TL;DR
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A 2026 study evaluated a six-ingredient concentrate containing 10% azelaic acid and 0.1% retinal in 23 participants over eight weeks. The researchers reported statistically significant improvements versus the vehicle, but the results apply to the complete formulation and do not establish the effect of Azepur99® alone.
A study published in the International Journal of Cosmetic Science in 2026 reported improvements in redness, surface irregularities, pore parameters and texture after participants used a concentrate containing 10% azelaic acid and 0.1% retinal for eight weeks. The randomized, split-face study included 23 completers and compared the finished product with its vehicle; the results apply to the formulation as a whole, which used Azepur99® as its azelaic acid ingredient.
Gaudicheau, Ahlström, Gillbro and Åkerström evaluated the concentrate in an eight-week, prospective, randomized, vehicle-controlled split-face study. Efficacy assessments used Antera 3D imaging, standardized photography and participant self-assessments. The report says the active formulation produced statistically significant improvements compared with the vehicle, including an 18.1% improvement in overall redness, a 12.7% improvement in surface irregularities, a 22.3% improvement in pore parameters and a 5.6% improvement in skin texture. Maximum redness intensity fell by 5.2%.
The product contained six ingredients: squalane, azelaic acid, caprylic/capric triglyceride, hydrogenated vegetable oil, Hordeum vulgare seed flour and retinal. The study authors also reported participant assessments: 95% said their skin felt calmer, 87% reported improved overall skin condition and 82% reported reduced oiliness. Improvements in pimple size or severity and in the number of pimples were reported by 78% and 74%, respectively. These are self-reported outcomes; the report also describes instrumental assessments of skin changes.
Azepur99®, supplied by Azeco Cosmeceuticals, was the azelaic acid used in the formulation. The source describes it as cosmetic-grade material with at least 99% purity, natural origin and micronized particle size. Azeco did not participate in the study’s design, execution, data analysis or publication, according to the report. The study did not test Azepur99® as a standalone ingredient.
Results Apply to the Full Concentrate
The study offers a clinical evaluation of a finished product combining 10% azelaic acid with 0.1% retinal, rather than evidence about either ingredient on its own. That distinction matters to consumers and product developers: the measured outcomes reflect the tested mixture, its six-ingredient base and the study conditions. They cannot establish that Azepur99® alone produced the reported changes.
The results also provide a defined example of how the actives were formulated together in an anhydrous concentrate and assessed over eight weeks. The improvements were measured against a vehicle in a split-face design, giving the comparison a specific scope. They do not establish how the concentrate performs for all people with blemish-prone skin, how it compares with other products, or whether effects persist after use ends.
For readers considering the findings, the participant reports offer a useful view of perceived changes alongside imaging and photography. However, the study had 23 participants complete it, and the supplied report does not establish broader effectiveness beyond the tested group and period.
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How the Eight-Week Test Worked
The study addresses interest in skincare products for blemish-prone skin and visible redness, but its stated contribution is narrower than a general assessment of azelaic acid. It tested one minimalist, anhydrous concentrate that paired azelaic acid with retinal and compared it with a vehicle over eight weeks. A split-face approach means the product and comparator were assessed on different sides of participants’ faces, according to the study description.
The paper is titled “Efficacy and safety of a novel anhydrous 0.1% retinal and 10% azelaic acid concentrate for blemish-prone skin: An eight-week randomized prospective split-face, vehicle-controlled study.” It is listed in the International Journal of Cosmetic Science in 2026, with DOI 10.1111/ics.70131. The supplied report identifies the study authors as Gaudicheau, Ahlström, Gillbro and Åkerström and says Skinome Research evaluated the formulation.
Azeco Cosmeceuticals supplied the Azepur99® ingredient, while the report states that the company had no role in the study’s conduct or publication. That disclosure helps clarify the supplier’s relationship to the research. It does not change the central limitation: the tested intervention was the complete concentrate, not an isolated sample of the supplied azelaic acid.
Limits of the Reported Evidence
The supplied material does not provide the full numerical results for every measurement, participant characteristics, details of adverse events, or the study’s complete statistical analysis. Although the paper title includes safety, the summary here gives no specific safety findings. Those details should not be inferred from the reported efficacy outcomes.
It is also unclear from the supplied summary how long any observed changes lasted beyond the eight-week study, whether participants continued using the product, or how the formulation would perform in a larger or more diverse group. The percentages reported for redness, pores and texture are study outcomes versus the vehicle as described by the source; the summary does not state a separate comparison baseline beyond that comparator.
The consumer-assessment percentages reflect participants’ reports, while the imaging and photography measures represent different forms of assessment. The source does not provide enough detail here to independently assess the size of every effect or determine which ingredients contributed to it. In particular, no result can be assigned to Azepur99® alone based on this study.
Further Evidence Will Clarify Reach
The next useful step for readers is to consult the full journal paper for its complete methods, participant profile, statistical results and safety reporting. The reference provided is Gaudicheau C, Ahlström M, Gillbro JM and Åkerström U, published in the International Journal of Cosmetic Science in 2026, DOI 10.1111/ics.70131.
Further studies could test whether the reported findings hold in larger groups, over longer periods, or with formulations that isolate azelaic acid from retinal and the other ingredients. Until such evidence is available, the current report supports a limited conclusion: the complete 10% azelaic acid and 0.1% retinal concentrate showed improvements versus its vehicle during an eight-week evaluation, while the individual contribution of each ingredient and the durability of outcomes remain undetermined.
Key Questions
What product did the study evaluate?
It evaluated an anhydrous concentrate containing 10% azelaic acid and 0.1% retinal, alongside four other ingredients, over eight weeks.
What results did the researchers report?
The report describes statistically significant improvements versus the vehicle in overall redness, surface irregularities, pore parameters and skin texture. It also includes participant reports about calmer-feeling skin, oiliness and pimples.
Did the study prove Azepur99® works by itself?
No. Azepur99® was the azelaic acid ingredient in the tested product, but the study assessed the complete formulation. It does not show the effect of Azepur99® alone.
How many people completed the study?
Twenty-three participants completed the eight-week study, according to the supplied report.
Source: rss
