Ceramides (emollient / humectant)

**Ceramides** are lipid molecules that act as the **mortar between the bricks** of your skin cells—essential for maintaining a **strong, hydrated, and resilient skin barrier**.

### 🌿 **What They Do**:
– **Barrier Builders**: Ceramides make up **30–50% of the stratum corneum lipids**, sealing in moisture and keeping out irritants.
– **Moisture Lockers**: They prevent **transepidermal water loss (TEWL)**, keeping skin plump and hydrated.
– **Soothers & Protectors**: Help calm **inflammation, dryness, and sensitivity**, especially in conditions like **eczema and psoriasis**.
– **Anti-Aging Allies**: By reinforcing the barrier, they reduce **fine lines and dullness** caused by dehydration.

### 🧴 **Where You’ll Find Them**:
– **Moisturizers & barrier creams**
– **Cleansers & toners for sensitive skin**
– **Eye creams & anti-aging serums**
– **Hair conditioners & scalp treatments**

### 🧬 **Types of Ceramides**:
There are **12+ identified types**, often labeled as:
– **Ceramide NP (3)**
– **Ceramide AP (6-II)**
– **Ceramide EOP (9)**
– **Phytosphingosine & Sphingosine** (precursors)

These differ in their **fatty acid chain lengths and head groups**, influencing how they behave in the skin’s lipid matrix.

### 🛡️ **Formulation Tips**:
– Often paired with **cholesterol and fatty acids** in a **3:1:1 ratio** to mimic the skin’s natural lipid structure.
– Used at **0.5–5%**, depending on the product.
– **Synthetic ceramides** (pseudoceramides) are more stable and widely used in cosmetics.