I don't see any scientific studies supporting the claim of improvement in skin tone, color, or texture. However, many people feel that a product has worked, so I have included this page as part of the scientific research to back up these claims.
If you are a health professional, this page may be very helpful. This page contains a list of scientific studies that demonstrate the effectiveness of the products. I hope that this list will be helpful to you and to your clients, because many of the products contain ingredients that have nothing to do with health, and they may be dangerous if used improperly. This page does not provide you with all the products on the market. It is not possible to buy all of them because the manufacturers sell their products to different companies. If you buy a particular product, it may be only one that is effective. You may also find a very effective product that you need to use for a very long time. I have included many products that have not been studied. However, I can say that most of the products shown here are very good. There are some products that are not effective.