Azelaic acid (AzA) is a very unique ingredient. It is a natural component of the skin as it is a byproduct of malassezia furfur yeast, which lives on everyone’s skin. Not to be confused with hydroxy acids, it is a dicarboxylic acid that can be derived from grains such as barley, wheat, and rye, but is usually lab-engineered due to its stability.
First approved by the FDA in 2002, it comes in multiple prescription topicals, from 20% creams (Azelex) to 15% gels and foams (Finacea), as well as over-the-counter products that I will talk a bit about at the bottom of this post.
AzA is an anti-inflammatory and anti-bacterial, and is frequently used in acne and rosacea treatment, especially with sensitive skin types that are more prone to irritation from ingredients like benzoyl peroxide (BP) and tretinoin (Retin-A). In fact, in one twelve-week study, when 20% AzA was combined with glycolic acid, it showed as being just as efficacious in treating mild-to-moderate acne while offering “superior tolerability and patient approval.”
We conducted a 12-week, multicenter, randomized, double-masked, parallel-group study of the efficacy, safety, and tolerability of azelaic acid 20% cream and glycolic acid lotion compared with tretinoin 0.025% cream and a vehicle lotion to treat mild-to-moderate facial acne vulgaris. Patients treated with azelaic/glycolic acid experienced a significantly greater reduction in the number of papules, as well as a greater reduction in the number of inflammatory lesions, than those treated with tretinoin. Overall global improvement was approximately 25% in both groups. In the physician evaluations, treatment with azelaic/glycolic acid was found to cause significantly less dryness, scaling, and erythema than tretinoin. Patients also reported significantly less dryness, redness, and peeling with azelaic/glycolic acid. Significantly more patients in the azelaic/glycolic acid group than the tretinoin group reported that they felt attractive. (Abstract, source)
It has also shown to be as effective as 5% BP as well as 1% clindamycin in a randomized controlled study with 351 patients (BP gel) and 229 patients (clindamycin), with less irritation than BP (though more than with clindamycin).
Azelaic acid 15% gel proved to be as effective as BPO and clindamycin with median % reduction of the inflamed lesion (papules and pustules) of 70%, and 71% respectively. The azelaic acid gel was well-tolerated, the side effects (local burning and irritation) were distinctly less than with BPO but more pronounced than with clindamycin. Despite these side effects, the treatment was well-accepted by the majority of patients. (Abstract, source)
Due to the bacteriostatic (ability to suppress bacteria from reproduction) is thought to be why it is also anti-inflammatory.
In rosaceans, it has been shown to be potentially as effective as metronidazole (Metro-Gel and Metro-Cream) in treating subtype 2 (Papulopustular Rosacea) in addition to being more tolerable. It also sits at a higher pH range (4.8-5 pH), closer to our skin’s natural pH of 5.5¹, which may be an additional contributing factor to it’s tolerance, though nothing is for certain.
In 2015, it was also been approved for use in a foam vehicle in treatment of mild to moderate rosacea, where it has been shown to be even better tolerated than the cream and gel versions.
It is also a proven suppressant in hyper-proliferation of keratin, which is a factor in conditions such as acne. A small study (45 patients) shows that it may help conditions like keratosis pilaris as well due to it’s ability to reduce inflammation by inhibiting “the reactive oxygen species of neutrophils” (a type of white blood cell), though not enough to be considered significantly better than simply moisturizing.
Results: Of the 45 patients that enrolled in the study, only 24 patients were present at 3 month follow-up. 92% of azelex-treated skin and 83% of [Cetaphil Moisturizing Cream]-treated skin showed improvement in hyperkeratosis and/or erythema after 3 months of therapy. … This small study demonstrates that both azalex and cetaphil is effective in treatment of keratosis pilaris, and that one is not significantly better than the other in reducing the degree of hyperkeratosis or erythema. (Source)
It may also have some benefits for sufferers of perioral dermatitis (or “steroid rosacea,” as it used to be called). A small study of 10 children aged 3-12 suffering from PD were evaluated and treated with 20% azelaic acid cream.
Treatment with 20% azelaic acid cream led to complete resolution of skin lesions after 4 to 8 (mean 5.4) weeks in all patients. Transient exacerbation of skin condition with a peak between the 2nd and 6th day of treatment could be observed in three patients. Side effects of 20% azelaic acid cream were registered in six patients and were predominantly present in the first 2 weeks of treatment. Side effects were minimal and became rarer with ongoing treatment. No recurrences were seen within a follow-up period of 2 to 8 (mean 4.4) months. Treatment with 20% azelaic acid cream could provide an effective and safe alternative therapeutic option in children with nongranulomatous periorificial dermatitis. (Abstract, Source)
It is also a tyrosinase inhibitor, with a special affinity for abnormal melanocytes, making it ideal in treatment of melasma or post-inflammatory hyperpigmentation (PIH). In fact, it is much safer and typically more preferred to hydroquinone, which is a skin lightener that tends to target all skin cells and has created concerns due to potentially causing tumors in mice.² In an open study comparing 20% AzA twice daily to 4% hydroquinone, it showed to be just as effective if not more effective than the hydroquinone in reducing mild melasma.
In conclusion, this study suggests that 20% azelaic acid cream applied twice daily may be more effective than hydroquinone 4% in reducing mild melasma. However, because this was an open trial, it is suggested that further studies involving large groups of
patients be conducted to achieve a more conclusive result. (Conclusion, Source)
In another study involving AzA (15%), waiting until after moisturizing to apply AzA resulted in greater penetration of the AzA. This did not occur with all moisturizers however, and was only seen in moisturizers that lacked large amounts of occlusives. It should also be noted that in a small study, gluconolactone (PHA) was shown to be helpful when combined with Azelaic Acid 15%.³
Unfortunately, it does take time to work and the side-effects when initially starting off can be aggravating. The most common side-effects are itching and stinging as well as mild dryness or peeling. This tends to resolve within 4 weeks. This can be difficult to push through. As someone who uses AzA, I can say that the initial itching upon application can feel very intense and aggravating to deal with, though icing my skin helped me push through the worst days. Your mileage may vary.
It takes about 24 weeks to work in cases of melasma and up to two months in acne cases.
One important note (mentioned by Dr. Dray in her wonderful video on AzA) is that it can lighten and “hide” some forms of melanoma, particularly lentigo maligna melanoma. This does not treat it or cure it, and can in fact hide the melanoma. Please get a skin check before self-treating abnormal dark spots with over-the-counter azelaic acid products.
- Disruption of the transmembrane pH gradient–a possible mechanism for the antibacterial action of azelaic acid in Propionibacterium acnes and Staphylococcus epidermidis
- Induction of Renal Cell Tumors in Rats and Mice, and Enhancement of Hepatocellular Tumor Development in Mice after Long‐term Hydroquinone Treatment
- A Guide to the Ingredients and Potential Benefits of Over-the-Counter Cleansers and Moisturizers for Rosacea Patients
- Dr Dray – Azelaic Acid