SBT 的涂抹次序说明：透明质酸等大分子多在表层成膜锁水，而神经酰胺、胆固醇、脂肪酸等结构性脂质才是填补灰浆的角色。

所以「用了玻尿酸脸还是干、还是刺痛」很常见——水分留不住，问题往往在灰浆而非砖体。

正确的搭配是：亲水保湿剂先润泽角质层，结构性脂质补充细胞间脂质，活性物再进入更深层。

If skin stays dry and stings despite hyaluronic acid, the problem is often the mortar, not the bricks — water simply is not retained.

Correct pairing: humectants hydrate the corneocytes first, structural lipids refill the intercellular space, then actives go deeper.