots: spots, brown spots, acne marks and dull skin. Anti-aging treatment: dark yellow skin aging, fine lines, keratin accumulation. Effect of fruit acid rejuvenation on skin: Fruit acid rejuvenation can exfoliate and remove aged epidermis, making skin look delicate and smooth. The main function of exfoliation is that fruit acid can reduce the adhesion between keratinocytes. However, the long-term effects of fruit acid on epidermis and dermis need to be continuously maintained at a low concentration and repeatedly changed skin. The exfoliating effect of fruit acid will gradually weaken as the skin adapts to fruit acid. As a result, the stratum corneum becomes regular and the epidermal cell layer becomes thicker. The acidity (pH value) of fruit acid determines its effect on skin and its ability to change skin acidity. The ideal acidity of fruit acid is between 2.8 and 4.8, which is the most effective for epidermis regeneration. Preparation before skin changing When you decide to use fruit acid for skin changing, in order to adapt your skin to high concentration of fruit acid and achieve the best effect, you should start the following daily skin care work: one to two weeks before skin changing, start using fruit acid maintenance cream (or lotion or gel), and use it once after washing your face at night to adapt your face to fruit acid. Patients with dark spots should use sunscreen (SPF 15 or above) every morning to avoid sun damage, and then use it in the sun at noon. One week before changing skin, you should stop the following behaviors: facial beauty or perm, hair dyeing, shaving and hair removal. Excessive swimming on the face with scrub and acidic products. Before changing skin for sunburn, you need to tell your doctor whether you have the following symptoms: skin allergy or immune diseases, facial skin diseases (such as eczema and allergic dermatitis), excessive sensitivity to sunlight, smoking, facial injury, viral infection (such as lip rash and verruca plana), taking drugs on the day of changing skin, and being allergic to alcohol. If you have any questions about the above points, please consult your doctor. Precautions after skin changing After skin changing, it takes about a few days to a week for your skin to completely return to normal. During this recovery period, you may have the following symptoms: slight irritation, itching, burning sensation, slight pain, facial tightness, peeling or slight scar. These symptoms will gradually disappear over time (about a week) until they return to normal. If the skin is swollen, please ice it within 24~48 hours after changing the skin. Following the following steps will help you speed up the process of skin regeneration: 1. Wash your face with clean water 1-7 days every day after changing skin, pat it dry with a towel (avoid rubbing your skin hard), and use ointment or nourishing cream as directed by your doctor after washing your face (once in the morning and once in the evening) until your skin returns to normal. 2. After about 1-7 days, when the skin returns to normal, you can stop using ointment or nutritional cream and start to gently clean your face with cleaning products (but don't wipe it with a sponge or towel, pat it dry gently to avoid irritating the skin); And you can resume using the original fruit acid maintenance cream, fruit acid emulsion or fruit acid gel once a night. 3. Before the skin returns to normal, absolutely avoid sun exposure (don't use sunscreen lotion to avoid greater irritation to the skin, and don't wear a hat to avoid leaving scars on the brim). After returning to normal, if you want to go out, it is best to use sunscreen lotion every morning to avoid pigmentation caused by ultraviolet rays. To avoid scar formation, please don't shave, scab, itch, apply your face, wear a hat, etc. Before the skin returns to normal. If you think this entry needs to be improved, and you need to add new content or modify the wrong content, please edit the entry reference:

1./special14-2. ASP Contributor (* * 8): Wei Zhenjue Su Bei Hanwang, Bing Bing Supreme, An Jielinda, goldmark, Goddog, Yun of Snow and Ice, cloverbinbin and cielpurple are all mentioned in the following entries: red wine honey mask, moisturizing agent, and CIEL purple. Rose hip oil, blackheads, soft pears, skin rejuvenation, cosmetic allergies, melon seeds, la roche-posay soothing spray, biotherm men's fat-clearing balance moisturizing milk, L 'Oré al super moisturizing hair cream, strawberry beauty, fruit mask, acne mask, cherry beauty, L 'Oré al perfect slimming scrub value-added set, Helena whitening essence, biotherm Cocoa firming gel, cosmetics, hand cream, night cream, shampoo and so on.

tartaric acid