A good moisturizer is the need of the hour as it helps to prevent dry skin and keep your skin soft and smooth, especially in winters. Moreover, it also improves skin hydration and helps you to deal with dermatitis. However, choosing the right moisturizer is a challenge because of the numerous varieties of moisturizers available in the market. So to pick a good moisturizer for your skin, here are a few things you must be aware of!
Moisturizers: Types And What It Means?
Moisturizers can be considered as cosmetics as well as therapeutic products for conditions such as dry skin. These are designed to either improve the hydration of the skin or restore skin hydration. Based on the components present in a moisturizer, it is broadly classified into four categories: humectants, occlusives, emollients, and natural moisturizing factors.
Humectants: These are substances which attract moisture when applied on the skin and hence, improve hydration of the outermost layer of the skin known as stratum corneum. In some cases, these are also shown to reduce abnormal thickening of the skin and appearance of scaling seen in people with extremely dry skin (xerosis) and ichthyosis.
However, humectants are a double-edged weapon as they increase transepidermal water loss (loss of water from the skin layers) by enhancing water absorption from the dermis into the epidermis where it is easily lost to the environment. This is the reason these are mostly used along with other types of moisturizers to retain moisture. The common examples of humectants include glycerin, sorbitol, urea, alpha hydroxy acids, and sugar.
Occlusives: Occlusives block transepidermal water loss in the stratum corneum and help to maintain water content. It has the most significant effect when applied to moistened skin by creating a hydrophobic barrier over the skin. Occlusives diffuse into the intracellular structures, thus enhancing its efficacy.
Petrolatum is the most effective classic occlusive moisturizer as it can reduce trans-epidermal water loss by more than 98%. Lanolin, mineral oil and silicones (eg, dimethicone) can reduce trans-epidermal water loss by 20% to 30%. The factors which make occlusives less acceptable is its unpleasant odor, potential allergic reactions, and greasy consistency.
Emollients: These are long chain saturated fatty acids (stearic, linoleic, oleic, lauric acid and fatty alcohols) which are commonly used in cosmetic formulations or topical applications. When incorporated into moisturizers, it helps to soften the skin through the filling of spaces between the skin cells. Moreover, it can act as a barrier to water loss when applied heavily on the skin.
Typical emollients used in moisturizers include squalene, cholesterols, and fatty acids, which are found naturally in wool fat, palm oil, and coconut oil. These are commonly used for people with sensitive skin. However, for those with oily skin, oil-free emollient products are also available which contain glycol or glycerin. However, these compounds can cause extreme dryness and stinging sensation when applied to sensitive skin.
Natural moisturizing factors: These are named based on the similar compounds found in the epidermis which play a key role in maintaining the skin hydration. These factors contain a combination of naturally occurring free amino acids, urocanic acid, inorganic salts, sugars, lactic acid, and urea. The natural moisturizing factors are highly effective in absorbing and binding water from the atmosphere and ensuring proper hydration of the skin cells even in low humid environments.
The efficacy of moisturizers depends largely on proper selection and compliance to continuously use it. Commercially available moisturizers often utilize components of each of these classes to provide their beneficial effect.
(The article is reviewed by Dr. Lalit Kanodia, General Physician)
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