The Secret to Maintaining Youthful Skin

Everyone who loves beauty desires to look more youthful and beautiful, with skin that is hydrated, plump, firm, elastic, has fine pores, bright complexion, balanced color, and is free of blemishes, acne, spots, and wrinkles. As a result, many are willing to spend a significant amount on skincare products.

Looking at the flawless faces of celebrities on television, the internet, and billboards, along with the strong promotion by influencers, internet celebrities, and media on platforms like YouTube, Instagram, and Facebook, it's impossible not to be fascinated by the array of premium skincare products. What marketers are promoting isn't just a bottle of skincare product, but also the fantasy of becoming as radiant as the individuals in the advertisements.

So, are you familiar with the active ingredients in the serums and lotions you apply on your face? Can they penetrate the skin to produce their intended effects?

As mentioned earlier, 90% of skin aging damage comes from exposure to sunlight. Therefore, the first thing to do in combating skin aging is to judiciously use effective and safe physical sunscreens to protect your skin. It's essential to avoid the daily harm to ourselves, the environment, and marine ecology from chemical sunscreens. When choosing skincare products, we need to understand the truly effective anti-aging skincare ingredients that have a medical foundation and proven clinical effects.

The structure and needs of the skin have been deeply understood by medical researchers for decades. Ingredients that meet the following three conditions can be considered effective anti-aging skincare ingredients:

1. They can penetrate the stratum corneum (the outermost layer of the skin) and still have sufficient concentrations delivered to the target epidermal layer, with enough duration to produce effects;

Being able to penetrate the skin's first barrier - the stratum corneum - is crucial. The stratum corneum is the body's largest protective barrier that prevents the loss of moisture from the epidermis and blocks foreign substances from entering the body. Many large molecule skincare ingredients are simply applied to the skin surface and cannot penetrate the skin at all. Even if they can penetrate the stratum corneum, there is a question of whether they have sufficient concentration and duration to be effective. Depending on the product, if less than 10% of 100% lotion can enter the skin, the total amount of effective ingredients is relatively small by proportion; if it cannot reach the minimum required concentration (threshold concentration), its effectiveness is also in question.

2. An acknowledged biochemical or pharmacological mechanism of action exists;

For an ingredient to be effective in anti-aging, it must have a known biochemical action in the body that functions at the cellular level - such as inhibiting or promoting a particular enzyme's signaling pathway, improving gene expression, etc. In other words, it has a physiological mechanism that can be understood and acknowledged by medical researchers. Unsurprisingly, many skincare ingredients found in advertisements are primarily marketing-driven, named to attract attention, but their physical mechanisms are often unclear to scientists and medical professionals.

3. There are sufficient published clinical trials supporting their efficacy. Clinical experiments should have a sufficiently large sample size, be peer-reviewed, conducted in a double-blind manner, have a placebo-controlled group, and show statistically significant results

Advertisements often feature clinical trials that primarily show before/after comparison photos or telephone interviews with testers about their usage experiences. These are not sufficient, not objective, and cannot be considered statistically significant. Meaningful medical clinical trials, in addition to meeting the aforementioned statistical conditions, especially in anti-aging experiments, need to analyze values like transepidermal water loss, corneometry (surface moisture), skin elasticity tests, colorimetry (color analysis), surface replica analysis, and even histology (tissue slice analysis). In this age, can we still simply trust before-and-after comparison photos or user experiences provided by brand-sponsored products?

Ingredients that meet all three of the aforementioned conditions and are widely recognized by medical researchers around the world as effective anti-aging elements are not many. The most commonly accepted ones, supported by medical theory and decades of clinical research, include Topical Retinoids - external application of Vitamin A ointments/creams (requires a doctor's prescription) Topical Retinoids 外塗維他命A類藥膏/乳霜 (需醫生處方)

Since the 1940s, Vitamin A or its derivatives (Retinoids) have been widely used in various skin conditions (most familiarly in the treatment of acne). By the 1980s, Retinoids were applied to skin anti-aging (rejuvenating skin aging), treating skin problems due to intrinsic/chronological aging or premature aging due to sun exposure (extrinsic/photodamaged aging). Retinoids have many natural or synthetic derivatives and can be roughly classified into first to fourth generations. The first to fourth generations do not necessarily mean that the fourth generation is superior; the distinction lies in the different compositions and operations of the derivatives.

Retinoids can improve collaboration at multiple cellular levels, reversing skin aging, including:

  • Promoting skin epidermal cell growth/differentiation/metabolic renewal
  • Improving the keratinization process, accelerating keratin shedding
  • Promoting the generation and accumulation of new collagen and elastin cells in the dermis
  • Increasing glycosaminoglycans/hyaluronic acid in the dermis, enhancing skin's moisture retention capability
  • Promoting dermal blood circulation, supplying/delivering nutrients
  • Gradually reducing wrinkles, improving skin roughness, improving pigment patches, improving sagging
  • Improving the condition of fragile/thin skin
  • Improving wound healing conditions on the skin
  • Expelling excess sebum/reducing excess oil
  • Reducing inflammation responses

The above clinical manifestations have been published in numerous statistically significant studies in medical literature, with clinical research follow-ups ranging from 3 to 24 months, each involving dozens to hundreds of participants. It's not just about before and after photo comparisons; there are also extensive histological examinations of skin tissue. The significant effects also inspire more scholars to join the research on the effectiveness of Retinoids. To date, specific doses of Retinoids are among the few ingredients recognized by the US FDA as significantly effective in treating photoaging.

The actual application effectiveness and significant anti-aging effects of Retinoids are closely related to their formulation, concentration, and method of use. Since Retinoids may cause mild skin reactions, including dryness, redness, peeling, etc., it is essential to use them according to the clinical experience, observation, and prescription methods of doctors. Research also reflects that the longer the use of Retinoids (more than 6 months), the more effective it is in reversing skin aging (both epidermal and dermal layers), and the aforementioned reaction symptoms also greatly decrease after the skin adapts.

It is reiterated that Topical Retinoids - external application of Vitamin A ointments/creams are FDA-approved as safe, effective, and suitable for long-term use in treating aging. In Hong Kong, Retinoids are prescription drugs and require a doctor's prescription. Over-the-counter skincare products claiming to contain "Vitamin A" ingredients or bearing a newly developed name similar to "Retinoids" are not expected to penetrate the skin to exert an active anti-aging effect due to their formulation, and their efficacy is questionable.

If you are looking for a truly effective method for anti-aging/reversing skin aging, or if you see no improvement when using over-the-counter skincare products, consider consulting our doctors who are familiar with Retinoids or schedule a professional skin assessment analysis 專業皮膚評估分析; depending on individual skin conditions, the doctor can select the most suitable anti-aging skincare formula for you.


Levin J, Momin SB. How much do we really know about our favorite cosmeceutical ingredients? J Clin Aesthet Dermatol. 2010 Feb; 3(2): 22-41.

Mukherjee S, Date A, Patravale V, Korting HC, Roeder A, Weindl G. Retinoids in the treatment of skin aging: an overview of clinical efficacy and safety. Clin Interv Aging. 2006;1(4):327-48.