The Science of Moisturizers: How They Work, Who They’re For, and How to Use Them

Spencer Hodgson

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May 28, 2022

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A moisturizer is a skincare product designed to hydrate the skin, strengthen the skin barrier, and prevent moisture loss, keeping skin soft, smooth, and healthy.

Types of Moisturizers

Lotions – Light, water-based; best for normal to oily skin.

Creams – Balanced oil–water; suitable for normal to dry skin.

Ointments/Balms – Heavy, oil-based; ideal for very dry or damaged skin.

Gels – Oil-free, fast absorbing; good for oily or acne-prone skin.

Moisturizers work through three key components:

1. Humectants

Mechanism: Attract and bind water into the stratum corneum

Result: Increased hydration and skin plumpness

2. Emollients

Mechanism: Fill gaps between skin cells with lipids

Result: Smooth, soft, and flexible skin

3. Occlusives

Mechanism: Form a protective film on the skin surface

Result: Reduced water loss (TEWL) and moisture retention

Mechanism Of Action:

Step 1:

Application on Skin The moisturizer is applied to clean, slightly damp skin, allowing better spread and penetration.

Step 2:

Humectant Action (Hydration) Humectants attract and bind water from the environment or deeper skin layers into the stratum corneum, increasing skin water content.

Step 3:

Emollient Action (Barrier Repair & Smoothness) Emollients fill the gaps between dry, damaged skin cells with lipids, restoring the skin barrier and making the surface smooth and flexible.

Step 4:

Occlusive Action (Moisture Locking) Occlusives form a thin protective film over the skin, reducing transepidermal water loss (TEWL) and sealing in the absorbed moisture.

Step 5:

Result (Healthy Skin) Skin remains hydrated, soft, protected, and resilient against environmental damage.

How to Properly Use a Moisturizer

1. Cleanse skin gently

2. Apply moisturizer on slightly damp skin

3. Use twice daily (morning & night)

4. Choose formula based on skin type & climate

In Summary

Moisturizers are not one-size-fits-all. From humectants and emollients to occlusives, understanding what you’re using and how you apply it makes all the difference.