Ceramide 神經酰胺（分子釘；賽洛美）
神經酰胺，是存在於人體皮膚角質層的細胞間脂質，是角質層脂質中最重要且比例最高的成分，約佔細胞間脂質的40~55%。
神經酰胺的主要功用有：
1.角質層內重要組成，使肌膚維持柔軟平滑，更具彈性及張力。
2.皮膚保水性能的關鍵成份：神經酰胺會在皮膚上形成薄膜，能防止水分蒸發，維持並調節表皮的含水量。
3.參與細胞間接合作用的物質，亦即表皮障壁作用之最主要成份，可強化肌膚本身防禦外界污染的能力。
年紀增加時，神經酰胺的分泌量會減少，造成角質層無法保留水分、養分，使皮膚產生乾燥、粗裂。而經由外部擦拭補充神經酰胺，能增加角質細胞的粘合力，減低水分的散失，而達到保濕的效果。
分子釘-Ceramide
Ceramide is intercellular lipids present in the stratum of human skin. It is a the highest proportion ingredient in cuticle lipid composition. Around 40~50% in intercellular lipid.
1.It is an important component of the stratum corneum. Keeps skin soft and smooth. More elastic and tension.
2.It is the key ingredient of the skins water retention properties. A film will form on the skin by Ceramide. Prevent water evaporation. Maintain and adjust the water content of the epidermis.3.Substances involved in the binding between cells. It is the most important component of epidermal barrier. It also can strengthen the skins ability to defend against eternal pollution.
The amount of secretion will decrease when the age increases. Cause keratin to be unable to retain moisture and nutrients. The skin will become dry and cracked. Replenish by wiping the surface will increase the adhesion of keratinocytes. It can reduced water loss and to achieve moisturizing.