A moisturizer, or emollient, is a cosmetic preparation used for protecting, moisturizing, and lubricating the skin. These functions are normally performed by
sebum
A sebaceous gland is a microscopic exocrine gland in the skin that opens into a hair follicle to secrete an oily or waxy matter, called sebum, which lubricates the hair and skin of mammals. In humans, sebaceous glands occur in the greatest nu ...
produced by healthy skin. The word "emollient" is derived from the Latin verb ''mollire'', to soften.
Mechanism of action
In the human body, water constantly evaporates from the deeper layers of the skin through an effect known as transepidermal water loss (TEWL). By regulating its water content, human skin naturally maintains a dry, easily shed surface as a barrier against pathogens, dirt, or damage, while protecting itself from drying out and becoming brittle and rigid. The ability to retain moisture depends on the lipid bilayer between the corneocytes.
Moisturizers modify the rate of water loss, with active ingredients of moisturizers falling into one of two categories: occlusives and humectants.
Occlusives form a coating on the surface of the skin, keeping moisture from escaping. The more occlusive the formulation, the greater the effect. Ointments are more occlusive than
aqueous cream Aqueous Cream BP, also known as sorbolene, is a light, hydrocarbon-based emulsion, which is officially registered in the British Pharmacopoeia and categorised by the British National Formulary as a ''non-proprietary emollient preparation''. It is ...
s, which are more occlusive than lotion. Water loss through the skin is normally about 4–8 g/(m²⋅h). A layer of petrolatum applied to normal skin can reduce that loss by 50–75% for several hours. Oils naturally produced by the human body moisturize through this same mechanism.
Humectants absorb water. They can absorb this water from the air and moisturize the skin when the humidity is greater than 70%, but more commonly they draw water from the dermis into the epidermis, making skin dryer. A study published in Skin Research and Technology in 2001 found no link between humectants and moisturizing effect. When used in practical applications, they are almost always combined with occlusives.
Moisturizers often contain water, which acts as a temporary hydration agent as well as a way for the absorption of some components and evaporation of the moisturizer.
Kinds
There are many different types of moisturizers. Petrolatum is one of the most effective moisturizers, although it can be unpopular due to its oily consistency.
Other popular moisturizers are
cetyl alcohol
Cetyl alcohol , also known as hexadecan-1-ol and palmityl alcohol, is a C-16 fatty alcohol with the formula CH3(CH2)15OH. At room temperature, cetyl alcohol takes the form of a waxy white solid or flakes. The name cetyl derives from the whale ...
,
cetearyl alcohol
Cetostearyl alcohol, cetearyl alcohol or cetylstearyl alcohol is a mixture of fatty alcohols, consisting predominantly of cetyl (16 C) and stearyl alcohols (18 C) and is classified as a fatty alcohol. It is used as an emulsion stabilizer, opaci ...
,
cocoa butter
Cocoa butter, also called theobroma oil, is a pale-yellow, edible fat extracted from the cocoa bean. It is used to make chocolate, as well as some ointments, toiletries, and pharmaceuticals. Cocoa butter has a cocoa flavor and aroma. Its melt ...
,
isopropyl myristate
Isopropyl myristate (IPM) is the ester of isopropyl alcohol and myristic acid.
Uses
Isopropyl myristate is a polar emollient and is used in cosmetic and topical pharmaceutical preparations where skin absorption is desired. It is also used as a ...
,
isopropyl palmitate
Isopropyl palmitate is the ester of isopropyl alcohol and palmitic acid. It is an emollient, moisturizer
A moisturizer, or emollient, is a cosmetic preparation used for protecting, moisturizing, and lubricating the skin. These functions are ...
stearyl alcohol
Stearyl alcohol, or 1-octadecanol, is an organic compound classified as a saturated fatty alcohol with the formula CH3(CH2)16CH2OH. It takes the form of white granules or flakes, which are insoluble in water. It has a wide range of uses as an ...
bath oil
Bath salts are water-soluble, pulverized minerals that are added to water to be used for bathing. They are said to improve cleaning, enhance the enjoyment of bathing, and serve as a vehicle for cosmetic agents. Bath salts have been developed wh ...
s, or
soap substitute
Traditionally, soap has been made from animal or plant derived fats and has been used by humans for cleaning purposes for several thousand years. Soap is not harmful to human health but, like any natural or unnatural surfactant, it does have the p ...
s.
Mineral oils and waxes are insensitive to
oxidation
Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or ...
penetration enhancer
Penetration may refer to:
Science and technology
* Passage through a partition or wall by a wire, cable, or other electrically conductive object
* Penetration (firestop), an opening in a wall or floor assembly required to have a fire-resistance r ...
s,
preservative
A preservative is a substance or a chemical that is added to products such as food products, beverages, pharmaceutical drugs, paints, biological samples, cosmetics, wood, and many other products to prevent decomposition by microbial growth or b ...
s, and solvents. Some products are marketed as having anti-wrinkle and skin enhancement effects. Many plant and animal extracts have been claimed to impart skin benefits, with little scientific evidence.
Use
Moisturizers are used for the treatment of certain skin diseases, such as
psoriasis
Psoriasis is a long-lasting, noncontagious autoimmune disease characterized by raised areas of abnormal skin. These areas are red, pink, or purple, dry, itchy, and scaly. Psoriasis varies in severity from small, localized patches to comple ...
Whitfield's ointment Whitfield's ointment is an acidic ointment used for the topical treatment of dermatophytosis, such as athlete's foot. It can have a slight burning effect that goes away after a few minutes. It is named after Arthur Whitfield (1868–1947), a Britis ...
aftershave
Aftershave is a product applied to skin after shaving. Traditionally it is an alcohol-based liquid (splash), but it can be a lotion, gel, or even a paste.
It often contains an antiseptic agent such as denatured alcohol, stearate citrate or ...
Cochrane review
Cochrane (previously known as the Cochrane Collaboration) is a British international charitable organisation formed to organise medical research findings to facilitate evidence-based choices about health interventions involving health professi ...
noted that moisturizers show some beneficial effects in
eczema
Dermatitis is inflammation of the skin, typically characterized by itchiness, redness and a rash. In cases of short duration, there may be small blisters, while in long-term cases the skin may become thickened. The area of skin involved c ...
. The same review did not find evidence that one moisturizer is better than another.
Potential health risks
Over-moisturization
Persistent moisturization to the skin from exposure to water may contribute to an allergic reaction or irritant contact dermatitis, and can result in penetration of foreign objects.
Changes in the skin's normal ecological environment, in or on the skin, can also support the overgrowth of pathological organisms.
Allergens
Moisturizers containing some aromas or food additives may trigger an immune reaction or even cause users to develop new allergies.
There is currently no regulation over use of the term "hypoallergenic", and even pediatric skin products with the label were found to still contain allergens.
Those with
eczema
Dermatitis is inflammation of the skin, typically characterized by itchiness, redness and a rash. In cases of short duration, there may be small blisters, while in long-term cases the skin may become thickened. The area of skin involved c ...
are especially vulnerable to an allergic reaction with lotions and creams, as their compromised skin barrier allows preservatives to bind with and activate immune cells.
The American Academy of Allergy, Asthma, and Immunology released a warning in 2014 that natural lotion containing ingredients commonly found in food (such as goats milk, cow's milk, coconut milk, or oil) may introduce new allergies, and an allergic reaction when those foods are later consumed. A paper published in 2021 by researchers at St. George’s, University of London found that frequent skin moisturization in early life might promote the development of food allergy, even when skin conditions such as eczema are taken into account.
Fire risk
Paraffin based skincare products and contaminated clothing can pose a serious fire hazard. Between 2010 and 2018, paraffin was linked to 50 fire incidents (49 of which were fatal) in the U.K. A West Yorkshire Fire and Rescue Service study found that clothing contaminated with cream containing only 21% paraffin, when set alight, was fully engulfed in flame in 3 seconds. The Medicines and Healthcare products Regulatory Agency (MHRA) released a warning in 2008 about the flammability of paraffin-based products. MHRA recommends that sheets of people using paraffin are changed regularly, and that people refrain from smoking or bringing open flames around patients using paraffin. MHRA also recommends that skin creams containing any paraffin have a flammability warning on the packaging.
Aveeno
Aveeno is an American brand of skin care and hair care products owned by American consumer goods and pharmaceutical company Johnson & Johnson. Aveeno was founded in 1945 by brothers Albert and Sidney Musher, and its first product was their Soothin ...
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Bath & Body Works
Bath & Body Works, LLC. is an American retail store chain that sells soaps, lotions, fragrances, and candles. It was founded in 1990 in New Albany, Ohio and has since expanded across 6 continents. In 1997, it was the largest bath shop chain in ...
Cetaphil
Cetaphil or is a line of skin care products from the Swiss company Galderma, including cleansers, bar soap, cream, lotion, and moisturizers. It was developed in 1947, in Texas, by an American pharmacist. Cetaphil products are available worldwid ...
Eucerin
Eucerin is a trademarked brand of Beiersdorf AG. In addition to body and face care products, Eucerin offers sun protectant and cleansing products.
History
In 1900, Isaac Lifschütz manufactured a non-perishable and sleek ointment base consi ...
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Gold Bond
Gold Bond is a brand of over-the-counter skin care products produced by Chattem of Chattanooga, Tennessee, now a subsidiary of the French pharmaceutical company Sanofi. It is available as both a powder and a topical cream. Gold Bond is used to cur ...
Jergens Jergens is a surname. Notable people with the surname include:
* Adele Jergens (1917–2002), American actress
* Diane Jergens (1935–2018), American film and television actress
See also
*Andrew Jergens Company
is a chemical and cosmetics c ...
Lux
The lux (symbol: lx) is the unit of illuminance, or luminous flux per unit area, in the International System of Units (SI). It is equal to one lumen per square metre. In photometry, this is used as a measure of the intensity, as perceived by ...
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Neutrogena
Neutrogena Corporation, trading as Neutrogena, is an American company that markets skin care, hair care and cosmetics owned by parent company Johnson & Johnson and is headquartered in Los Angeles, California.Nivea
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Olay
Olay, previously Oil of Olay, Oil of Olaz, Oil of Ulan or Oil of Ulay, is an American skin care brand owned by Procter & Gamble. For the 2009 fiscal year, which ended on June 30, Olay accounted for an estimated $2.8 billion of P&G's revenue.
Ear ...
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Sebamed
Sebamed is a German brand name of Sebapharma GmbH & Co. KG, which manufactures medicinal skin care products.
History
Sebamed was established by Heinz Maurer (1921–2016) in 1957. Since 1971, the Sebamed products are exported to over 70 countri ...
Simple Skincare
Simple Skincare is a British brand of soap and skincare products designed for sensitive skin. Simple has been owned by Unilever since 2010.
History
The brand was developed in 1960 by the Albion Group. In the late 1980s the business was acquired by ...
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Suave
Suave is a brand name based in Chicago, Illinois, used by the Unilever company in the United States, Argentina, Brazil, Mexico and Canada. Targeting discount stores, the brand represents more than 100 products including shampoo, lotions, soap ...