Keratin for hair: The ultimate guide to stronger, shinier hair

Why your hair craves keratin

Every woman knows the feeling: You look in the mirror and instead of shiny, full hair, you see only straw-like, brittle hair, lifeless and lifeless. Split ends, frizz, and breakage tell the story of blow-drying, straightening irons, coloring, and environmental stress. The good news: Your hair is made up of 85-90% keratin, a protein – and you can replenish this protein from the outside.

Keratin isn't a marketing gimmick from the cosmetics industry; it's the fundamental building block of your hair. Understanding how keratin works and how to use it correctly allows you to rebuild even severely damaged hair. This comprehensive guide will tell you everything you need to know about the science behind keratin, which products truly work, and how to create an effective keratin routine.

What exactly is keratin?

Keratin is a fibrous structural protein that is widespread in nature. It forms the main component not only of human hair, but also of nails, the outer layer of skin, as well as horns, feathers, and claws in animals. Keratin's particular strength lies in its molecular structure: long protein chains are linked together by so-called disulfide bridges – sulfur-containing bonds that give hair its elasticity and resilience.

Imagine the structure of hair like a rope: thousands of keratin protein fibers are wound around each other in a spiral, forming the inner structure of each individual hair, the so-called cortex. Surrounding this core is the cuticle – a protective scale layer, also made of keratin. In healthy hair, these scales lie flat and reflect light, resulting in a natural shine.

The problem: Our hair is constantly exposed to damage. Heat from blow-drying and straightening, chemical treatments like coloring and perming, mechanical stress from brushes and hair ties, UV radiation, and pollution – all these factors attack the keratin. The disulfide bonds break, the cuticle becomes rough and raised, and the hair loses its structure. The result: breakage, split ends, frizz, and dull, lifeless hair.

The science: How hydrolyzed keratin works

The difference between keratin and hydrolyzed keratin

When we talk about keratin in hair care products, we usually mean hydrolyzed keratin. The difference is crucial: Native keratin protein is far too large to penetrate the hair structure. It would simply remain on the surface and be rinsed away during the next wash.

Hydrolyzed keratin, on the other hand, has been broken down into smaller peptides and amino acids through an enzymatic or chemical process. These smaller molecules can actually penetrate the hair cortex and "fill in" the damaged areas. Scientists refer to this as "molecular-level repair."

What the research says

An important 2008 study by Secchi investigated the effects of hydrolyzed keratin on damaged hair. The researchers found that keratin peptides significantly improved the mechanical strength of chemically treated hair. The hair exhibited increased tensile strength and reduced breakage.

Further studies by Barba et al. (2010) confirmed that hydrolyzed keratin strengthens hair structure from within. Particularly interesting was the cumulative effect – the more regular the application, the stronger the effect. The researchers observed an improvement in hair elasticity of up to 40% after eight weeks of use.

A study by Fernandes and Cavaco-Paulo (2012) went a step further and showed that keratin peptides not only repair existing damage but also form a preventive protective film that protects the hair from future damage.

The repair mechanism in detail

When you use a keratin shampoo or keratin conditioner, the following happens at a microscopic level:

The hydrolyzed keratin peptides are absorbed by the hair and migrate through the damaged cuticle into the cortex. There, they fill the cavities created by the loss of the body's own keratin. They form new bonds with the existing proteins, literally filling the "holes" in the hair structure.

At the same time, some of the keratin settles on the outer cuticle layer, smoothing it. The previously raised cuticles are flattened, the hair reflects more light, and appears shinier. This smoothing effect also significantly reduces frizz, as the closed cuticle absorbs less moisture from the air.

The 7 most important benefits of keratin for your hair

1. Repairing hair damage

The most obvious benefit: Keratin repairs damaged hair from the inside out. Whether caused by heat styling, chemical treatments, or mechanical stress, hydrolyzed keratin can partially restore the lost protein structure. The hair becomes stronger and more resilient again.

2. Reduction of hair breakage

Hair breakage occurs when the hair's internal structure is so weakened that it can no longer withstand mechanical stress. Keratin strengthens this structure and makes the hair more elastic. Studies show that regular keratin treatments can reduce hair breakage by up to 80%.

3. Visibly more shine

When the cuticle is damaged, the hair reflects light unevenly and appears dull. Keratin smooths the cuticle and ensures that the scales lie flat again. The result: intense, natural shine that seems to come from within.

4. Frizz control

Frizz occurs when raised cuticle layers absorb moisture from the air, causing the hair to swell. Keratin seals the cuticle, forming a protective barrier against humidity. Even in humid weather, the hair remains smooth and manageable.

5. More volume and fullness

It sounds paradoxical: How can a protein that smooths hair also add volume? The trick lies in strengthening the hair structure. Healthy, strong hair has more body and doesn't fall flat as easily. Fine hair, in particular, benefits enormously, as it gains substance from keratin without being weighed down.

6. Protection from heat and the environment

Keratin forms a protective film around each individual hair. This film acts like a heat shield during blow-drying and straightening, protecting against UV radiation and environmental pollutants. This prevents further damage.

7. Improved combability

Damaged hair tangles easily and is prone to knots. The smoothing effect of keratin ensures that combs and brushes glide effortlessly through it. This not only reduces styling time but also the mechanical stress caused by aggressive combing.

When your hair needs keratin: The warning signs

Not all hair needs intensive keratin treatment. But if you recognize one or more of these warning signs, it's time to take action:

Visible split ends: Split ends are a sure sign that the hair structure is damaged. While keratin can't "glue" existing split ends, it can prevent them from traveling further up the hair shaft.

Increased hair breakage: If you lose an excessive amount of hair when combing or after showering, and the hair breaks off in the middle of the length (not at the root), this is a sign of weakened hair structure.

Straw-like, rough feeling: Healthy hair feels silky and smooth. If your hair feels rough and dry, this is often due to a damaged cuticle layer.

Dull, matte shine: When even freshly washed hair looks lifeless and lackluster, the damaged cuticle no longer reflects the light properly.

Uncontrollable frizz: Especially in humid conditions, the hair curls up and cannot be tamed – a classic sign of an open cuticle layer.

Dyeing or bleaching: Chemical treatments severely damage the hair structure. Keratin care is especially important after every coloring.

Regular heat styling: Hairdryers, straighteners, and curling irons at high temperatures destroy the disulfide bonds in keratin. Those who style their hair daily should regularly replenish their keratin.

The perfect keratin routine: A 3-step system

For optimal results, we recommend a coordinated keratin system consisting of three products that work synergistically:

Step 1: Cleansing with the Keratin Volume Boost Shampoo

The foundation of any good hair care routine is proper cleansing. Our Keratin Volume Boost Shampoo is designed to thoroughly cleanse the hair without drying it out – while simultaneously delivering the first dose of keratin.

What makes this shampoo special?

The formula combines mild, sulfate-free surfactants with hydrolyzed keratin. While the shampoo removes sebum, styling residue, and environmental pollutants, the keratin begins to penetrate the hair structure. This makes cleansing the first step in hair care.

The star ingredients in the shampoo:

Hydrolyzed keratin: Penetrates the hair structure during washing, filling gaps and strengthening from within.

Caffeine: Stimulates the scalp and promotes blood circulation. Well-circulated hair follicles produce stronger hair.

Peppermint oil & menthol: Refresh the scalp with an invigorating cooling effect and have an antibacterial effect.

Rosemary oil: Proven to promote hair growth. A study by Panahi et al. (2015) showed that rosemary oil can be just as effective as minoxidil.

Sodium PCA & Zinc PCA: Form a hydration complex that binds moisture and keeps the scalp in balance.

Chanterelle extract: Rich in trace elements and B vitamins that nourish the hair.

Application: Massage a hazelnut-sized amount into damp hair, lather, and gently work into the scalp and lengths. Rinse thoroughly. Repeat the process for heavily soiled hair or hair with a lot of styling products.

Step 2: Intensive care with the Keratin Volume Boost Conditioner

After cleansing, hair is particularly receptive to conditioning agents. The Keratin Volume Boost Conditioner makes optimal use of this moment, delivering a concentrated dose of keratin plus nourishing oils.

What makes this conditioner special?

The rich formula is designed to provide intensive care without weighing hair down. The key lies in the balance: while hydrolyzed keratin repairs the inner structure, light oils smooth the outer cuticle layer – without leaving a greasy residue.

The star ingredients in the conditioner:

Hydrolyzed keratin: Continues the repair work started by the shampoo. The longer application time allows for deeper penetration.

Organic coconut oil: The only oil proven to penetrate the hair structure. It reduces protein loss and makes hair supple from within.

Organic avocado oil: Rich in oleic acid and vitamin E. Intensely nourishes dry hair and gives it a silky shine.

Organic almond oil: Light and quickly absorbed. Smoothes the hair cuticle and makes hair easier to comb.

Nettle extract: Traditionally used to strengthen hair roots. Rich in silica, iron, and B vitamins.

Chanterelle extract: Provides trace elements and antioxidants for healthy hair.

Vitamin E (Tocopherol): As an antioxidant, it protects against free radicals and preserves hair color.

Application: After shampooing, squeeze out excess water. Work a walnut-sized amount into the lengths and ends of your hair, avoiding the scalp. Leave on for 2-3 minutes (longer for severely damaged hair), then rinse thoroughly.

Step 3: Protection & Finish with the Keratin Shine Leave-In Hair Mist

The Keratin Shine Leave-In Hair Mist is the crowning finale of your keratin routine – and at the same time your daily companion for well-groomed, shiny hair.

What makes this crap so special?

As a leave-in product, the mist stays in the hair and works its magic all day long. The lightweight spray formula won't weigh hair down and can even be used on dry hair throughout the day. Ideal for anyone who needs a quick boost of freshness.

The star ingredients in the leave-in mist:

Hydrolyzed keratin: Remains on the hair and forms a protective film. Continuously repairs and protects against mechanical stress.

Lactic acid: A gentle AHA that optimizes the hair's pH level. This closes the cuticle layer and makes the hair shine more intensely.

Red algae extract (Furcellaria lumbricalis): Forms an invisible film that locks in moisture and protects against heat. Ideal as a natural heat protectant before styling.

Essential oils from citrus fruits and rose geranium: They impart a fresh, elegant fragrance and also have a nourishing effect.

Application: Spray onto towel-dried hair and distribute with your fingers or a wide-tooth comb. Do not rinse. Then style as usual. Can also be used on dry hair to tame frizz or refresh shine.

At-home keratin treatment vs. salon: Which is better?

Salon treatments: The facts

Professional keratin treatments in salons – often called "Brazilian Blowout" or "Keratin Smoothing Treatment" – promise smooth, frizz-free hair for several months. The keratin is sealed into the hair using heat.

However, there are significant concerns: Many of these treatments contain formaldehyde or formaldehyde-releasing substances, which release toxic fumes when heated. The U.S. Occupational Safety and Health Administration (OSHA) has repeatedly warned of the health risks. Symptoms range from eye and respiratory irritation to an increased risk of cancer with regular exposure.

Furthermore, salon treatments are expensive (€200-500 per session), time-consuming (3-5 hours) and need to be repeated every few months.

Keratin hair care for home use: The smart alternative

High-quality keratin shampoos, conditioners, and leave-in products offer a safe, effective, and cost-efficient alternative. The advantages:

Safety: No formaldehyde or other harmful chemicals. COSMOS-certified products guarantee strict ingredient standards.

Continuous care: Instead of an intensive treatment every few months, your hair receives a dose of keratin with every wash. The effect builds up cumulatively.

Flexibility: You decide how intensively you care for your hair. Daily for severely damaged hair, 2-3 times a week for healthy hair.

Cost efficiency: A home keratin routine costs a fraction of a salon treatment and lasts significantly longer.

Natural result: The hair is strengthened and smoothed, but retains its natural movement and volume.

Frequently asked questions about keratin

Is keratin suitable for all hair types?

Yes! Keratin is a natural component of all hair, regardless of hair type or structure. Fine hair benefits from more substance and body, thick hair becomes smoother and easier to manage, curly hair gets defined, frizz-free curls, and straight hair gains more shine and volume.

Is it possible to use too much keratin?

Theoretically, yes – this is referred to as "protein excess." The symptoms: Hair becomes hard, brittle, and breaks more easily. However, this is practically impossible with high-quality keratin care products like shampoos and conditioners, as they only contain a moderate amount of keratin. Problems arise more with the excessive use of concentrated protein treatments.

Our tip: Pay attention to the balance between protein (keratin) and moisture. The Keratin Volume Boost series is already optimally formulated and contains not only keratin but also moisturizing ingredients like sodium PCA and nourishing oils.

How quickly will I see results?

You'll often notice an immediate improvement in shine and manageability after just one use. For lasting improvement in hair structure, you should use keratin treatments regularly for at least 4-6 weeks. The best results are seen after about 8 weeks of continuous use.

Is keratin treatment suitable for color-treated hair?

Absolutely – highly recommended! Hair coloring damages the hair structure and makes it porous. Keratin repairs this damage and helps the color last longer. The sealed cuticle layer prevents color pigments from washing out.

Can I use keratin products together with other hair care products?

Yes, keratin treatments can easily be integrated into any routine. Particularly good partners are moisturizing masks (alternating with keratin treatments), heat protectant sprays, natural oils for the ends, and leave-in conditioners.

You should avoid strongly drying products such as dry shampoo with daily use or aggressive styling products with a lot of alcohol.

Is keratin in hair care products vegan?

It depends on the source. Traditionally, keratin is derived from animal sources (feathers, wool, hooves). However, there are also plant-based alternatives derived from wheat protein or other plant sources that have similar properties. Our Keratin Volume Boost series is completely vegan and cruelty-free.

Additional tips for strong, shiny hair

The correct washing technique

How you wash your hair makes a big difference. Use lukewarm, not hot, water – heat opens the hair cuticle and allows moisture to escape. Gently massage the shampoo into your scalp without scratching. The lengths will be cleaned automatically when you rinse. With conditioner, it's the opposite: focus on the lengths and ends, avoiding your scalp.

Dry gently

Rubbing is a no-go! Wet hair is especially fragile. Gently squeeze out excess water with a microfiber towel or an old t-shirt. If possible, let your hair air dry. If you must use a hairdryer, use the lowest heat setting and hold it at least 15 cm away.

Heat protection is mandatory

Always apply a heat protectant before using a flat iron, curling iron, or hot hairdryer. The Keratin Shine Leave-In Hair Mist offers natural heat protection thanks to its red algae extract.

Trim the ends regularly

Even the best keratin treatment cannot repair existing split ends. Get your ends trimmed every 8-12 weeks to prevent split ends from traveling upwards.

Nourish from within

Beautiful hair starts from within. Ensure you eat a protein-rich diet with sufficient biotin (eggs, nuts, whole grains), iron (green leafy vegetables, legumes), and omega-3 fatty acids (oily fish, flaxseeds). Don't forget to drink plenty of water!

Your journey to stronger hair starts now

Keratin isn't a miracle cure – but it's the closest thing you can get. As a fundamental building block of your hair, added keratin can repair damage, strengthen the structure, and restore your hair's natural shine.

With the right routine – cleansing, conditioning, and protection – you give your hair exactly what it needs with every wash. The results speak for themselves: less breakage, more shine, easier combing, and finally, hair that feels the way it's supposed to look.

Ready for your keratin transformation?

Start with the complete Keratin Volume Boost System :

→ Keratin Volume Boost Shampoo – The powerful cleanser (€39.90)

→ Keratin Volume Boost Conditioner – Intensive Care (€39.90)

→ Keratin Shine Leave-In Hair Mist – Daily Protection (€42.90)

Scientific sources

1. Secchi, G. (2008). Role of protein in cosmetics. Clinics in Dermatology , 26(4), 321-325.
2. Barba, C., et al. (2010). Restoring important hair properties with wool keratin proteins and peptides. Fibers and Polymers , 11(7), 1055-1061.
3. Fernandes, M. M., & Cavaco-Paulo, A. (2012). Protein disulphide isomerase-mediated grafting of cysteine-containing peptides onto over-bleached hair. Biocatalysis and Biotransformation , 30(1), 10-19.
4. Panahi, Y., et al. (2015). Rosemary oil vs minoxidil 2% for the treatment of androgenetic alopecia: a randomized comparative trial. Skinmed , 13(1), 15-21.
5. Rele, AS, & Mohile, R.B. (2003). Effect of mineral oil, sunflower oil, and coconut oil on prevention of hair damage. Journal of Cosmetic Science , 54(2), 175-192.
6. Bolduc, C., & Bharat, R. (2012). Hair biology and its implications for cosmetic enhancement. Dermatologic Clinics , 30(2), 275-287.