Understanding how cosmetic ingredients interact with the skin microbiome has become essential for formulators striving to create safe, mild, and truly skin friendly products. At AAK, we set out to investigate whether vegetable oil oxidation — a natural process occurring during storage — has any measurable impact on microbiome compatibility. The results offer reassuring clarity for brands working with our Lipex range of High performance emollients.
A balanced microbiome is key to maintaining healthy skin. It supports the barrier, influences hydration and inflammation, and differs between age groups — with baby skin having a distinctly different microbial profile than adult skin. As consumers increasingly look for “microbiome‑friendly” claims, ingredient suppliers must demonstrate safety through reliable, third‑party methods.
Vegetable oils, however, are prone to oxidation, especially when exposed to heat and light. Since oxidation leads to the formation of peroxides, formulators often wonder: Does oxidized oil negatively impact the skin microbiome?
To guide our investigation, we focused on two key questions: whether vegetable oils influence the skin microbiome, and whether different levels of oxidation alter that response. To explore this, we examined three widely used AAK ingredients—Akosun, Lipex 102, and Lipex Shea. These glyceride‑based oils and butters are rich in long‑chain fatty acids, mirroring those naturally found in skin and commonly used as foundational components in modern skincare formulations.
Ingredient Interplay Methodology: High testing Across Oxidation Levels
Fresh batches of each product were filled into several jars with a headspace and stored under controlled conditions:
At pre‑defined oxidation stages, samples were frozen to preserve their status. A total of 16 samples were sent to MyMicrobiome AG (Germany) — a leading independent laboratory — for preliminary microbiome testing on both adult face/body and baby skin models. A microbiome score of 1–2 indicates “no effect”, qualifying the material as microbiome‑friendly.
”The microbiome testing revealed two clear insights. First, all samples—regardless of their oxidation level—were confirmed to be microbiome‑friendly, consistently scoring between 1 and 2 with no adverse effects observed. Even Akosun batches spanning a peroxide value range from 0.2 to 14 maintained full compatibility. Second, the data showed no correlation between oxidation and microbiome impact. Highly oxidized samples, including Lipex 102 at PV 17 and Akosun at PV 14, demonstrated no signs of microbiome disruption. This provides strong reassurance for formulators working with natural oils, which may undergo mild oxidation over time, confirming that performance and microbiome gentleness remain unaffected throughout typical product shelf life.
The observed improvements: firmer texture, reduced graininess, and increased stability, highlight the effectiveness of applying a scientific, evidence-based approach. By carefully selecting and adjusting ingredients based on an understanding of crystallization behavior, formulators can achieve substantial enhancements in product quality.
Beyond the screening tests, a full microbiome evaluation was conducted on Lipex Shea, Lipex SheaLiquid TR and Lipex SheaSolve. Lipex SheaSolve was selected as it is a non-glyceride shea ester, while the other two represents triglycerides with and without chemical modification.
All scored comfortably within the microbiome‑friendly range, confirming their suitability for sensitive‑skin applications.
The three Lipex ingredients that underwent a full, independent MyMicrobiome evaluation are now officially certified as microbiome-friendly and are listed in the public MyMicrobiome catalogue. These ingredients were chosen because they represent key chemistries and processing methods within the broader LIPEX portfolio, providing a strong indication of how the full range would perform. While screening data shows that all tested glyceride-based oils and butters exhibit consistent microbiome-friendly behavior, formal certification requires individual ingredient testing. AAK will continue to expand certification efforts if there is strong market demand and customer interest for verified microbiome-friendly claims.
What This Means for Formulators and Brands AAK’s vegetable oils and esters are microbiome‑friendly
The results were highly conclusive: Glyceride‑based and long‑chain fatty acid esters—representative of the full Lipex portfolio—show no negative impact on the skin microbiome. Even at oxidation levels as high as PV 17, no measurable effects were observed. With AAK’s internal shelf‑life oxidation limit set at a maximum of PV 5, all products remain safely within the range demonstrated to be microbiome‑friendly, giving formulators and brands strong assurance of both stability and skin compatibility.
Confidence for microbiome‑focused claims
This study enables brands to speak confidently about microbiome compatibility when formulating with Lipex products — even in high‑performance, natural, or minimal‑preservative systems where oxidation risk must be managed.
Our findings reinforce a clear message: AAK’s Lipex ingredients consistently support microbiome‑friendly formulation, even when exposed to the typical levels of oxidation that can occur during a product’s shelf life. For brands seeking gentle, natural emollients backed by solid microbiome science, the Lipex range provides a reliable and future‑ready foundation for next‑generation skin‑care innovations.