Hyaluronic acid, also known as hyaluronic acid, is an acidic mucopolysaccharide, which was first isolated from the vitreous humor of bull’s eye by Meyer, professor of ophthalmology at Columbia University in 1934. It has many important physiological functions in the body, such as lubricating joints, regulating the permeability of blood vessel walls, regulating the diffusion and operation of proteins, water and electrolytes, and promoting wound healing. Especially important is that hyaluronic acid has a special water retention effect and is the best moisturizing substance found in nature, which is known as the ideal natural moisturizing factor. Human skin contains a large amount of hyaluronic acid, and the skin maturation and aging process also changes with the content and metabolism of hyaluronic acid, which can improve the skin nutrient metabolism, make the skin soft, smooth, remove wrinkles, increase elasticity and prevent aging. It has good solubility with human tissue, no rejection and allergic reaction, easy and safe to inject. It can not only be used to fill wrinkles, depressed scars after acne, etc., but also can play a role that can moisturize and hydrate, with remarkable effects. The main indications are facial fillers, which can fill facial wrinkles, such as head lines, frown lines, tear trough lines, crow’s feet, nasolabial folds (decree lines), apple lines, lip lines, neck lines, etc.; it can also be used for facial contour shaping, such as nose augmentation, chin augmentation, earlobe augmentation, temporal augmentation, temple augmentation, etc.; in addition, it can also be used to fill depressed scars. The effect of Restylane injection can generally be maintained for 6-12 months. Clinical experience has confirmed that re-injection can effectively extend the duration of the treatment effect. If combined with Botox, the maintenance time can be extended. Precautions before injection of Restylane: To prevent bleeding and swelling at the injection site, avoid taking aspirin, non-steroidal anti-inflammatory drugs, Kanye Lena and high doses of vitamin E for 3-4 days before injection, and wash any cosmetics and skin care products on the injection site with cold water before injection. The use of surface anesthetics or local ice packs before injection can reduce the pain during the injection process. Pregnant women and breastfeeding patients should not undergo Restylane injections; patients with skin diseases, a history of skin allergies, or skin prone to bruising or bleeding, and patients with autoimmune diseases should be carefully considered before receiving Restylane treatment. If the patient has suffered from herpes simplex, the injection needle piercing process may re-trigger herpes simplex, and appropriate application of antiviral medication may reduce this risk. Patients who have undergone laser or chemical peel treatment need to wait until the local skin has completely recovered (usually 4-6 weeks) before undergoing treatment with Restylane. Reglan fillers should not be used again in areas that have already received permanent filler treatment. Precautions after injection of Restylane: within 24 hours after injection, do not use cosmetics on the whole face, do not get wet or contaminated; within 48 hours after injection, do not massage or rub the injection site unless directed by a physician; after injection, until the local redness and swelling subsides, do not expose the injection site to a high temperature environment to prevent inflammatory reactions, and do not expose it to an extremely cold environment, and avoid applying ice to the injection site or Avoid applying ice or heat to the injection site. After receiving the injection, it is also necessary to wait until the local redness and swelling have completely subsided and the skin has returned to normal (about 4 weeks) before receiving laser or chemical peel treatment. For best results, supplemental injections may be required 4 weeks after the injection. Supplemental injections usually require a smaller dose than regular injections, and they are effective in prolonging the duration of the treatment effect. Common complications of Restylane: A small number of patients may experience injection-related reactions after a Restylane series injection. These reactions include redness, swelling, pain, itching, bruising or tenderness at the injection site and are usually mild to moderate and resolve on their own within a few days after the injection. These reactions include redness, swelling, tenderness, and palpability of the implant at the injection site, which may occur shortly after injection or with a delay of 2-4 weeks, are mild to moderate, and are self-limiting, lasting an average of 2 weeks. Patients with significant reactions may be managed with short-term oral steroids. Other serious adverse reactions include granuloma formation, injection site necrosis, and injection site hyperpigmentation. If too much is injected locally, hyaluronidase can be used to degrade it.