Biologique Recherche's Global VP of Research Answers Your Skincare Questions
The Group Chat (you!) asked, Dr. Hélène Huguet answered.
Today’s letter is in partnership with our friends at Biologique Recherche.
If you’ve been reading for a while, you already know Biologique Recherche lives in my bathroom and my recommendations in roughly equal measure. The Lotion P50 has been a fixture of mine for years. The Masque VIP O2 had a real resurgence in our chat last year, and deservedly so. This isn’t a brand I’m meeting for the first time because a partnership came attached. It’s one I live with every day.
Which is exactly why I wanted to bring you someone who can answer the questions I can’t! Dr. Hélène Huguet is the brand’s global VP of research and development, a PharmD and PhD who has spent her career on formulation and drug delivery. She is the person actually deciding what goes in the bottle — NBD. Having direct access to her is rare, so a few months ago, I opened the floor to you to ask her whatever you wanted.
For my own questions, I went straight for the new new: Crème M.E.C., and why a cream built to reinforce the entire extracellular matrix is a different animal than the hundredth collagen cream. You asked about the barrier and how to rebuild it once it’s compromised, the mistakes most of us are making right now, what’s actually overhyped, how the under-eye should change with age, and what a real over-40 routine requires — and Dr. Huguet answered. Let’s get into it.
“Why do so many skincare and makeup brands include ingredients like hyaluronic acid or niacinamide in nearly every product? Are these ingredients truly universal, or can they be unsuitable for some skin types?” - Tehryn, Substack Chat
Dr. Hélène Huguet: Yes, these do seem to be everywhere! Brands widely use hyaluronic acid and niacinamide because they target fundamental skin functions with well-documented efficacy supported by a strong body of scientific and medical literature. Hyaluronic acid not only improves hydration and reduces TEWL (loss of water through a weak skin barrier), but also contributes to skin elasticity, extracellular matrix organization, etc., with biological effects that vary depending on molecular weight. Niacinamide is extensively studied for its soothing properties and its ability to reduce hyperpigmentation. Their broad tolerability explains their widespread use, but they are not universally applicable: efficacy and tolerance depend on formulation parameters, sourcing, and purity, which can influence clinical outcomes.
These ingredients are not positioned as standalone “hero actives” but as supportive components within a broader, synergistic formulation strategy. Active ingredients are carefully curated; we use ultra-pure niacinamide, and we integrate multiple forms of hyaluronic acid to support complementary skin functions at different levels.
“What exactly is the skin barrier, and how can it be repaired once compromised?” - Emily C., Substack Chat
HH: The skin barrier refers to the functional integrity of the stratum corneum, an organized lipid matrix (ceramides, cholesterol, fatty acids) surrounding corneocytes that regulates water flux and protects against external stressors. In cosmetics, “repair” focuses on restoring this lipid architecture, reducing TEWL with film-forming agents, and supporting endogenous synthesis pathways in the outermost layer of the skin. The objective is to re-establish barrier cohesion and functionality through formulation-driven equilibrium.
If you have highly reactive skin that requires extra care, there are creams specifically developed for your skin type, like the Toleskin cream and mask. These sterile formulations are designed to support barrier recovery while minimizing exposure to potential irritants, ensuring optimal tolerance and helping restore skin integrity in compromised conditions.
“How should skincare for the under-eye area evolve as we age?” - Dina Keilany, Substack Chat
HH: Skincare for the under-eye area must first differentiate between distinct conditions: blue (vascular), brown (pigmented), or hollow (structural) dark circles, as each involves different mechanisms. With age, the anatomy itself evolves: there is fat pad displacement, ligament laxity, and muscle changes. From a cosmetic standpoint, care should focus on what remains modifiable: supporting barrier function, improving hydration, enhancing dermal matrix quality, and optimizing the appearance of microcirculation. In that sense, skincare can improve skin quality and visual fatigue.
Fortunately, there are a variety of textures and formats available that can target a multitude of undereye concerns: “Sérums Authentiques”, to creams, and our highly effective eye patches (“patchs défatiguants”), each designed to respond precisely to specific under-eye concerns while ensuring high tolerance for this particularly fragile area.
“For people over 40 who prefer a minimal routine, what are the absolute skincare essentials?” - Mariam, Substack Chat
HH: Skin experts consistently emphasize a few non-negotiable pillars: daily photoprotection, the primary factor in extrinsic aging, and maintenance of hydration and barrier integrity to limit TEWL (transepidermal water loss) and preserve skin function. As underlying imbalances vary significantly between individuals, even a minimal routine should be grounded in a skin diagnosis.
Within this framework, a curated selection from our nearly 90 face skincare products allows us to focus on essential, high-performance formulas, our best sellers, chosen for their proven efficacy and functional relevance. The approach is not to multiply products, but to select, with precision, those that address the skin’s dominant needs while maintaining long-term balance. This translates into a curated home protocol built on essentials: within a very extensive range, the following is one example of a targeted selection among many possible combinations.
To start your routine, I recommend a gentle yet effective cleanse using one of our cleansing milks; for instance, Lait VIP O2 is particularly suited to urban environments, combining antipollution and oxygenating properties through our patented oxygenating complex. Skin preparation continues with one of our five iconic Lotion P50 formulas, ensuring controlled daily exfoliation and optimal receptivity to subsequent treatments.
Targeted correction is then achieved through Sérums Authentiques. In the context of the 40s, formulas addressing the root mechanisms of aging are particularly relevant, such as Sérum Progeskin, which targets cellular senescence- one of the key drivers of skin aging- and Sérum Spectral, which supports skin resilience to light-induced stress: another major contributor to aging. Applied daily, they help the skin become both stronger and visibly improved.
Finally, a cream, such as Crème M.E.C., helps maintain hydration while supporting the overall integrity of the extracellular matrix, beyond targeting collagen alone, thereby improving density, contour, and overall skin quality over time.
“Beyond P50, which Biologique Recherche product do you consider essential for achieving healthy, hydrated, glowing skin?” - Remy LeMaire, Substack Chat
HH: This is a great question, and it is difficult to point to a single product as the key to healthy skin, without overlooking the importance of a tailored routine, which remains essential for truly healthy-looking, hydrated, glowing skin. Beyond Lotions P50, formulas that improve overall skin function are key. For example, Sérum Spectral supports the skin’s ability to manage light-induced stress, helping restore radiance and complexion uniformity. Masque VIP O2 and Crème VIP O2 enhance oxygenation and energy production, which are directly linked to a fresher, more luminous appearance. Finally, a restructuring formula like Crème M.E.C. helps reinforce extracellular matrix integrity, supporting hydration, density, oval and overall skin quality.
