Hyaluronic acid is a kind of hyaluronic acid (HA), also known as uronic acid. Natural hyaluronic acid is a kind of macromolecular polysaccharide, which is a linear macromolecular polysaccharide with glucuronic acid -N- glucosamine acetate as disaccharide molecular unit. Its average molecular weight is between 6,543.8+10,000 and 6,543.8+10,000 daltons, and it exists in intercellular spaces. Originally used only for moisturizing, it has now been included in the ranks of wrinkle removal and plastic surgery. This plastic surgery technique is to inject hyaluronic acid, which is non-animal stable and cultured by bacterial fermentation, into wrinkles and depressions of dermis or parts that want to be full, to remove wrinkles and modify the face, which can immediately remove wrinkles and change appearance. Hyaluronic acid, which originally exists in the dermal tissue of human skin in the form of colloid, is responsible for storing water, increasing skin volume and making skin look full, plump and elastic. However, hyaluronic acid will disappear with age, making the skin lose its water storage capacity, gradually becoming dull, aging and forming fine wrinkles. Thanks to the progress of biotechnology, hyaluronic acid can be extracted from connective tissues of vertebrates, such as cockscomb, eyeball, umbilical cord and cartilage. In the past, hyaluronic acid was mostly extracted from animals, but now it is artificially synthesized, which avoids problems such as allergies and infections. Hyaluronic acid is mainly used in the field of medical beauty, and now it has greatly replaced collagen. Placenta and Botox. Botulinum toxin can remove wrinkles by blocking the transmission of information between nerves and muscles. Compared with chemical peeling and collagen injection, botulinum toxin wrinkle removal is indeed the most advanced wrinkle removal technology in the world. It has the advantages of little injury, no trauma, no influence on work, quick effect and so on. Just inject a needle of botulinum toxin into the wrinkles, and the wrinkles will gradually flatten out in 3 to 14 days. Botulinum toxin is not everything. After all, it is a toxin and has side effects. Botulinum toxin eliminates wrinkles by paralyzing muscles, so it occasionally produces adverse reactions such as headache, allergy, diplopia and unnatural expression. Compared with botulinum toxin, hyaluronic acid has less side effects, wide application range and convenient use. The effective time of botulinum toxin injection is 4 months to 6 months. To be effective for a long time, you need to inject it three or four times a year. Hyaluronic acid is only needed once every six months.