If you have ever wondered if your expensive creams and serums actually work, listen to this podcast to get a better understanding of the science behind the claims your favourite skincare brands are making.
EPISODE DESCRIPTION
When it comes to keeping our skin looking younger, what works? Retinol, hyaluronic acid, vitamin C? This simple question has become confused by the billion-dollar skin-care industry, which floods us with scientific-sounding claims about the chemicals they say we should put on our face. We find out the real science on what you need for healthy skin with Dr Natalia Spierings, Dr Szu Wong and Kirsten Drysdale.
In the beauty industry, cosmetic ingredients are presumed safe and effective until proven otherwise. Manufacturers are not required to demonstrate the efficacy or safety of ingredients in their specific formulations and concentrations. Often, the only way to determine if a cosmetic product works is through personal trial. For this reason, to save time and expense, I am turning to science to find out if some of the most heralded ingredients in our favourite skincare products, such as peptides, Vitamin C, collagen, hyaluronic acid, and even retinoids, actually work. I’ll be discussing some of the main points of the podcast as well as my own research into these ingredients to give you a well-rounded overview on the topic.
According to Science Vs, products containing Vitamin C are often ineffective due to two key factors. First, Vitamin C molecules are water-soluble, but to penetrate the stratum corneum (the outermost layer of skin), they need to be fat-soluble. Second, Vitamin C is highly unstable—it breaks down when exposed to light and oxidises when exposed to air, such as when we use our droppers to apply the Vitamin C serum. This oxidation causes Vitamin C to lose its antioxidant properties.
The next ingredient discussed is collagen. Unfortunately, collagen molecules are too large to effectively penetrate the skin when applied topically. As a result, claims that topical collagen products can directly replace or boost collagen levels in the skin are unfounded. While some studies suggest that topical collagen may provide moisturising and skin-conditioning benefits, its ability to directly impact skin collagen levels is limited. However, when ingested, collagen peptides (smaller fragments of collagen) may stimulate the body’s natural collagen production, potentially leading to improvements in skin elasticity, hydration, and overall appearance. Nonetheless, further research is needed to fully understand the benefits and efficacy of ingested collagen peptides.
Another ingredient that falls short is Hyaluronic Acid (HA), the humectant (water-attracting) component found in serums, moisturisers, sheet masks, night creams, and lip products widely believed to bind to 1000 times its weight in water. New research has discredited this claim, which has been cited for decades. Moreover, HA exists in different molecular sizes, and this affects its efficacy. Larger HA molecules, while excellent at binding water, cannot penetrate the skin. When applied topically, these larger molecules remain on the surface, providing hydration only to the outermost layer. Conversely, smaller HA molecules can penetrate deeper into the epidermis (the topmost layer of skin), but they bind less water than their larger counterparts. As a result, while smaller HA molecules may contribute to skin hydration, they are ineffective as an anti-wrinkle treatment. Interestingly, injecting HA as a dermal filler is considered the most effective way to combat wrinkles, according to scientific evidence. This method delivers HA directly into the deeper layers of the skin, where it can have a more significant impact on reducing the appearance of wrinkles—not ideal if you were hoping for topical ways to fight the signs of ageing.
“…it’s hard to accept the fact that a lot of the creams we’re putting on our face don’t really do anything, and that if you’re not up for going under the knife or needles, we’re kind of stuck with our wrinkles.”
Some evidence suggests that retinoids, particularly tretinoin, are among the most promising agents available for treating aging. However, their use is limited by potential irritation and a lack of large, randomized controlled clinical trials. Additionally, retinoids like retinol (vitamin A alcohol) are inherently unstable and susceptible to degradation from light and air exposure, which can hamper their efficacy if not properly formulated and delivered. This instability issue is one of the major challenges with using retinol as a topical anti-aging agent, and has motivated the exploration of nanoparticle delivery systems that can encapsulate and protect retinol from degradation.
One popular group of ingredients not discussed in the podcast is peptides. In the article “How Skin Care Became an At-Home Science Experiment,” Tiffany Cukrowski, a dermatologist at the Midwest Center for Dermatology and Cosmetic Surgery, and Dana Sachs, a dermatologist at the University of Michigan, are both skeptical: “Peptides are chains of amino acids, often included in antiaging serums and creams, with the thought that they might stimulate collagen production. ‘But one of the issues with peptides—that I don’t know the answer to—is they tend to be huge molecules that don’t necessarily penetrate into the skin,’” Sachs says. “The peptides are a big scam,” Cukrowski adds.
Back to the podcoast, the speakers suggest that moisturisers work in that they sit on your skin and keep moisture from leaving, also known as water loss. They agree that aside from sunscreen, there is nothing that is essential. And science concurs:
Skin aging is influenced by several factors including genetics, environmental exposure (UV radiation, xenobiotics, and mechanical stress), hormonal changes and metabolic processes (generation of reactive chemical compounds such as activated oxygen species, sugars and aldehydes). All factors together act on the alterations of skin structure, function, and appearance. Yet solar UV radiation unquestionably is the single major factor responsible for skin aging.
Yes, it’s true: overexposure to ultraviolet (UV) radiation from the sun can cause sunburn, premature ageing (wrinkles, fine lines, and age spots), and increase the risk of skin cancer. Products such as sunscreen, acne medication, and moisturiser are known to be uncontroversially effective, so for me, I would add that, alongside sunscreen, a good cleanser and moisturiser are also essential.
“As we get older, skin gets thinner, it gets drier,” Sachs says. “The barrier is not as good as it used to be. Whenever there are breaks in the barrier, that’s when you are more prone to infection, that can lead to inflammation in the skin. Moisturising the skin is really key to keeping it in good shape.”
Environmental factors such as pollution, smoke, harsh weather conditions (cold winds or dry air), and exposure to chemicals* can damage the skin barrier, leading to irritation, inflammation, and accelerated aging. Similarly, chronic stress can trigger hormonal imbalances, increasing oil production, inflammation, and exacerbating skin conditions like acne, eczema, and psoriasis.
On the other hand, a balanced diet rich in antioxidants, vitamins, and minerals from dark leafy greens like spinach and kale may indirectly support skin health and hyaluronic acid production. Maintaining a balanced diet, staying hydrated, managing stress, getting enough sleep are some of the things you can do, alongside using appropriate skincare products such as moisturisers, to keep skin looking its best.
Featured Image: @tkkatherineblo / via Pinterest
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