I conducted research a few years ago on human skin samples to understand how various stressors affect skin health. This research was prompted by my own skin problems, which persisted despite using a range of products from different brands. These products, regardless of their origin—dermatological, natural, or luxury—shared similar ingredient profiles. This homogeneity stems from the fact that most skin care products are manufactured in the same factories, differing only in packaging and branding. About 99% of skin care brands fall into this category.
What bothered me was the lack of substantive knowledge in the skin care industry. Most advice found on the Internet is a hodgepodge of information from unverified sources, and even so-called scientific articles often repeat the same claims. Few, if any, individuals have conducted independent experiments to validate these claims.
This realization led me to research why acne persists despite the promises of products that claim to cure it. I dissect each ingredient, suspecting that many in the skin care industry lack a deep understanding of the biological effects of their formulations. Skin care has become a giant echo chamber, often driven by trends and cult followings rather than evidence-based practices.
My approach was simple: identify what works and what doesn’t, with the goal of either incorporating effective ingredients into my formulations or avoiding harmful ones altogether. Through my experiments, I discovered several common ingredients to avoid.
Alcohol: This ingredient dries out the skin, causes cell damage and increases susceptibility to disease. Contrary to popular belief, alcohol does not effectively remove oil. Instead, it stimulates the skin to produce more oil, often of an inflammatory nature, exacerbating acne. A study published in Dermatitis (2003) confirmed that alcohol-based products can disrupt the skin’s barrier function, leading to increased irritation and dryness.
Fragrance: Fragrances, including essential oils and flower extracts, can cause significant damage to the skin. Despite being marketed as safe for sensitive or acne-prone skin, these ingredients often lead to irritation and damage. Their inclusion is primarily for consumer appeal, highlighting the industry’s priority of sales over skin health. Research in Contact dermatitis (2014) highlighted the high prevalence of allergic reactions related to fragrances in cosmetics, highlighting their potential to damage sensitive skin.
My experiments extended to two commonly used ingredients in acne treatments: glycolic acid and benzoyl peroxide. When exposing skin samples to these ingredients, I observed similar damage to that caused by alcohol and perfume. This included damage to the plasma membrane and loss of vital components of the cellular and extracellular matrix.
To further investigate these effects, I created two topical formulations: one with glycolic acid and benzoyl peroxide, and one without. The formulation without these ingredients consistently resulted in healthier, more resilient skin.
Glycolic Acid: This common exfoliant is a known sensitizer, making the skin more vulnerable to damage. Research shows that glycolic acid’s role in increasing sun sensitivity is significant. Many warnings about sun exposure combined with exfoliants come specifically from the use of glycolic acid. A 2016 study in Clinical, Aesthetic and Research Dermatology demonstrated that glycolic acid treatments increased transepidermal water loss and skin sensitivity, confirming its sensitizing effects.
Benzoyl peroxide: This ingredient causes oxidative stress due to its superoxide, leading to cell damage and inflammation. While it can temporarily reduce acne by killing bacteria, it compromises the integrity and long-term health of the skin. A study published in Journal of Dermatological Science (2018) revealed that benzoyl peroxide causes oxidative damage to keratinocytes and reduces the skin’s ability to recover from environmental stressors.
Through this research, I have come to the conclusion that these two ingredients, while widely recommended, are major contributors to skin deterioration. The skin care industry’s reliance on them reflects a larger pattern of prioritizing short-term results over sustainable skin health. Consumers often remain trapped in a cycle of damage and treatment, unable to understand why their skin is not improving. The solution lies in ditching these harmful ingredients and adopting a science-backed skin care approach.
I decided to model the No. 9 different, which uses poly hydroxy acids, which are larger and therefore exfoliate more slowly leading to a better effect on the skin. Designed with people who have damaged skin to help with their skin barrier.
Unlike benzoyl peroxide which just kills the bacteria by killing the skin, creating a never ending cycle of acne, the No. 9 teaches the skin to become acidic, leading to greater resilience. The skin naturally becomes capable of killing bacteria on its own in the way it is supposed to do naturally.
