Well-groomed, beautiful, and strong nails share a not-so-secret ingredient that nail pros swear by: keratin at its best! This natural protein, a key component of the nail matrix, plays a vital role in the appearance and strength of your nails. But keratin is also delicate and can be easily affected by external aggressors, overly frequent manicures, or even health issues. Here’s everything you need to know to protect and maintain healthy keratin levels in your nails!
What is nail keratin?
An essential protein
Keratin is a fibrous structural protein naturally found in your hair, skin... and nails! Rich in sulphur and amino acids, it makes up about 90% of the nail plate.
It’s within the nail matrix that keratin is produced. As the cells mature, keratin fibres accumulate and harden through the keratinisation process, enabling healthy, continuous nail growth. This results in the formation of three interlinked layers that make up the nail plate:
- A deep layer at the nail bed, where keratinisation begins,
- A middle layer made of soft cells,
- A surface layer composed of hard cells.
Water, lipids, and minerals (mainly sulphur, iron, and zinc) are also essential for high-quality keratin. When keratinisation functions properly, the nail surface is smooth, shiny, and resilient.
Your nails are made up of 90% natural keratin. Treat them with care!
What does keratin do?
Keratin plays a fundamental role in nail health. It ensures:
- Nail structure: keratin fibres give nails their natural shape and rigidity.
- Healthy growth: strong keratin helps nails grow consistently and without flaws.
- Matrix protection: the outer keratin layer shields against external damage (impacts, humidity, friction).
- A smooth base for polish: quality keratin provides better adherence for both classic and gel polishes.
In short, healthy keratin is crucial for nail strength and beauty. But as keratin sits at the interface between the internal matrix and external environment, it’s vulnerable to everything happening both inside and outside your body.
With healthy keratin, your polish lasts longer!
When and how to strengthen nail keratin?
Signs of weakened keratin
If keratin production slows down or the layers formed are of poor quality, it inevitably shows on your nails. These signs can appear gradually as the nail grows out, and may include:
- Soft or brittle nails
- Ridged nails
- Split or peeling nails
- Nails that struggle to grow
These signs may stem from various internal and external factors:
💦 Frequent exposure to water or cleaning products.
💅 Overly frequent polish application or aggressive manicure techniques.
🍽️ Nutritional deficiencies in minerals and essential vitamins that support nail growth.
🧘 Health issues or emotional stress that disrupt internal balance.
When that happens, it’s time to adopt a targeted routine to revive keratin production and restore healthy, strong nails.
How to boost your keratin levels
Kératine Booster: the miracle product for stronger nails
Better than traditional strengthening polish, the Kératine Booster is a hardening treatment that instantly strengthens soft nails and densifies the nail plate by stimulating natural keratin production. Its effectiveness comes from a 96.5% bio-sourced, biomimetic formula packed with:
- Plant-based keratin (10%) to deeply nourish and strengthen fragile nails
- Biotin (Vitamin B8) to stimulate keratin production and reduce splitting and breakage
- AHAs and gluconolactone to support cell renewal and maintain hydration
- Silicon to improve nail flexibility and boost moisture retention
- Vitamin C for antioxidant protection against environmental stress
👉 How to use it: For up to 7 days, apply Kératine Booster to bare nails 1 to 3 times daily for an intensive treatment. Its lightweight texture absorbs instantly with no greasy or sticky finish.
Clinical tests carried out under dermatological supervision on a panel of 25 people confirmed visible results from the first few days:
💎 85% reported harder nails
👌 81% noticed fewer split nails
Over 80% of testers saw stronger, healthier nails after a Kératine Booster treatment.
Day & Night routine: a repairing duo
For round-the-clock care, go for the Kératine Booster & S.O.S. Mask duo — combining an innovative daytime treatment to repair the nail structure and an intensive overnight treatment to hydrate damaged nails.
👉 How to use: For 1 week, apply Kératine Booster to bare nails 1 to 3 times a day and let it dry. Then, 2 to 3 nights a week, apply a generous layer of S.O.S. Mask to bare nails. Allow to air-dry and remove the next morning by peeling it off or rinsing with soapy water.
Boost your keratin levels all day long with the Day & Night Duo.
Top tips for healthy keratin
High-quality keratin also relies on a few simple everyday habits:
- Hydrate and nourish your nails using plant-based oils like sweet almond or castor oil. Our Huile Verte is a blend of six botanical oils — the perfect daily treatment for nails and cuticles.
- Protect your nails during household chores or when handling chemicals. Avoid prolonged exposure to water, especially hot water.
- Eat a balanced diet with foods rich in biotin (eggs, almonds, brewer's yeast, avocado), sulphur-rich amino acids (meat, fish, lentils), and zinc, iron, and silicon (seeds, green veg, dried fruit).
- Opt for gentle, long-lasting manicures using high-quality, bio-sourced formulas like our Green™ polishes and Green Flash™ range if you're a gel polish lover. Avoid back-to-back gel polish applications, and always use an acetone-free remover like our Gentle Green Flash™ Remover.
Protect your keratin by following a gentle, nail-friendly manicure routine.
Keratin fibres are the backbone of your nails — the secret to their strength and beauty. To avoid the common issues caused by weakened keratin, the answer is often simple: prioritise hydration, targeted treatments, and manicure routines that respect your nail’s natural structure. So let's nail it 🪄
