A ceramide is a natural fat molecule found in the stratum corneum, the outermost layer of the skin, and makes up roughly half of the skin barrier. It sits between epidermal cells, acting as a “mortar” that holds them together. This preserves the integrity of the skin's surface. It keeps moisture locked in and forms a defensive shield against external factors.
When ceramide levels fall, the skin becomes dry, tight, sensitive and prone to redness. Ceramide levels are known to decrease in conditions such as atopic dermatitis, rosacea and ageing. For this reason, ceramide is one of the most important ingredients in barrier-repairing and moisturising products.
Oral Ceramides
Oral ceramide supplements have been a topic of discussion in recent years. Oral ceramides are plant-derived lipid complexes. After being absorbed in the gut, they're thought to indirectly support epidermal lipid synthesis. Clinical studies have observed that regular use over 4–8 weeks reduces transepidermal water loss and increases hydration in the skin. However, their effect is neither as fast nor as strong as topical preparations. Rather than being considered a standalone treatment, they can be considered a supportive measure in suitable patients.