Moisturizer: What It Is, Uses and tips 

Moisturizers are categorized based on their functionalities, which encompass inhibiting water loss from the skin, augmenting the skin's water content, and diminishing visible flaking. Recent advancements in understanding the structure and function of the skin barrier have notably progressed the science behind moisturizer formulation. Consequently, contemporary moisturizers often integrate ingredients with varied mechanisms of action to attain designated outcomes. [1.1] 

Moisturizer: structure and ingredients 

The skin is a multifaceted organ composed of several layers; its architecture is structured to reduce moisture depletion from the body and simultaneously act as a barrier against external contaminants. Achieving these roles necessitates a protective lipid layer. Everyday environmental factors can deplete the skin of these essential lipids; hence, moisturizers with oil-soluble elements are frequently utilized to reinstate the skin's inherent state. Most moisturizers employ a blend of both oil and water-soluble constituents, known as an emulsion [3.1]. 

Moisturizers play a pivotal role in skincare, combining diverse ingredients to hydrate and protect the skin. Below is an overview of the key components commonly found in these formulations and their respective functions. 

Water 

Most moisturizers consist of oil-in-water emulsions, categorizing them as creams and lotions. The primary ingredient is often water, which partly evaporates upon application, with the remainder being absorbed by the stratum corneum. However, to retain this moisture, an oily substance is essential. Merely applying an oil-based product without water replenishment can result in unhydrated yet oily skin. The optimal approach for skin hydration is initial water immersion followed by an oil-based application, but for convenience, moisturizers containing water are generally preferred. [2.2] 

Occlusives 

Substances like petrolatum function as occlusives by preventing water evaporation. While there are numerous occlusive agents, petrolatum remains predominant. Other notable occlusives are cetyl alcohol, lanolin, lecithin, mineral oil, paraffin, stearic acid, dimethicone, and cyclomethicone. Products labeled as 'oil-free' typically rely on dimethicone. The efficiency of occlusives differs, with petrolatum being the most effective. [2.3] 

Humectants 

These are designed to draw water into the stratum corneum from ambient air and deeper skin layers. In low-humidity conditions, the primary moisture source is internal. Prominent humectants encompass glycerin, honey, panthenol, sorbitol, and urea. However, for effectiveness, they're typically combined with occlusives to seal the moisture they attract. [2.4] 

Emollients 

While not primary moisturizers, emollients are incorporated to enhance skin smoothness. Many occlusives and humectants, such as dimethicone, also function as emollients. Contrary to the drying nature of certain alcohols, some, like octyl dodecanol, serve as effective emollients. [2.5] 

Vitamins 

While retinoic acid, a form of vitamin A, is known for collagen stimulation and wrinkle reduction, some moisturizers utilize retinyl palmitate, a less active variant. Vitamin C (ascorbic acid) and vitamin E (tocopheryl acetate) are integrated due to their antioxidant properties. Conversely, tocopheryl acetate primarily acts as a preservative. [2.6] 

Differences between different kinds of moisturizers 

In the realm of skincare and moisturization, there exists a spectrum of product types primarily categorized as ointments, creams, lotions, and gels. Each type possesses a unique composition characterized by varying ratios of oil and water, which inherently influences its texture and functional applicability. 

The selection amongst these formulations is consequential, often dictated by the specific skincare concern one intends to address. A singular product type may not universally suffice for varied skincare necessities, underscoring the need for discernment in choice. 

Additionally, the intrinsic texture of these products, ranging from lighter to heavier consistencies, necessitates consideration of one’s individual skin type to ensure compatibility and effectiveness. [4.1] 

Ointment 

A preparation with an oil base that is designed for topical application to the skin is termed an ointment. Contrarily, a cream is distinguished by its water-soluble composition [5]. 

Cream 

A medicinal formulation for topical application to the skin is characterized by its water solubility. In contrast, an ointment is oil-based, distinguishing it from the water-soluble nature of a cream. [6] 

Lotion 

Lotions predominantly consist of water, supplemented by oil and occasionally alcohol. For individuals with combination, oily, or acne-prone skin, oil-free lotions may be preferable [4.2]. 

Gel 

Gel formulations usually comprise cellulose, water, and alcohol. There are also hybrid gel-lotion products available that apply similarly to lotions. [4.3] 

Moisturizers: how to use and tips 

For optimal skin hydration, it's essential to select appropriate products for distinct facial and body requirements. While certain age or conditions, such as acne, might necessitate specialized products, the following guidelines can be consulted for moisturizer selection [7.1]: 

• Normal skin typically benefits from water-based moisturizers with a lightweight, non-greasy consistency. 
• Dry skin requires more substantial, oil- or petrolatum-based formulations that are designed for moisture retention. 
• Oily skin is best treated with water-based, non-comedogenic formulations. 
• Sensitive skin can benefit from water-based formulations containing calming ingredients like aloe, chamomile, or calendula. 
• Mature skin tends to respond favorably to oil- or petrolatum-based moisturizers. 

For effective moisturization, it is advisable to apply skin-specific moisturizers to the face and body within ten minutes of bathing or showering. This practice assists in sealing in moisture, reducing the necessity for frequent reapplication. [7.2] 
 

References 

1. Moisturizers [StatPearls, Internet, 2022] URL: https://www.ncbi.nlm.nih.gov/books/NBK545171/ - 1 , 2 , 3 , 4, 5 
2. Moisturizers: how do they work [Harvard Health] URL: https://www.health.harvard.edu/staying-healthy/moisturizers-do-they-work - 1 , 2 , 3 , 4 , 5 
3. The Chemistry Behind Moisturizers [Illumin USC Viterbi, 2003] URL: https://illumin.usc.edu/the-chemistry-behind-moisturizers/ - 1 
4. What’s the Difference Between Ointment, Cream, Lotion, and Gel? [Healthline, 2022] URL: https://www.healthline.com/health/ointment-vs-cream - 1 , 2 , 3 
5. Definition of ointment [RXList] URL: https://www.rxlist.com/ointment/definition.htm 
6. Definition of cream [RXList] URL: https://www.rxlist.com/cream/definition.htm 
7. Moisturize your body [Wiki How] URL: https://www.wikihow.life/Moisturize-Your-Body - 1 , 2 
8. How to moisturize your skin [Harvard Health] URL: https://www.health.harvard.edu/staying-healthy/how-to-moisturize-your-skin - 1