Type of Ingredient: Vitamin A derivative, and antioxidant and increases cell turnover
Main Benefits: Improve signs of aging, hyperpigmentation, and acne.
Who Should Use It: Used in low concentrations to address signs of aging. Those who suffer from acne and hyperpigmentation problems may use higher concentration, under supervision of a doctor. Those who are planning to get pregnant, pregnant or nursing should not use retinol or any form of retinoids.
Ideal For These Concerns: Acne, wrinkles, fine lines, sun damage, and scars.
How Often Can You Use It: You can use it at night.
What is Retinol?
As a class, retinol is well-known to address the signs of aging and improve acne symptoms when applied topically. Retinol is an ingredient in the retinoid family. Retinoids are derivatives of Vitamin A. The retinoid family consists of retinol, retinaldehyde, and retinoic acid, as well as a large number of synthetic derivatives. The first retinoid, tretinoin (retinoic acid) was developed three decades ago, initially used for the treatment of acne. While retinoic acid is available as a topical prescription treatment (tretinoin, brand name Retin-A), it often causes skin irritation burning, scaling, dermatitis and photosensitivity. Now, however, several important derivatives of vitamin A are used by dermatologists. These include isotretinoin and acitretin. It was found that these drugs affect cell differentiation.
It is important to note that not all retinol is created equal. Over the counter skin care products claiming to contain retinol may not necessarily offer the benefits due to how it was formulated. Factors such as molecular weight, concentration, and storage during the supply chain matters in preserving the active ingredients’ potency.
The Benefits of Retinol
Retinol exfoliates the skin by causing more rapid shedding of the stratum corneum. The stratum corneum is typically composed of 14 layers of densely packed corneocytes (dead skin cells). The use of topical retinol sloughs off several of these cell layers, thinning the stratum corneum to eight or nine layers of more loosely woven skin cells. The combination of rapid regeneration of cells and exfoliation of the stratum corneum not only improves the appearance of aging skin but also helps to peel away dark spots and blemishes. Over time these actions improve acne, soften the skin, lift dark spots and reduce the appearance of wrinkles.
Tretinoin has proved to be extremely effective in the treatment of acne vulgaris. In the United States, it is commercially available as a gel, cream, or liquid. Typical side effects of topical retinoid use are dryness, irritation, and possibly photosensitivity at the site of treatment. According to research conducted by Bhawan and colleagues, tretinoin requires at least six months to appreciable improve the dermal level. Meaning, retinol and retinoids usually require usage of at least 6 months before improvements in the skin can be observed. It is important to note that amongst retinoids, tretinoin is the most potent and best-studied retinoid. However, its irritation potential has prompted dermatologists to switch over to less irritating but comparably effective retinoids like adapalene and to some extent retinol and retinaldehyde.
Lastly, retinol functions as an antioxidant to limit oxidative damage caused by free radicals. Free radicals are derived from both internal sources (i.e. peroxisomes, phagocytic cells, etc.) and external sources (UV radiation, pollution, alcohol, tobacco smoke, heavy metals, pesticides, etc.) Free radicals are dangerous because they are highly reactive molecules and can damage important cellular structures, like DNA, proteins, carbohydrates, or the cell membrane. Altogether, the damage to cells caused by free radicals is known as oxidative stress. The free radical theory of aging (FRTA) states that organisms age because cells accumulate oxidative stress caused by free radical damage over time.
Topical retinoids can irritate the skin, especially when first used. It is recommended that users ease into usage of retinols with a frequency of application once a week, then increasing the frequency over time to give the skin time to adapt. Excessive use results in redness, swelling, peeling and blistering in treated areas. It may cause or aggravate eczema, particularly atopic dermatitis. By peeling off the top layer of skin, retinoids may increase the chance of sunburn. Therefore, it is critical that consistent use of sunscreen is important when retinoids are used. Irritation may also be aggravated by exposure to wind or cold, use of soaps and cleansers, astringents, peeling agents and certain cosmetics.
The United States Food and Drug Administration has approved the use of retinyl palmitate for several over-the-counter (OTC) products. The safety of topical retinoids (including retinyl palmitate) has been assessed on several occasions by the Cosmetic Ingredient Review (CIR) Expert Panel. However, clinical studies have shown that oral retinoid, mainly isotretinoin, cause birth defects when taking during pregnancy. Hence, retinoids come with a warning for those who plan to get pregnant, currently pregnant, or nursing to not use oral or topical retinoids to avoid complications.
According to European Medical Agency (EMA) updated review on retinoids published in 2018, added a new warning that use of oral retinoids may be linked to neuropsychiatric disorders (such as depression, anxiety and mood changes).
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Dermatoendocrinology, July 2012, issue 3, pages 308-319
Toxicological Research, March 2010, pages 61-66
Archives of Dermatology, May 2007, pages 606-612
The Journal of Pathology, January 2007, issue 2, pages 241-251
Clinical Interventions in Aging, December 2006, pages 327-348
Bhawan J, Olsen E, Lufrano L, et al. Histologic evaluation of the long-term effects of tretinoin on photodamaged skin. J Dermatol Sci. 1996;11:177–82.