Hyaluronic acid (HA) is a naturally occurring polysaccharide found in the skin that helps to retain moisture and keep the skin hydrated. It is commonly used in skincare products as a humectant due to its ability to hold up to 1000 times its weight in water. In addition to hydration, HA has been shown to improve skin texture and smoothness, reduce the appearance of fine lines and wrinkles, and promote skin elasticity. HA can also enhance the effectiveness of other active ingredients in skincare products. It is found in a variety of skincare products, including serums, moisturizers, and injectable fillers. It is generally considered safe for all skin types and can be used daily to improve overall skin health and appearance. However, individuals with sensitive skin may want to patch test the product before using it on a larger scale.
"The Effect of Topically Applied Hyaluronic Acid on Skin Moisture and Mechanical Properties" - This study, published in the International Journal of Cosmetic Science in 2009, found that topical application of HA increased skin hydration and improved skin elasticity.
"A Double-Blind, Randomized, Placebo-Controlled Study on the Effect of Topical Hyaluronic Acid on Skin Hydration and Aging Signs" - This study, published in the Journal of Drugs in Dermatology in 2011, found that topical HA improved skin hydration and reduced the appearance of fine lines and wrinkles.
"The Use of Hyaluronic Acid Fillers in Facial Rejuvenation" - This review article, published in the Journal of the American Academy of Dermatology in 2008, summarizes the current use of HA fillers in cosmetic dermatology and highlights the safety and efficacy of these products.
These are just a few examples of the many studies that have been conducted on the use of HA in skincare. You may also want to search for more recent studies in relevant scientific journals for the most up-to-date information.