Issue link: https://www.ascpskindeepdigital.com/i/1507658
62 ASCP Skin Deep Autumn 2023 Essentially, all retinols are retinoids but not all retinoids are retinols. Other types of retinoids used in skin care include adapalene and tretinoin, both of which often require a doctor's prescription due to their higher potency. Of course, aging naturally is a perfectly valid choice, and no one should feel pressure to reverse or slow the signs of skin aging. But if someone is looking to do so, retinol is a great place to start. RETINOL: A BRIEF HISTORY While the ingredient has become ubiquitous in modern skin care, uses for retinol vary and date back to ancient Egypt, when livers (which are rich in vitamin A) were used to treat endemic night blindness. This makes sense when you consider that other vitamin A-rich foods, like carrots, are commonly thought to improve eye health. The link between retinol and skin health was rst established during World War I, when it was discovered that a de ciency of retinol in the body can lead to dry skin and follicular hyperkeratosis, or bumps on the skin caused by a keratin buildup at the hair follicles. 1 Retinol in cosmetics became available over the counter in the 1980s, and in the 1990s, studies showed that topical retinol could help thicken the skin 2 and stimulate collagen production, 3 concluding that it's an e ective treatment for skin aging. However, this research also determined that formulation plays a crucial role in the e cacy of retinol, given how unstable of an ingredient it is. 4 In the 2010s, retinol became a highly sought-after skin care ingredient seemingly overnight, which Esau says unfortunately led to its misuse. Because consumers weren't properly informed about how potency levels a ect the skin or how to choose a formulation that works for them, many retinol users falsely believed that it was too irritating for their skin. "It went through this phase, maybe 8–10 years ago, where it was kind of put back under the radar of, 'No, we don't want to use it on our skin, it's creating sensitivities,' and now it's coming back around," Esau says. "So many people would say, 'Oh, no, that irritates the skin,' and we realized that there was a misunderstanding and [we needed] to educate again." WHAT CAUSES SKIN AGING? To better understand how retinol ts into skin care, it's necessary to rst understand what exactly goes on during the skin's aging process. While there are several factors involved in the skin's aging process (including genetics, environment, and hormones), the one that has the most impact on skin aging is ultraviolet (UV) exposure. 5 "The skin, being the ultimate protective barrier between the internal organs and the environment, is exposed to UV irradiation and, to a lesser extent, other DNA-damaging agents such as cigarette smoke, automobile exhaust, and professional exposure," notes a 2006 study published in the medical journal Clinical Interventions in Aging. 6 In addition to exposure to free radicals, the body's production of collagen (which is responsible for plump and youthful-looking skin) naturally slows over time, resulting in dullness, wrinkles, and loss of elasticity. Falling estrogen levels in women also have an impact on skin's appearance and can result in premature skin aging. 7 RETINOL'S ROLE IN SKIN CARE Retinol has proven e ective for aging skin because it plays an active—and very important—role in your body's collagen production. "Vitamin A is a nutrient that synthesizes with your cells to create more collagen and elastin to be used as needed," Esau says. Other ingredients with similar claims, like peptides, are not nearly as e ective as retinol simply because they don't function in the same way. "Peptides are signaling for collagen and elastin to be synthesized, but they're not building it," Esau says. "Peptides and vitamin A can be used together, but you've got to have the nutrients there for the cell to even be signaled. Sometimes, it can be signaled to do something, but it's almost spinning its wheels . . . you're telling it to work with this peptide, but it has no resources to really synthesize." WHY FORMULATION MATTERS Common complaints from retinol users include sensitivity, in ammation, and other negative skin reactions. However, Esau says in many of these cases retinol itself likely isn't the culprit. Usually, one of two things is happening: either the strength of the retinol is too potent for the individual's skin type, or the retinol is formulated with exfoliating or otherwise irritating ingredients. "A lot of vitamin A is formulated with other types of acids, [such as] salicylic acid or lactic acid, and with that, you're getting exfoliation with the skin," Esau says. "For years, those were the main types of vitamin A that were recommended across the board to the masses. [Consumers] would either get a prescription or they would get a vitamin A with some kind of acid in it. So, the vitamin A ingredient itself kind of got a bad rap, but it really wasn't that, it was [the other ingredients it was] formulated with and how it was used."