Transform Your Skin with Retinoids

The Miracle Ingredient for Flawless Skin

Retinoids are liposoluble compounds derived from vitamin A and are classified as either therapeutics or cosmeceuticals*, natural or synthetic (Table 1.) (1, 2). Dermatologists have prescribed tretinoin, isotretinoin, adapalene and other retinoid-like drugs for topical and oral treatment of various skin conditions, including acne vulgaris, rosacea, psoriasis, ichthyosis, etc (3, 4). However, other retinoids like retinol and its esters, along with retinaldehyde, can be found in cosmetic products (2). Topical application of these compounds results in their molecular activity by penetrating the skin barrier and diffusing through plasma membranes. The subsequent binding with a cellular retinoic acid binding protein and then nucleus receptors induces modulation in the expression of genes responsible for cellular differentiation and proliferation (1).

Table 1. Retinoids can be classified as natural or synthetic compounds. Therapeutic drugs have been italicized (2).

Benefits of cosmeceutical retinoids:

  • Antioxidant: in vitro studies have demonstrated that retinoids scavenge free radicals. To optimize its antioxidant properties, it is recommended to use it in combination with other topical antioxidants (1).
  • Depigmenting effect: retinoids regulate the function of melanocytes by arranging melanin in the epidermis, blocking its transport to epidermal cells, and reducing the stimulated melanocytes activity (4).
  • Anti-aging agent and photoaged skin improvement: retinoids inhibit collagen from degradation, improve skin elasticity, suppress the activity of metalloproteinases, and promote angiogenesis in the papillary layer of the dermis (4).
  • Improvement of skin texture: the development of the keratin layer through increased production of epidermal proteins and keratinization results in smoother and more uniform-looking skin (4).
  • Suitable for acne-prone skin: the anti-comedogenic effects of retinoids allow them to regulate the shedding process in sebaceous gland ducts (4). Also, they decrease sebum secretion, thereby reducing blackhead formation (5).
  • Reduction of dryness: retinoids reduce transepidermal water loss (4).

*While the term “cosmeceutical” for consumers refers to a product that can significantly enhance the appearance and health of the skin, it is essential to note that from a regulatory perspective, cosmeceuticals are classified only as cosmetics and do not require a prescription (6).

Navigating the Side Effects of Retinoids

Skin irritation, desquamation, and redness are the most frequently observed adverse reactions associated with topical retinoids (3). The potency of retinoid-like activity after topical application is ranked the highest for retinoic acid, followed by retinaldehyde, retinol and retinyl esters (Figure 1.) (1).

Figure 1. The activity of retinoid compounds: retinoic acid > retinaldehyde > retinol >> retinyl esters. The arrow represents the direction of metabolic pathways after the application of retinoids on the skin (1).

The metabolic pathways in the skin involve the hydrolyzation of retinyl esters into retinol, which is then oxidized into retinaldehyde, and finally, oxidized to retinoic acid. Therefore, ester forms are the less irritant retinoic components (Figure 1.) (1).

When using topical retinoids for the first time, it is advisable to introduce them slowly (Figure 2.). To enhance tolerability, the use of barrier repair moisturizers is recommendable. Also, individuals who have used hydroxy acids in topical products for prolonged periods before commencing retinoid treatment may experience reduced irritation from retinoids (3).

Figure 2. Guidelines for initiating the use of retinoids (3).

Is it safe to use retinoids during the daytime? 

Topical retinoids are recommended for nighttime use not because of photosensitivity or phototoxicity but due to their poor stability (3). An animal-based in vitro study has demonstrated the effectiveness of retinoic acid, retinaldehyde, retinol, and retinyl palmitate in preventing DNA photo-damage and UVB-induced apoptosis (7). They strongly absorb UV light because of the double bonds in the structure. However, when exposed to UV light, retinol or its esters produce free radicals and reactive oxygen species that can harm various cellular components such as proteins, lipids, and DNA. The balance between the beneficial filtering properties and the potential harm to biomolecules depends on multiple factors. Therefore, it is advisable to avoid exposure to UV radiation while using topical retinoids (1).

Get Your Glow On: Vitamin A Derivatives for Radiant Skin

The following section will analyze two types of retinoid ingredients and their advantages in the cosmetic industry.

Retinol night serum

Due to its instability while exposed to sun and air, retinol rapidly degrades into biologically inactive forms. To maintain its potency and prevent oxidation, it is crucial to properly manufacture, formulate, and package retinol (3). In the chosen product, the protective capsules shield the compound, ensuring its effectiveness.

In order to become active within the epidermis, retinol is transformed into all-trans retinoic acid, aka tretinoin, through a specialized metabolic process within the keratinocytes. When compared, retinol is approximately 20 times less potent than the prescribed drug tretinoin (3).

The claims “reduce lines and wrinkles “, “the skin is more hydrated” and  “visibly firmer skin” are closely linked to the benefits of retinoids mentioned at the beginning of the article.

Retinal serum with HA 

This product contains 0.11% of retinaldehyde, also known as retinal. Unlike retinol, it can be oxidized very rapidly to retinoic acid (1).

It is the most potent retinoid utilized for cosmetic purposes. Studies have found that combining the topical application of intermediate-size hyaluronic acid fragments with retinaldehyde can result in epidermal hyperplasia and increase hyaluronic acid content within the epidermis and dermis (8).

The “Retinoids without the harshness” claim is correct. Retinaldehyde does not bind to nuclear retinoid receptors. Instead, it selectively provides low concentrations of retinoic acid on a cellular level which helps prevent an overabundance of retinoic acid in the skin that contributes to cutaneous irritation (1). Also, other shooting ingredients used in the formula, such as ceramides, squalene, and bisabolol, may reduce skin irritation.

The claim of possessing the “antibacterial effect” is accurate. Retinaldehyde has a unique aldehyde functional group that enables direct receptor-independent biological effects not observed in other retinoids. This quality highlights the efficacy of at least 0.05% topical retinaldehyde in combating P. acnes and Staphylococcus spp (9,10).

“Reduce photoaged appearance” and “improve uneven tone” claims are already mentioned in the benefits of cosmeceutical retinoids.

References:

  1. Draelos ZD. Cosmetic Dermatology: Products and Procedures. 1st ed. UK: Blackwell Publishing Ltd; 2010. 532 p.
  2. Babamiri K, Nassab R. Cosmeceuticals: The Evidence Behind the Retinoids. Aesthetic Surgery Journal. 2010 Jan 1;30(1):74–7.
  3. Baumann L. Cosmetic dermatology and medicine: principles and practice. 2nd ed. New York: McGraw-Hill; 2009. 366 p.
  4. Zasada M, Budzisz E. Retinoids: active molecules influencing skin structure formation in cosmetic and dermatological treatments. pdia. 2019;36(4):392–7.
  5. Aldag C, Nogueira Teixeira D, Leventhal PS. Skin rejuvenation using cosmetic products containing growth factors, cytokines, and matrikines: a review of the literature. Clin
  6. Draelos ZD. Cosmeceuticals. Dermatologic Clinics. 2019 Jan;37(1):107–15.
  7. Sorg O, Tran C, Carraux P, Grand D, Hügin A, Didierjean L,et al. ( 2005 ) Spectral properties of topical retinoids prevent DNA damage and apoptosis after acute UVB exposure in hairless mice. Photochem Photobiol 81, 830 – 6.
  8. Cosmet Investig Dermatol 2016; 9: 411-9. Kaya G, Tran C, Sorg O, et al. ( 2006 ) Synergistic effect of retinaldehyde and hyaluronate fragments in skin hyperplasia. J Invest Dermatol 126, 33.
  9. Péchère M, Germanier L, Siegenthaler G, Péchère J, Saurat JH. (2002) The antibacterial activity of topical retinoids: the case of retinaldehyde. Dermatology 205, 153 – 8.
  10. Péchère M, Péchère JC, Siegenthaler G, Germanier L, Saurat JH. (1999) Antibacterial activity of retinaldehyde against Propionibacterium acnes. Dermatology 199 (Suppl 1), 29 – 31.