A positive result in a cell culture dish once supported many cosmetic claims: a collagen marker increased, or an inflammatory pathway decreased. But consumers buy products for what happens on their skin. As claims become more ambitious, evidence standards are shifting. In vitro remains valuable, but relying on it as the entire proof story is increasingly outdated. Why are in vitro skin models losing credibility? Regulators and consumers are asking a harder question: “Does this model predict what happens in real human skin?” In vitro systems offer valuable biological insight, but they simplify a complex organ. Skin is an ecosystem of immune signalling, vascular influence, environmental exposure and microbes. What can in vitro never fully capture? Skin responses vary between individuals due to age, genetics, hormones, lifestyle and microbiome differences. The microbiome is especially complex, involving microbial interactions, immunity, metabolites and barrier function. Simplified models can provide valuable insights, but they cannot fully predict real-world skin responses. Where does in vitro still earn its place and where does it become a trap? In vitro remains a powerful tool in cosmetic science when used for the right questions. It is valuable for: · Screening ingredients · Supporting safety assessment · Comparing formulations The risk is turning a biological signal into a consumer promise. A fibroblast producing more collagen does not prove fewer wrinkles, and a growth assay does not prove improved microbiome health. The mistake is not using in vitro; it is asking it to prove more than it can. What does in vivo multi-omics actually look like? Multi-omics sounds complex, but the principle is simple: measure multiple biological layers together. A study may combine microbiome sequencing, metabolomics, transcriptomics and clinical measurements such as hydration, redness or barrier function. Instead of asking “did one marker change?”, we can ask: • Did the product alter microbial communities? • Did those changes influence biological pathways? • Did skin function improve? • Did consumers experience a measurable benefit? This moves cosmetic testing from isolated signals towards a systems-level understanding of skin. Will regulators ban in vitro-only substantiation? Probably not. The bigger shift is the rising expectation for evidence quality. Regulators are increasingly focused on whether evidence matches the claim. Validated in vitro methods remain appropriate for safety and mechanistic questions, but claims involving complex outcomes such as inflammation or visible ageing require evidence that reflects real-world effects. How fast should brands move? Strategically, not universally. Routine safety testing and early screening still have a place, but flagship products built on complex biological claims must move to a relevant human evidence base. In vitro is for understanding. Human studies for proving. Multi-omics for explaining. The strongest brands will not abandon laboratory models. They will use them within a fuller evidence ecosystem.

The vaginal ecosystem is not just a microbial community. It is a host-microbe system shaped by hormones, immunity, metabolites, and local chemistry. Multiomics, a combination of microbiome, metabolome, immune signals, and genomics, moves the field beyond "which bacteria are present?" to what they are doing, how the host responds, and what that means for health. What we know This approach has transformed understanding of the vaginal ecosystem, revealing complex host–microbe interactions, functional diversity, and links to BV, reproductive outcomes, and gynaecological cancers 1. The mix of small molecules in the vagina (metabolites) is one of the best ways to understand its state. Certain fats (lipids) help show levels of inflammation, while amino-acid by-products reflect which bacteria are present and the pH 2. The vaginal environment is different for everyone and changes over time. Simple “normal” vs “abnormal” labels miss important differences between people 3. Recent advances include AI-powered diagnostic models that integrate microbiome and metabolome data for improved BV detection 4. Impact and potential Vaginal multiomics opens real innovation pathways. Microbiome-compatible formulation: Designing intimate care that avoids disrupting the vaginal microbiome Prebiotic and postbiotic development: Targeting favourable metabolic environments, not simply eliminating bacteria. Longitudinal testing and claims: Shift from single timepoint testing to tracking changes over time (e.g. across cycles, treatment use), enabling more meaningful and defensible claims. Subtype-driven product design: Move beyond one-size-fits-all “intimate care” by developing products tailored to different dysbiosis or symptom subtypes identified through multiomics. Our position At Sequential, we approach the skin as an ecosystem, not a single pathway. Our focus is on generating measurable, real-world evidence of how formulations interact with both the barrier and the microbiome simultaneously. Using integrated multi-omics approaches, we can quantify changes in lipid composition, protein expression, microbial activity, and overall skin resilience over time. By testing formulations on diverse skin types and environments, using our global sample database, we generate insights that reflect real-world use rather than idealised conditions. References 1. Ottinger, S., et al. (2024). The human vaginal microbiota. Curr Opin Microbiol, 77, 102422. 2. Bokulich, N., et al. (2022). Multi-omics integration in the cervicovaginal microenvironment. PLoS Comput Biol, 18, e1009876. 3. Challa, A., et al. (2024). Multi-omics biomarkers of bacterial vaginosis. J Eur Acad Dermatol Venereol, 38, 1152–1165. 4. Saluzzo, S., et al. (2024). AI-powered multiomics in bacterial vaginosis. J Eur Acad Dermatol Venereol, 38,999 -1000.

The skin barrier is often described as a wall. In reality, it’s more like a living ecosystem. At its surface sits the skin microbiome, a complex community of bacteria, fungi, and viruses that don’t just exist on the skin, but actively help it function. Rather than being passive, the microbiome works alongside the physical, chemical, and immune layers of the barrier to maintain resilience, regulate inflammation, and protect against environmental stress. When this relationship is balanced, skin performs optimally. When it’s disrupted, both barrier function and skin health can decline. What we know The microbiome acts as a co-regulator of skin function, working alongside the barrier and immune system 1. The microbiome is a diverse, site-specific ecosystem. Oily, moist, and dry areas host distinct communities 2,3. Commensal microbes actively support barrier integrity through effects on keratinocytes and lipid balance 1, 4. Dysbiosis, through reduced diversity, is associated with conditions such as acne, atopic dermatitis, and psoriasis, often alongside barrier disruption 1, 5. Industry impact and potential For formulation, this changes the goalposts. It’s no longer enough to protect the barrier or consider the microbiome in isolation. The focus should be on supporting the system as a whole. Barrier-first design: Prioritising formulations that maintain hydration, pH, and lipid balance to create conditions in which beneficial microbes thrive. Microbiome-compatible actives: Using prebiotics, postbiotics, and fermented ingredients where evidence supports functional benefit. Precision skincare: Leveraging microbiome profiling and multi-omic data to match products to different skin states, environments, and life stages. Our position At Sequential, we approach the skin as an ecosystem, not a single pathway. Our focus is on generating measurable, real-world evidence of how formulations interact with both the barrier and the microbiome simultaneously. Using integrated multi-omics approaches, we can quantify changes in lipid composition, protein expression, microbial activity, and overall skin resilience over time. By testing formulations on diverse skin types and environments, using our global sample database, we generate insights that reflect real-world use rather than idealised conditions. References Lee, H, et al. (2022). Skin Barrier Function and the Microbiome. Int J Mol Sci, 23. Smythe, P, et al. (2023). The Skin Microbiome: Current Landscape and Future Opportunities. Int J Mol Sci, 24. Prajapati, S, et al. (2025). Microbiome and Postbiotics in Skin Health. Biomedicines, 13. Harris-Tryon, T, et al. (2022). Microbiota and Maintenance of Skin Barrier Function. Science, 376, 940–945. Scharschmidt, T, et al. (2025). Skin Microbiome and Dermatologic Disorders. J Clin Invest, 135.

Skin repair is not simply about moisturising; it is a precisely coordinated biological response. From minor barrier disruption to full wound healing, the skin activates a sequence of processes to restore function, protect against further damage, and minimise long-term impact. In most cases, this process restores continuity, not perfection. Adult skin typically repairs with some level of structural compromise, making the balance between effective repair and excessive scarring a critical focus. What we know Skin repair is a multi-phase process involving inflammation, cell proliferation, extracellular matrix rebuilding, and remodelling 1. Most adult skin heals through repair (with scarring) rather than true regeneration of original structure 2. Barrier disruption increases TEWL, triggering keratinocyte activity, lipid synthesis, and inflammatory signalling 3. Effective repair is linked to restored hydration, improved lipid organisation, and reduced irritation risk 4. The balance between inflammation and regeneration is a key determinant of healing quality and outcomes 5. Industry impact and potential Skin repair is shifting skincare towards more targeted, biology-led formulation: Recovery first design: Designing products that prioritise reducing TEWL, preserving lipid organisation and minimising unnecessary irritation, before cosmetic goals. Phase-specific formulations: Moving beyond one-size-fits-all "repair" to products built for distinct needs Inflammation control: Developing actives and combinations that calm the inflammatory cascade at the right time, reducing chronic low-grade inflammation that compromises repair and accelerates ageing. Next-generation delivery systems: Drawing on advances in wound care, creating vehicles that actively maintain a stable repair environment rather than just carrying actives. Our position At Sequential, we support brands in moving from broad “skin repair” claims to clearly defined, evidence-based outcomes. Our approach combines in vivo testing with molecular-level analysis to understand how formulations influence key aspects of repair, including barrier recovery, inflammation, and skin resilience. Drawing on a global database of 50,000+ biological samples, we provide insights across diverse skin types, conditions, and environments, supporting the development and substantiation of repair-focused formulations with greater clarity, confidence, and scientific grounding. References 1. Sorg, H, et al. (2016). Skin Wound Healing: An Update on Current Knowledge and Concepts. Eur Surg Res, 58, 81–94. 2. Peña, O, et al. (2024). Cellular and Molecular Mechanisms of Skin Wound Healing. Nat Rev Mol Cell Biol, 25, 599–616. 3. Tottoli, E, et al. (2020). Skin Wound Healing Process and Emerging Technologies. Pharmaceutics, 12. 4. Lee, H, et al. (2022). Skin Barrier Function and the Microbiome. Int J Mol Sci, 23. 5. Atallah, C, et al. (2025). Bioengineered Skin Microbiome in Cosmetics. Cosmetics, 12.

Ectoin is a naturally occurring small molecule produced by bacteria that survive extreme conditions: heat, dryness, and high salt. In skincare, it does something similar: it wraps a layer of organised water around skin cells and proteins, helping them stay stable under stress. This reduces transepidermal water loss (TEWL) and helps skin resist environmental stress from the inside out. This makes it a different kind of barrier ingredient, one that stabilises rather than simply shields. What we know Ectoin works by forming a protective water layer around cell membranes, which helps stabilise the skin barrier rather than simply sitting on top of it1. In clinical studies, 5.5–7% ectoin formulations improved dryness, itch, and dermatitis scores in atopic and retinoid-stressed skin, with a strong safety record2. Topical ectoin reduces TEWL and inflammatory cytokines, with effects demonstrated in both healthy and barrier-compromised skin3. Ectoin is generally well tolerated, with only mild, transient sensations reported in some cases; however, current evidence is limited, with many studies small or short, meaning more rigorous trials are needed4. Industry impact and potential Ectoin presents an opportunity to move it beyond "gentle hydration" into barrier-performance science with measurable endpoints: Barrier-first formulation: Combining ectoin with ceramides and humectants in leave-on systems designed for sensitive, over-exfoliated, or retinoid-stressed skin. Stress and recovery positioning: Testing ectoin under realistic conditions such as being exposed to pollution, cold-weather stress, and post-procedure skin to generate evidence where barrier resilience is the primary claim of a formulation. Clinical design upgrade: Investing in randomised, longer-duration trials with objective endpoints such as TEWL, hydration, and redness imaging to build a defensible evidence base. Platform thinking: Using ectoin as part of a broader barrier-health story, not as a solo hero ingredient that has to carry the whole product. Our position At Sequential, we see ectoin as both a formulation and an evidence opportunity. Through our end-to-end clinical testing platform, we support brands from study design to data interpretation and combine in vivo microbiome and biophysical testing, targeted biomarker analysis, and real-world study conditions to generate meaningful and relevant data. By leveraging our 50,000+ database of samples and formulation insights, we can help translate ectoin’s mechanism into measurable outcomes. References 1. Bujak, T., et al. (2020). Ectoine–surfactant complexes in cleansing cosmetics. Molecules, 25, 1433. 2. Kauth, M., et al. (2022). Topical ectoine for inflammatory skin diseases: a systematic review. Dermatol Ther, 12, 295–313. 3. Załęska, I., et al. (2025). Ectoine effects on CO₂ laser-damaged skin. Molecules, 30, 2470. 4. Graf, R., et al. (2008). Ectoine as a natural cell protectant. Clin Dermatol, 26, 326–333.

Male pattern baldness, also known as androgenetic alopecia, is the most common form of hair loss in men. Despite this, it is often dismissed as a cosmetic inconvenience or ageing. For many, hair loss is neither trivial nor purely aesthetic; it can affect identity, confidence and psychological wellbeing. Growing interest in scalp health and hair retention has increased demand for approaches that go beyond concealment. This has caused a shift to focus on understanding why hair loss occurs, why it progresses differently between individuals, and what supports hair retention over time. Addressing male pattern baldness responsibly means moving past surface-level claims and toward solutions informed by biology and long-term outcomes. What we know Male pattern baldness is a progressive condition in which genetically susceptible hair follicles gradually shrink, producing finer, shorter hairs before visible growth stops, even though follicles often remain biologically active 1. Sensitivity to dihydrotestosterone (DHT), rather than hormone levels alone, drives changes in hair growth cycles and determines where and when hair loss occurs 2. Inflammation, oxidative stress and impaired scalp barrier function accelerate follicle miniaturisation and thinning 3. Scalp microbiome composition and sebum dynamics influence inflammatory responses and follicle health 4. Industry impact and potential A deeper biological understanding opens new directions for hair and scalp innovation: Targeted scalp support: Products that improve scalp barrier function and follicle environment rather than masking hair loss. Combination strategies: Addressing inflammation, scalp health and hormonal pathways together. Complementary care: Shampoos and leave-ons that reduce breakage, calm the scalp and support continued use of treatments like minoxidil. Future innovation: Increasing interest in non-hormonal approaches and why certain scalp regions are more susceptible to hair loss. Our position At Sequential, we help brands understand what hair and scalp formulations are doing in real-world conditions. By combining microbiome profiling with molecular, metabolomic and multi-omic analysis, we track changes in scalp health, inflammatory activity and follicle-relevant pathways over time. Drawing on our global database of 50,000+ biological samples, we benchmark formulations across different scalp types and environments, supporting the development of products that promote long-term hair and scalp health. References Redmond, L. et al. (2023). Male pattern hair loss and developmental origins. Exp Dermatol, 32, 1174–1181. Xiao, Y. et al. (2025). Immune and non-immune interactions in androgenetic alopecia. Clin Rev Allergy Immunol, 68. Du, F. et al. (2024). Oxidative stress in hair follicle development. J Cell Mol Med, 28. Polak-Witka, K. et al. (2019). The role of the scalp microbiome in hair follicle biology. Exp Dermatol, 29, 286–294.

Preservation is essential in skincare, ensuring products remain safe and stable throughout use. Without it, water-based formulations are vulnerable to contamination, posing risks to both product performance and consumer health. At the same time, growing awareness of the skin microbiome has raised questions about how preservatives interact with the skin’s natural ecosystem. This has shifted the conversation from simply preserving products to understanding how preservation systems work alongside skin biology. What we know Preservatives prevent the growth of bacteria, yeast and mould in cosmetic products, particularly those containing water, making them essential for product safety and shelf life 1. The skin microbiome is a complex ecosystem that supports barrier function, immune balance and repair processes. In laboratory studies, some preservatives can inhibit both harmful and beneficial skin bacteria, potentially causing microbiome disruption 2. However, human studies using real-world formulations typically show little to no lasting change in microbiome diversity or abundance when products are used as directed 3. Industry impact and potential Preservation is driving a shift towards more considered, biology-led formulation: Barrier-first formulations: Pairing panthenol with other ingredients such as ceramides and fatty acids to support barrier resilience. Microbiome-aware preservation: Designing systems that protect the product while minimising disruption to the skin ecosystem. From safety to balance: Moving beyond antimicrobial strength alone to consider how full formulations interact with skin over time. Alternative preservation strategies: Exploring multifunctional ingredients and formulation approaches that reduce reliance on traditional preservatives. Our position At Sequential, we help brands move beyond single-ingredient thinking by evaluating how preservation systems function within the full formulation. Using microbiome and multi-omic analysis, we generate real-world insight into how products interact with the skin ecosystem. Supported by our global database of 50,000+ samples, we enable the design of preservation strategies that are both effective and aligned with skin biology. References Halla, N. et al. (2018) Cosmetics preservation: A review on present strategies. Molecules, 23( 7): 1571. Pinto, D. et al. (2021) Effect of commonly used cosmetic preservatives on skin resident microflora dynamics. Scientific Reports, 11: 8695. Callejon, S. et al. (2023) Impact of leave-on skin care products on the preservation of skin microbiome. Clinical, Cosmetic and Investigational Dermatology, 16: 2727.

Pigmentation concerns are often treated as surface level issues, yet skin tone and dark spot formation are shaped by complex biological pathways. Traditional approaches tend to focus on single pathways or individual ingredients, but genetics, environment, metabolism and microbial activity all intersect and have impact. Multi-omics offers a more complete way to understand pigmentation by looking at multiple biological layers at once. This includes genes, proteins, metabolites, lipids and the skin microbiome. Bringing these insights together, this multi-omic view is shifting the field away from ingredient-led claims toward system-level insight into why pigmentation behaves differently across individuals and skin tones. What we know Multi-omic research shows that pigmentation outcomes emerge from interactions between genetic regulation, metabolic activity and intracellular signalling, with lipid and metabolite profiles playing a key role in pigmentation issues 1. Genetic, environmental and lifestyle factors interact to shape individual pigmentation responses 2. Since pigmentation pathways interact dynamically, focusing on one mechanism alone often fails to explain variable outcomes across skin tones, populations and environments 3. By integrating molecular, metabolic and microbial data, multi-omic approaches help explain why similar products can perform very differently between individuals 4. Industry impact and potential Multi-omics creates new possibilities for pigment care: Clearer understanding: Showing how and why pigmentation changes, not just whether it does. Better targeting: Designing formulas that target the biological processes most relevant to different pigmentation concerns. Inclusive innovation: Building products based on real biological differences across skin tones and environments, rather than one-size-fits-all averages. Our position At Sequential, we use multi-omic analysis to move pigmentation research beyond single-actives and surface outcomes. By integrating molecular, metabolomic and microbiome data with in-vivo testing, we map how pigmentation pathways respond over time and in real-world conditions. Supported by our 50,000+ sample database, this approach allows brands to develop evidence-led, inclusive pigment solutions grounded in biology rather than broad brightening claims. References Bajpai, V. et al. (2023). Determinants of human pigmentation. Science, 381, eade6289. Jablonski, N. (2021). Evolution of human skin pigmentation. Pigment Cell Melanoma Res, 34, 707–729. Pavan, W. & Sturm, R. (2019). Genetics of human skin and hair pigmentation. Annu Rev Genom Hum Genet, 20. Serre, C. et al. (2018). Regulation of human skin melanogenesis. Int J Cosmet Sci, 40.

Panthenol (pro-vitamin B5) is a widely used yet often underestimated skincare ingredient known for its soothing, hydrating and barrier-repair properties. Commonly found in creams, serums and masks, it is often seen as a supporting ingredient rather than a key active. However, evidence shows that panthenol does far more than basic moisturisation. For sensitive, compromised or post-procedure skin, it plays an important role in restoring comfort, resilience and skin function. As the industry shifts toward barrier health and gentle care, panthenol is increasingly recognised as a key ingredient for long-term skin recovery rather than short-term soothing. What we know Panthenol (provitamin B5) converts into pantothenic acid when applied to the skin and penetrates the outer skin layer, increasing water retention and reducing transepidermal water loss (TEWL) 1. It strengthens the skin barrier by supporting lipid production and new skin cell growth, helping damaged or irritated skin recover more quickly 2. Panthenol also has soothing and anti-inflammatory effects, helping to reduce redness, irritation and UV-related skin sensitivity 3. When used in skincare, 1–5% show consistent improvements in hydration, barrier repair and overall skin comfort 4. Industry impact and potential Panthenol offers clear opportunities for barrier-led, science-driven skincare innovation: Barrier-first formulations: Pairing panthenol with other ingredients such as ceramides and fatty acids to support barrier resilience. Sensitive and post-procedure care: Use in masks, emollients and recovery products for compromised or reactive skin. Synergistic systems: Combining with niacinamide or prebiotics to boost soothing, redness reduction and repair. Next-generation derivatives: Ingredients such as panthenol citrate potential for antioxidant, photoprotective and anti-inflammatory benefits. Our position At Sequential, we combine microbiome profiling with molecular, metabolomic and multi-omic analysis, and can evaluate how panthenol-containing formulations affect hydration, TEWL, lipid balance and skin resilience in real-world use. Leveraging our global database of 50,000+ samples, we support brands in developing evidence based, barrier-focused formulations that prioritise long-term skin health, comfort and repair rather than surface-level soothing claims alone. References Proksch, E. et al. (2017). Topical use of dexpanthenol: a 70th anniversary article. Journal of Dermatological Treatment, 28, 766–773. Gao, M. et al. (2025). Efficacy and safety of a panthenol-enriched mask for skin barrier recovery after facial laser treatment. Journal of Cosmetic Dermatology, 24. Gorski, J. et al. (2020). Dexpanthenol in wound healing after medical and cosmetic interventions. Pharmaceuticals, 13. Camargo, F. et al. (2011). Skin moisturizing effects of panthenol-based formulations. Journal of Cosmetic Science, 62, 361–370.

Bioferments are ingredients created through controlled fermentation, where selected microorganisms break down natural raw materials (e.g. rice or soy) into biologically active components. Although fermentation has long been used in food and medicine, its growing role in skincare reflects increasing demand for ingredients that are both effective and skin-compatible. As bioferments become more common, they are often grouped under a single label despite wide differences in production and skin behaviour, and the effects of fermentation are not always clearly defined. What we know Many bioferments act as postbiotic or prebiotic-like systems, supplying microbial metabolites that may support keratinocyte immunity and favour beneficial skin microbes 1. Fermentation can help enhance formulations’ ability to retain moisture, improving skin hydration and barrier support compared with non-fermented ingredients 2. In vitro and limited clinical studies suggest certain ferments can improve barrier metrics (e.g. hydration) and antioxidant capacity 3. Some bioferments show antimicrobial and anti-inflammatory activity in models, including reduced pro-inflammatory cytokines and inhibition of skin-relevant bacteria 4. Industry impact and potential Bioferments open up a rich area of exploration for skincare, offering both opportunity and challenge: Functional complexity: Single ingredients can deliver multiple bioactive components. Enhanced tolerability: Many bioferments are associated with good tolerability, making them appealing for sensitive or compromised skin. Mechanistic uncertainty: Many cosmetic ferments remain only partially characterised, creating opportunities to better understand how composition links to skin outcomes. Evidence gaps: More research is needed to understand how bioferments influence the microbiome and skin barrier over time. Our position At Sequential, we help brands move from “fermented” as a label to fermentation with purpose. Using microbiome profiling, metabolomics, molecular and multi-omic analysis alongside in-vivo testing, we characterise what bioferments actually contain and how they interact with skin biology over time. By linking composition to function, we provide mechanistic clarity, helping brands identify when fermentation genuinely improves performance, optimise formulations, and make defensible, evidence-led claims grounded in biology rather than buzzwords. References Yang, F. et al. (2025). Biologically active components and skincare benefits of rice fermentation products. Cosmetics, 12, 1–29 Majchrzak, W. et al. (2022). Biological and cosmetic importance of fermented raw materials. Molecules, 27, 4845. Cui, H. et al. (2023). Probiotic ferment lysate lotion improves skin barrier function. Sci Rep, 13, 43336. Nizioł-Łukaszewska, Z. et al. (2025). Apiaceae bioferments as sources of active skincare compounds. Molecules, 30, 983.

The skin lipidome is the complete collection of lipids naturally found within the skin, spanning the stratum corneum, viable epidermis and surface sebum. Often overlooked, lipids play a central role in skin function, regulating hydration, shaping responses to irritation and mediating interactions with the environment. While skincare often focuses on individual ingredients or surface-level effects, beneath this lies a highly organised lipid system that maintains barrier integrity, protects against environmental stressors and supports balance. Understanding the lipidome offers a different way to think about skin, as a system to understand and support. As skincare evolves, this shift is becoming key to moving beyond quick fixes towards more precise, long-term skin health. What we know The stratum corneum is built on a lipid matrix of ceramides, cholesterol and fatty acids that regulates water loss and protects against environmental stressors 1. Sebum adds triglycerides, squalene and wax esters, forming a surface film that supports flexibility and microbial balance 2. Lipids are bioactive. They drive inflammation, immune responses and pigmentation pathways 3. Lipid composition is dynamic, varying by site, age and condition, with small shifts linked to acne, eczema, dryness and ageing 4. Industry impact and potential The skin lipidome enables a shift from generic claims to biology-led innovation: Precision lipid design: Moving beyond simply “adding ceramides” to recreating the lipid profiles and ratios found in healthy skin. From replenishment to regulation: Addressing lipid imbalance and metabolism, rather than just replacing what is missing. Microbiome-aware formulations: Supporting beneficial microbes while limiting conditions that drive dysbiosis. Mechanism-led claims: Using lipidomics to demonstrate how formulations influence hundreds of lipid species. Our position At Sequential, we help brands move beyond surface-level measures of skin function by integrating lipidomics with microbiome and multi-omic analysis. By mapping how formulations shift the skin lipidome in real-world conditions, we enable targeted, evidence-led skincare that works with the skin’s biology. Using our global database of 50,000+ samples, we support the development of formulations that target the biological drivers of skin health, moving beyond short-term effects towards measurable, long-term outcomes. References Bouwstra, J, et al. (2023). The skin barrier: An extraordinary interface with an exceptional lipid organization. Prog Lipid Res, 92, 101252. Siqueira, R, et al. (2025). Skin Lipids and Their Influence on Skin Microbiome and Skin Care. ACS Omega, 10, 28534 - 28546. Nicolaou, A. et al. (2024). Bioactive lipids in the skin barrier mediate its functionality in health and disease. Pharmacol Ther, 260, 108681. Knox, S, et al. (2021). Skin Lipids in Health and Disease: A Review. Chem Phys Lipids, 236, 10505.

“Microbiome-friendly” has become one of skincare's most attractive claims. It suggests science, gentleness, and a product that understands modern skin research. Yet there is an uncomfortable question: what does the seal prove? Where did “microbiome-friendly” certification come from? Most microbiome certifications were developed by private organisations rather than regulators. The best known was launched in 2018 by MyMicrobiome, a German start-up founded around Dr Kristin Neumann. Their purpose is valuable: a standardised way of assessing whether a formulation is unlikely to damage selected skin microorganisms in the laboratory; however, these measures are only part of the picture. What does it test and what does it not test? Certification assesses whether a product is unlikely to disrupt selected skin microorganisms under controlled laboratory conditions. Testing may examine whether the formulation: Preserves beneficial microbes Avoids promoting harmful species Maintains microbial diversity within a defined panel Meets microbiological quality standards It does not typically assess: How the microbiome responds during real-world use Whether microbial changes translate into clinical skin benefits How age, skin type, ethnicity, health and environment influence those responses Why are regulators pushing back on seal-only substantiation? Regulators are raising expectations for how microbiome claims are substantiated. They expect evidence matching the consumer’s interpretation. “Tested to preserve microbial balance” is very different from “restores your skin microbiome”. The stronger the implied benefit, the stronger the evidence required. What does a regulator-defensible microbiome claim look like in 2026? The strongest claim combines multiple layers of evidence: laboratory studies, human microbiome sequencing where appropriate, clinical skin measurements and transparent documentation. Together, these form a weight-of-evidence approach far more robust under scrutiny. Is the seal still worth having? Absolutely. The seal remains a useful signal that a product has undergone independent laboratory assessment, and it builds consumer confidence. The mistake is treating the seal as the destination rather than the starting point. It should sit alongside a broader evidence package, not replace it. What would you put on a claim file if you were audited tomorrow? A defensible claim file links the marketing claim to the evidence behind it: exact claim wording, product details, scientific rationale, testing methods and results, microbiome data, clinical outcomes, safety assessments, and documentation showing the evidence supports the consumer message. The strongest brands will not abandon the seal, but make sure the evidence behind it is stronger than the badge in front of it.