skin-identical ingredient

Really nice ingredients that can be found in the skin or mimic the things that can be found in the skin naturally. They have two big groups:

NMFs (Natural Moisturizing Factor): things that can be found inside the keratinocytes (skin cells) and help our skin to bind water. Glycerin or hyaluronic acid are famous NMFs. They are super-duper important in keeping the skin nicely hydrated.
SC (Stratum Corneum - the outer layer of the skin) Lipids: between the skin cells there is a goopy stuff called the extracellular matrix. It consists mainly of lipids and is super-duper important in having a healthy skin barrier. Ceramides, cholesterol, and fatty acids are important SC lipids.

Be it an NMF or some lipid, it's always nice to spot skin-identical ingredients on an ingredient list. :)

Acetyl Glucosamine Alanine Arginine Aspartic Acid Ceramide Ceramide AP Ceramide EOP Ceramide NG Ceramide NP Cholesterol Collagen Amino Acids Diglycerin Glycerin Glycine Helianthus Annuus Seed Oil Unsaponifiables Histidine Hyaluronic Acid Hydroxypalmitoyl Sphinganine Hydroxypropyl Bispalmitamide MEA Isoleucine Jojoba Oil/Macadamia Seed Oil Esters Lacto-Ceramides Linoleic Acid Linolenic Acid Palmitic Acid Pca Phenylalanine Phospholipids Phytosphingosine Phytosteryl Macadamiate Proline Serine Sodium Chondroitin Sulfate Sodium Hyaluronate Sodium Hyaluronate Crosspolymer Sodium PCA Squalane Squalene Threonine Urea Valine