Retinol, which is Vitamin A, and topical derivatives of Vitamin A have found wide applicability in aesthetics. Vitamin A and its derivatives have benefits for skin and are used in several iS Clinical products.
THE VARIOUS VITAMIN A COMPOUNDS
Retinol is Vitamin A, although the naming convention in aesthetics has been to refer to a derivative (compound chemically related to or derived from) of Vitamin A as “a retinol,” although in the strict chemical sense, this is somewhat of a misnomer. These include the non-pharmaceutical derivatives, such as retinyl palmitate and others, and the pharmaceuticals, such as tretinoin (Retin-A) and others, although this colloquialism is probably most used when referring to tretinoin (Retin-A). Strictly speaking and for clarity, tretinoin (Retin-A) should be referred to by its own chemical name, tretinoin (Retin-A). The term “retinoid” refers to all molecules that are similar to retinol and which are derived from retinol and within the same chemical grouping.
Also chemically speaking, retinol is an alcohol. Retinoic acid is an acid. Retinaldehyde, or retinal, is an aldehyde. Retinyl palmitate, retinyl acetate, and retinyl propionate are esters. Although each of these may be individually described in these ways according to specific molecular structure, they are all part of the retinoid family of molecules and, as such, are chemically related to but not identical with retinol. These may be chosen for inclusion within topicals according to their combining ability with other specific ingredients in the end product and their individual formulation characteristics within that product.
RETINOIDS IN iS CLINICAL PRODUCTS
Retinol is used in several iS Clinical products – Pro-Heal Serum Advance+, Poly-Vitamin Serum, Intensive Resurfacing Masque, Active Peel System, and the Prodigy Peel Systems.
Retinyl palmitate is an ingredient in Body Complex, Cleansing Complex, Eye Complex, Moisturizing Complex, Reparative Moisture Emulsion, SHEALD Recovery Balm, Youth Complex, Youth Eye Complex, Youth Intensive Crème, Youth Serum, and the Foaming Enzyme Masque System.
In all these products, except the Prodigy Peel Systems, the ingredients are designed to be non-keratolytic. As such, they are not associated with peeling, flaking, or irritation. The Prodigy Peel Systems, however, are designed to be keratolytic and often induce peeling and/or flaking. In the Prodigy Peel Systems, the retinol is formulated in such a way and combined with the other ingredients within the formula to behave as a chemical peel.
NON-ANIMAL SOURCES
iS Clinical products containing retinol and its derivatives are never derived from animal sources. Although animal liver is an abundant and ready source of Vitamin A and may be labeled “natural,” all iS Clinical retinols are vegetal.
iS CLINICAL PRODUCTS CONTAINING RETINOL OR RETINOIDS IN PREGNANCY Obstetricians often advise discontinuing any form of oral retinol use during pregnancy and may also cautiously include topicals in this recommendation. During pregnancy, excessive amounts of Vitamin A or derivatives taken internally could be teratogenic. Except for the Prodigy Peel Systems, iS Clinical products containing Vitamin A or its derivatives are safe and may be used during pregnancy.’ The iS Clinical retail cosmeceuticals are non-systemic and do not deliver their ingredients to the bloodstream. This means they do not travel throughout the body to various organ systems.
USES OF VITAMIN A IN THE SKIN
Within the skin cell, retinoids are all converted to the same active molecule, retinoic acid.2 Even isotretinoin (Accutane) may act as a pro-drug acting as an agonist at the retinoic acid receptor in the cell nucleus.3
Retinol is required for healthy growth, development, and maturation of all epithelial tissues in the body – and skin is an epithelial tissue. The actions of Vitamin A and its cellular metabolite, all-trans retinoic acid, in skin include:45 67
- Normal epithelial growth and differentiation
- Skin barrier functionality
- Collagen synthesis
- Wound healing, all stages
- Antioxidant activity
- Anti-inflammatory activity
- Anti-aging effects
ACTIONS, PREPARATIONS, AND SIDE EFFECTS
All topical retinoids share common activations on many nuclear receptors, including RAR (retinoic acid receptor) and RXR (retinoid X receptor), thus accounting for their similarities in functionality and toxicity. They regulate epithelial cell growth and proliferation via receptor activities and intercellular communications. Topical retinoids have similar potential side effect profiles that are concentration and dose dependent.
The ‘retinoid reaction” is a description of the most frequent and common adverse reaction seen with these compounds. It is an irritative response with pruritis, burning, itching, peeling, or flaking, and erythema. This reaction is related to the release of pro-inflammatory cytokines during the first weeks of use. It may relate to a relative deficiency in retinol within the skin and may be countered by gradually increasing topical use of the preparation.
Photosensitization can occur at the beginning of topical retinoid therapy but fatigues after a few months. Sunscreen use and sun avoidance are advised at the initiation of use of products containing the Vitamin A group of molecules. If any exfoliating product is used, sunscreen should always be used consistently.
When compared in topical preparations, retinol is associated with considerably fewer side effects of irritation, erythema, and dermatitis than retinoic acid.10
Topical retinoids can be manufactured in cream, gel, and liquid forms.
The pharmaceutical retinoids – tretinoin, isotretinoin, and others are not manufactured by iS Clinical and a discussion of them is not included herein.
REFERENCES
11Nokynek GJ et. al. Repeated topical treatment, in contrast to single oral dose, with Vitamin A-containing preparations does not affect plasma concentrations of retinol, retinyl esters, or retinoic acids in female subjects of child-bearing age. Toxicol Lett. 2006 May 5. 163(1): 65-76.
2Zasada M, Budzisz E. Retinoids: active molecules influencing skin structure formation in cosmetic and dermatologic treatments. Postepy Dermatol Alergol. 2019 Aug. 36(4): 392-397.
3Layton A. The use of isotretinoin in acne. Dermatoendocrinol.
2009 May-Jun. 1(3): 162-169.
*Fisher GJ, Voorhees JJ. Molecular mechanisms of retinoid
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“Kong R, Cui Y, Fisher GJ, Wang X, Chen Y, Schneider LM, Majmudar G. A comparative study of the effects of retinol and retinoic acid on histological, molecular, and clinical properties of human skin. J Cosmet Dermatol. 2016 Mar. 15(1): 49-57.
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“Palace VP, Khaper N, Qin Q, Singal PK. Antioxidant potentials of Vitamin A and carotenoids and their relevance to heart disease. Free Radic Biol Med. 1999 Mar. 26(5-6): 746-761.
“Retinoids, topical. www.aocd.org.
“Torras H. Retinoids in aging. Clin Dermatol. 1996. 74: 207-215.
1oKang S, Duell EA, Fisher GJ, et. al. Application of retinol to human skin in vivo induces epidermal hyperplasia and cellular retinoid binding proteins characteristic of retinoic acid but without measurable retinoic acid levels or irritation. 1995. J Investig Dermatol. 105: 549-556.
DISCLOSURES
Paper written by Charlene DeHaven MD, FACEP Clinical Director, Innovative Skincare
Supported by iS Clinical® by Innovative Skincare www.isclinical.com