Moisturizers vs. Emollients: Clarifying the Difference

These substances form a hydrophobic barrier on the surface of the skin to prevent transepidermal water loss (TEWL). Occlusives are usually oily substances, and their sources include animals, plants, minerals and synthetics.

• Animal occlusives: such as lanolin, beeswax, squalane, etc.
• Plant occlusives: such as olive oil, coconut oil, jojoba oil, carnauba wax, candelilla wax, etc.
• Mineral occlusives: such as vaseline, paraffin oil, mineral oil, etc.
• Silicone occlusives: such as dimethicone, cyclomethicone, etc.
• Other occlusives: There are also cetyl alcohol, stearic acid or their fatty alcohol forms, and others include ceramides, phospholipids, sterols, etc.

These hygroscopic substances attract water from the dermis (lower skin layer) and the surrounding environment, drawing it into the stratum corneum. Due to the strong promotion in the cosmetics industry in recent years, hygroscopic ingredients may be the ingredients you are most familiar with, such as:

• Hyaluronic Acid: Known for its exceptional water-holding capacity, it can attract and retain a significant amount of moisture.
• Glycerin: A highly effective humectant that draws water from the air and the deeper layers of the skin.
• Urea: In addition to its moisturizing properties, urea also helps to exfoliate the skin.
• Panthenol (Vitamin B5): A humectant that also promotes skin healing and reduces inflammation.
• Sodium pyrrolidone carboxylate (Sodium PCA): A natural moisturizing factor (NMF) found in the skin, it helps to maintain optimal hydration levels.
• Propylene Glycol: A versatile humectant that also acts as a solvent and a penetration enhancer.
• Sodium Lactate: Another NMF that helps to regulate skin pH and improve hydration.
• Sorbitol: A sugar alcohol that attracts and retains moisture, providing long-lasting hydration.
• Gelatin: A protein-based humectant that also helps to improve skin texture and firmness.

Emollients are mainly composed of lipid ingredients, and their main function is to soften and smooth the skin. Emollients can improve skin texture and elasticity by filling the gaps between skin cells with lipids, while also reducing roughness and flaking by lubricating the skin surface. Emollients are divided into:

• Protective emollients: diisopropyl dilinoleate and isopropyl isostearate.
• Astringent emollients: dimethicone, cyclomethicone.
• Fatting emollients: castor oil, propylene glycol, octyl stearate, glyceryl stearate, jojoba oil.
• Drying emollients: isopropyl palmitate, decyl oleate, isostearyl alcohol.

Moisturizer is larger from definition and is better suited as a general term for moisturizing and emollient skin products. Emollients mostly imply smoothing out dry skin keratin to leave the skin soft and moisturized without dryness. Most commonly, moisturizing and emollient skincare products are described as moisturizers as a broad term, and emollients as a class of moisturizers.

Notably, when you read the literature about "atopic dermatitis", the word "emollient" is used more as a general term for moisturizing and emollient products. It is because emollients are all about reducing dryness, and dry skin is the primary and most critical clinical sign of "atopic dermatitis".