The Keratin-Regulating and Comedolytic Effects of Azelaic Acid

For those interested in skincare, the importance of pore care is well recognized. Clogged pores can lead to various skin concerns such as acne, blackheads, and whiteheads, making preventative care crucial. Today, we’ll delve into the keratin-regulating and comedolytic effects of azelaic acid, a skincare ingredient gaining attention in dermatology.

Azelaic acid is a naturally occurring dicarboxylic acid that has been used for centuries in traditional medicine. It is known to be effective in treating a variety of skin conditions including acne, rosacea, and hyperpigmentation. One of its most notable features is its ability to regulate the keratinization process, thereby preventing pore blockages and effectively treating existing comedones.

Keratinization refers to the process of forming the stratum corneum, the outermost layer of the skin. Under normal conditions, dead skin cells shed naturally and are replaced by new cells. However, when this process is disrupted, dead skin cells accumulate excessively and clog the pores. Azelaic acid helps regulate this process, thus preventing pore congestion.

The mechanism of action of azelaic acid involves altering the keratinization process of the epidermis. It affects the final stages of epidermal differentiation by proportionally reducing the size and quantity of keratohyalin granules and tonofilament bundles. In acne-prone skin, it reduces the expression of filaggrin in the stratum corneum, which leads to a decrease in the thickness of the keratin layer at the follicular orifice. Consequently, keratinocytes exhibit wider and irregular cytoplasmic distribution.

Azelaic acid also exhibits anti-proliferative activity against keratinocytes by inducing cell cycle arrest. This is associated with reduced DNA synthesis, mitochondrial damage, and expansion of the rough endoplasmic reticulum. It inhibits the synthesis of keratin precursors, thereby suppressing keratinocyte maturation. This regulation of epidermal keratinization contributes to an anti-hyperkeratotic effect, which is now clinically utilized in dermatology.

Comedones are formed when sebum and keratin accumulate inside the hair follicle. Azelaic acid effectively inhibits the formation of these comedones. Studies have shown that applying 20% azelaic acid cream to acne-prone skin twice daily for 8–12 weeks results in significant reduction or normalization of follicular hyperkeratosis both within and around the follicle. The number and size of keratohyalin granules in both follicular and epidermal keratinocytes were significantly reduced.

Another study compared the effects of 20% azelaic acid cream, 0.05% tretinoin cream, and placebo cream on acne. Thirty participants were divided into three groups and instructed to use azelaic acid cream twice daily, tretinoin cream once daily, or placebo. Both azelaic acid and tretinoin significantly reduced the number of comedones compared to placebo. The reduction in follicular hyperkeratosis achieved with azelaic acid was comparable to that of tretinoin.

Azelaic acid also possesses anti-inflammatory and antimicrobial properties, making it even more effective in treating acne. It helps combat Cutibacterium acnes (formerly Propionibacterium acnes), a key acne-causing bacterium, and reduces inflammation and erythema. This makes it particularly beneficial for inflammatory skin conditions such as rosacea and acne vulgaris.

In addition, azelaic acid improves hyperpigmentation. It inhibits tyrosinase, the enzyme responsible for melanin production. Tyrosinase catalyzes the conversion of tyrosine into DOPA and subsequently into DOPA-quinone, both of which are melanin precursors. Because dicarboxylic acids like azelaic acid do not affect normal melanocytes, they can be used to treat hyperpigmentation without causing discoloration of surrounding healthy skin.

Another benefit of azelaic acid is that it acts as a gentle exfoliant, unlike other harsh chemical exfoliants. It helps remove excess sebum and reduces acne-causing bacteria without inducing additional irritation. As a result, it improves skin texture, imparts a healthy glow, and promotes even skin tone while preventing clogged pores and breakouts.

Azelaic acid is especially effective for comedonal acne. Studies indicate that comedones were reduced by approximately 26% after four months of treatment with azelaic acid. These findings are consistent with previous research on the comedolytic activity of azelaic acid. The mechanism may involve anti-hormonal effects or modulation of keratin production.

Azelaic acid also shows efficacy against keratin plugs, which are formed by excessive accumulation of keratin in the hair follicle. It not only removes these plugs but also regulates keratin levels to prevent recurrence. By modulating keratinocyte activity—essentially the “keratin factories” of the skin—azelaic acid ensures that only the necessary amount of keratin is produced.

One consideration when using azelaic acid is that it may cause mild purging in some individuals with sensitive skin. Purging is a non-clinical term referring to a temporary worsening of acne or skin irritation as the skin adjusts to a new active ingredient. Since azelaic acid acts as a chemical exfoliant and accelerates cell turnover, this phenomenon can occur. However, it is generally temporary and not a cause for concern if the product is used cautiously and without over-stimulating the skin.

General tips for preventing clogged pores 

1. Use non-comedogenic products: Choose products labeled non-comedogenic or oil-free for makeup, skincare, and sunscreens.
2. Avoid picking or touching the skin: Picking at clogged pores or acne can worsen skin conditions rather than improve them.
3. Gentle cleansing: Washing the face twice a day with a gentle cleanser helps remove dirt, oil, and makeup, preventing pore congestion.
4. Exfoliate regularly: Exfoliating 1–2 times per week helps remove dead skin cells that could clog pores. Chemical exfoliants like beta hydroxy acids (BHAs) such as salicylic acid penetrate deep into the pores for effective cleansing.
5. Use non-comedogenic moisturizers: Hydration is important, but choose moisturizers labeled non-comedogenic. Ingredients like hyaluronic acid hydrate without adding oil.
6. Apply sunscreen daily: UV damage can thicken the skin, leading to enlarged pores. Use a broad-spectrum sunscreen with SPF 30 or higher to protect your skin and prevent pore enlargement.
7. Maintain a healthy diet: Diets high in refined sugars and dairy may increase sebum production and clog pores. A balanced diet rich in fruits, vegetables, and whole grains can promote clearer skin.

When using azelaic acid, it’s best to follow the advice of a dermatologist. Products containing 15–20% azelaic acid are generally effective, and applying them once or twice daily is recommended. Start with a patch test to observe skin reaction and gradually increase usage frequency.

Azelaic acid also works well with other skincare ingredients. It shows synergistic effects when combined with vitamin C, niacinamide, or hyaluronic acid. However, caution is advised when using it alongside retinol or other potent exfoliants, and usage frequency should be adjusted to avoid irritation.

Conclusion

In conclusion, azelaic acid is an effective ingredient for regulating keratinization and preventing comedone formation. Its anti-inflammatory, antibacterial, and pigment-reducing properties make it beneficial for addressing a wide range of skin concerns. It is particularly effective in preventing and treating pore blockages.

Pore management should be viewed as a long-term skincare goal rather than a temporary fix. By incorporating azelaic acid into a consistent skincare routine and maintaining healthy lifestyle habits, it is possible to achieve clear and healthy skin. Choosing the right product for your skin type and condition, and seeking professional guidance when necessary, will yield the best results.

If you’re struggling with clogged pores, consider incorporating azelaic acid into your skincare routine. Its exceptional abilities in regulating keratin and reducing comedones could be the solution your skin has been waiting for.