Panthenol (sometimes referred to as pro-vitamin B5) is a popular humectant in personal care products due to its ability to attract and retain moisture. When applied topically, it is converted to pantothenic acid, which is a naturally occurring substance in the body.
Studies show that 1% panthenol rapidly increases skin hydration while decreasing transepidermal water loss (the amount of water that evaporates through the skin). The overall result is an improvement in the way the skin feels and looks, including a smoother appearance.
Research also shows promise in panthenol's ability to reduce sensitivity-induced redness in the skin.
Topically applied panthenol in amounts between 1-5% has been reported to aid in healing and barrier repair.
It is important to clarify that although panthenol is the alcohol derivative of pantothenic acid, it is a completely gentle and non-drying form of alcohol, unlike SD or denatured alcohol, which are known to be harmful to the skin.
Panthenol is water-soluble and "plays well" with many different types of ingredients, making it easy to formulate with moisturizers, serums, toners, etc. It is also widely used in hair care products and can be found in makeup products such as powders, mascara and lipstick.
As a raw material, two forms of panthenol can be incorporated into product formulas for personal care: D-panthenol is a viscous oil, and DL-panthenol comes in the form of a white, crystalline powder.
According to the 2018 Cosmetic Ingredient Review assessment, the highest reported concentration of panthenol in a personal care product was 5.3%, which was considered safe for its use. https://www.paulaschoice.com/ingredient-dictionary/ingredient-panthenol.html?q=Panthenol&fdid=ingredients