Benefits of Lactic Acid and Azelaic Acid for Sensitive, Eczema and Rosacea-Prone Skin

Many of those with sensitive skin, eczema, and rosacea often feel apprehensive when they hear the word "acid" in skincare ingredients. They tend to believe that all "acid" substances are irritating and should be avoided. The truth is, not all ingredients with the word "acid" are harsh for the skin. In fact, some of them are star ingredients used by dermatologists to treat and improve sensitive skin, eczema, and rosacea!

Today, let's delve into two of these ingredients——Lactic Acid and Azelaic Acid.

What is Lactic Acid?

Lactic acid, derived from milk, is a gentle and hydrating type of alpha-hydroxy acid that naturally occurs in our bodies, and is one of the main substances in the skin's natural moisturizing factor (NMF). Unlike common beliefs, not only does lactic acid gently exfoliate, it also possesses powerful properties in improving sensitivity, eczema, and rosacea issues!

| Lactic Acid Skin Benefits ① Gently Exfoliates

In skincare products, lactic acid gently exfoliates the skin. Since it is larger in molecule size, it only works on the surface of the skin and does not cause irritation.

Do sensitive skin, eczema, and rosacea-prone skin need exfoliation though? The answer is YES!

As we age, the speed and efficiency of the cell renewal process significantly decrease. In our 20s, it takes approximately 14-21 days for cell turnover, gradually increasing to 28-45 days in our 30s, 45-60 days in our 40s, and even 90 days or more in our 50s and 60s. When aging dead skin cells accumulate on the skin's surface and become progressively harder and uneven, the skin becomes dry, rough, and dull. This thick layer of dead skin cells can also trap excess sebum, dirt, and even bacteria and inflammation, exacerbating issues like sensitivity, eczema, and rosacea. Additionally, the accumulated dead skin cells send signals to the skin, causing the mother cells deep within the epidermis to stop dividing and generating new cells. This ultimately slows down the natural regeneration and renewal process of the skin as a whole, weakening its overall function and making it even more challenging to improve conditions like sensitivity, eczema, and rosacea！

But isn't scrubs better for sensitive skin, eczema, and rosacea than acid? Definite no!

Firstly, the back-and-forth friction during physical exfoliation has a high chance of irritating already inflamed skin. Secondly, it may remove healthy skin and cause micro-tears that are not visible to the naked eye, whilte damaging the skin barrier and significantly reducing the skin's ability to retain moisture and protect against bacteria and allergens. Therefore, scrubs are in fact absolutely not suitable for sensitive skin, eczema, and rosacea.

In other words, when it comes to exfoliation for sensitive, eczema, and rosacea-prone skin, lactic acid is actually the top choice!

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| Lactic Acid Skin Benefits ② Smoothes Fine Lines and Wrinkles

To improve fine lines and wrinkles, it is necessary to approach it from multiple angles. Lactic acid can help diminish these frustrating lines through four different channels:

• Thick layers of aging dead skin cells make any wrinkles, especially expression lines, appear more severe than they actually are. Lactic acid gently removes dead skin cells, promotes cell turnover, and smoothes the skin, and in turn reduces the appearance of fine lines and wrinkles.
• Lactic acid can hydrate the skin while increasing the level of ceramides within the skin. This not only makes wrinkles appear less noticeable, but also helps to keep the skin hydrated and improves its overall appearance.
• Lactic acid stimulates the production of collagen and elastin, which in synergy provide structure and support to the skin. This helps strengthen the skin's foundational structure, increase skin elasticity, and reduce wrinkles.
• By promoting cell turnover, lactic acid eliminates aging and damaged skin cells and stimulates the growth of new, healthy cells. This renewal process helps improve the overall texture of the skin and makes wrinkles less prominent.

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| Lactic Acid Skin Benefits ③ Reduces Hyperpigmentation, Brightens Skin

Research has shown that lactic acid not only has the power to brighten skin and fade hyperpigmentation, but also significantly improves melasma (also known as hormonal spots or liver spots, thanks to its effectiveness in approaching pigmentation from four aspects:

• The exfoliating action of lactic acid helps to lighten areas of pigmentation by promoting the shedding of the aged, dead skin cells on the skin's surface.
• When old melanin cannot move to the skin's surface and shed, pigmented acne marks and hyperpigmentation will take much longer to fade. Lactic acid stimulates cell turnover and promotes the growth of new, healthy skin cells. This in turn helps reduce pigmentation, even skin tone, and brighten skin.
• Melanin is what makes up pigmentation and acne marks. Lactic acid can reduce the production of melanin by inhibiting the activity of tyrosinase, thus lightening spots and improving pigmentation issues.
• When the skin is dry and dehydrated, it will appear dull and lackluster. Lactic acid's hydrating properties help enhance the skin's transparency, resulting in a more radiant, youthful complexion.

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| Lactic Acid Skin Benefits ④ Hydrates Skin

Lactic acid is a type of humectant. This means that its unique structure and properties not only prevent the skin from drying out, but also help bring a significant amount of water into the skin, and hydrate skin cells！

In addition, factors such as aging, excessive cleansing, and the use of foaming cleansers can make the skin increasingly alkaline; when the skin becomes alkaline, the barrier becomes compromised, leading to dryness, sensitivity, and even exacerbating inflammatory conditions like acne, rosacea, and eczema. Lactic acid helps regulate the skin's pH value, thereby improving the skin's ability in retaining hydration and reducing water loss.

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| Lactic Acid Skin Benefits ⑤ Highly Antibacterial

Research has shown that lactic acid exhibits antibacterial properties and reduces inflammatory responses. This not only helps alleviate sensitivity and redness issues, but also improves conditions like eczema, rosacea, acne, and even psoriasis, which are all essentially inflammatory skin conditions.

| Lactic Acid Skin Benefits ⑥ Increases Ceramides in Skin

Ceramides are one of the most important moisturizing components of the skin. When there is a deficiency of ceramides in the skin, the skin barrier function is easily compromised, leading to inflammation, acne, dryness, and water loss.

Research has confirmed that lactic acid effectively increases the levels of ceramides in the skin's stratum corneum, thereby improving the skin barrier function and reducing water loss. When the barrier is healthy, the skin is also better able to resist allergens and bacterial invasion. This means that using lactic acid can make the skin more hydrated, plump, and firm, reduce dry lines and fine lines, while helping to improve even sensitivity and inflammation issues.

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What is Azelaic Acid?

Azelaic Acid is a skincare ingredient that naturally occurs in grains such as wheat, rye, and barley. Not only does it possess many remarkable skincare benefits, it also has a pH value that falls within the slightly acidic range of 4.5 to 5.5, which perfectly matches the pH of healthy skin. For this reason, it is commonly used by dermatologists as an effective ingredient for treating sensitivity, eczema, rosacea, and acne.

| Azelaic Acid Skin Benefits ① Highly Anti-Inflammatory, Alleviates Redness

In essence, sensitivity, eczema, rosacea, and even acne, are all the result of skin inflammation. Azelaic Acid can effectively reduce inflammation issues via three angles:

• Free radicals are highly reactive molecules that cause oxidative stress, leading to inflammation. Azelaic Acid, with its potent antioxidant properties, can fight and neutralize free radicals, which in turn, alleviates inflammation.
• Mitochondrial oxidoreductases are elements involved in cellular energy production. When these oxidoreductases are overactive, an excess of reactive oxygen species (ROS) is produced within skin cells, which can trigger inflammation. Azelaic Acid can inhibit these enzymes and reduce the generation of ROS, helping to suppress inflammation.
• Neutrophils, a type of white blood cells involved in immune responses, can produce pro-inflammatory oxygen derivatives, such as superoxide anions and hydrogen peroxide, when they are overly active. Azelaic Acid can help reduce the generation of these pro-inflammatory molecules, thus easing inflammation.

Apart from inflammation, the redness that comes with sensitive, eczema and rosacea-prone skin is often a result of an overactive defense mechanism in the skin. Some receptors in the skin inherently function as danger sensors that detect environmental threats, and while they generally aid in resisting bacterial or allergenic attacks, when in overdrive, they can lead to sensitivity and rosacea flare ups. Azelaic Acid helps balance and bring these receptors back under control, fundamentally improving issues related to sensitivity, redness, rosacea, and eczema.

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| Azelaic Acid Skin Benefits ② Anti-Microbial, Antibacterial, Anti-Acne

As one of the main ingredients used by dermatologists to treat rosacea and acne, Azelaic Acid has powerful anti-microbial, antibacterial and anti-acne properties:

• Azelaic Acid has antibacterial properties, particularly in terms of inhibiting the growth of Propionibacterium acnes and Staphylococcus epidermidis, which are commonly associated with acne. By reducing the number of bacteria on the skin, various inflammatory issues, including acne, naturally decrease.
• The anti-inflammatory properties of Azelaic Acid help alleviate inflammation associated with acne, sensitivity, eczema, and rosacea. By reducing inflammatory responses, redness, swelling, itching, and discomfort can be relieved.
• The process of skin keratinization, which involves the formation and shedding of dead skin cells, is an important part of healthy skin. However, in skin prone to acne, psoriasis, eczema, and rosacea, this process is often disrupted. When dead skin cells accumulate abnormally, pores can become clogged while trapping bacteria within the skin, which then easily lead to acne and various inflammatory issues. Azelaic Acid helps normalize this keratinization process, thus reducing clogged pores and the accumulation of bacteria within the skin.
• Sebum is an oily substance secreted by the sebaceous glands of the skin. Skin needs sebum to stay healthy, but excess sebum production can contribute to acne. Azelaic Acid helps regulate sebum production, thereby reducing the occurrence of acne.

| Azelaic Acid Skin Benefits ③ Reduces Hyperpigmentation, Brightens Skin

Azelaic Acid is not only good for fighting inflammations, bacteria, allergens and acne. In fact, it is also highly effective in fading pigmentation and brightening skin!

• Melanin is the main culprit behind dark spots and pigmentation. When the activity of tyrosinase, an enzyme in the skin, is in overdrive though, melanin production increases significantly. Azelaic Acid can inhibit tyrosinase to reduce the production of melanin, thereby fading pigmentation and brightening skin.
• Melanin can transfer from melanocytes (cells that produce melanin) to surrounding skin cells, leading to the formation and accumulation of dark spots. Azelaic Acid helps interrupt this melanin transfer process and kills abnormal melanocytes, and prevents the spread of melanin accumulation in specific areas. Ths result is a complexion that is brighter and more even.
• Inflammation is a major cause of pigmentation and increased melanin production, as it sends tyrosinase activity into overdrive. Azelaic Acid, with its anti-inflammatory properties, helps reduce visible and underlying inflammation in the skin, slow down melanin production, and thus, decreasing the chances of pigmentation.
• When old melanin cannot move to the skin's surface and shed, pigmented acne marks and hyperpigmentation will take much longer to fade. Lactic acid stimulates cell turnover and promotes the growth of new, healthy skin cells. This in turn helps reduce pigmentation, even skin tone, and brighten skin.

| Azelaic Acid Skin Benefits ④ Reduces Blackheads and Whiteheads

Azelaic Acid can improve the disorderly growth of skin cells within the hair follicles by inhibiting the proliferation and differentiation of keratinocytes. This not only helps maintain clear pores but also reduces blackheads and whiteheads, and as a result, the pores will appear smaller and tighter!

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