Behind the breakthrough: Your KeraBio™ K31 hair bond builder questions answered

To address this need for deeper understanding and provide essential education, I’ve asked our experts - Frederic de-Baene, Farahdia Edouard and Mike Hindley, to answer the most frequently asked questions about KeraBio K31 and share their expert insights. 

The KeraBio K31 science: Q&A

Does keratin vary across hair types?

Hair keratin is structurally similar across all hair types and ethnicities. While some genetic variations can influence hair texture and type by affecting the levels or proportions of different keratins, the overall structure and function of keratin remains largely consistent. Proteomic analysis, however, has shown that depending on the type of damage, certain keratin sequences may be more susceptible to loss in hair from different ethnicities. 

What do the acronyms and the numbers in the INCI name mean?

(Hydrolyzed sr-(Tripeptide-137 Hexapeptide-40 sh-Polypeptide-184 sh-Polypeptide-146))

• Each cosmetic ingredient has one official INCI name, assigned by the Personal Care Products Council (PCPC), and this must follow strict naming conventions. 
• The prefix “sr” (synthetic recombinant) indicates that the gene sequences were synthesized and the peptide is produced via recombinant biotechnology.
• The prefix “sh” (synthetic human) denotes that the gene sequence for that peptide is inspired by human genetics, though an identical copy has been synthesised. 
• The numbers (137, 40, 184, 146) are assigned sequentially and do not reflect the size or structure of the peptides.
• The peptide known as “sh-Polypeptide-146” corresponds to keratin 31 which makes up the majority (over 90%) of the overall protein sequence in KeraBio K31.
• The other peptides in the INCI are minor components resulting from the biotechnology expression process. 

If KeraBio K31 is a hydrolysed keratin, why doesn’t the INCI name include ‘Hydrolysed Keratin’?

When a protein such as keratin is extracted directly from natural animal sources, it carries the common protein name “keratin” in the INCI, as determined by the PCPC. This can be further hydrolysed, or otherwise chemically modified, but the word “keratin” would still appear. However, when a protein or peptide is produced via biotechnology or synthetic methods, as is the case for KeraBio K31, the naming reflects the production process and peptide structure rather than original protein the material is inspired by. 

Recombinant peptides are therefore named using the conventions described above by the PCPC. In short, whilst technically speaking KeraBio K31 does contain hydrolysed keratin amino acids sequences, its INCI reflects its biotech origin, rather than its keratin identity.

So, is KeraBio K31 of human origin?

KeraBio K31 is biologically inspired by human genetics, but the active peptide is entirely produced by a microorganism using synthetic recombinant technology. No human tissue is involved.

Is KeraBio K31 a GMO, or does it contain GMOs (Genetically Modified Organism)?

No, KeraBio K31 is not a GMO. Although microorganisms are part of the fermentation process, rigorous downstream processing removes all cellular components, ensuring the final peptide is completely free of GMOs.

How does KeraBio K31 repair hair?

Think of it as an internal scaffold. The biomimetic peptide integrates deep into the hair fibre cortex to recharge compromised keratin, significantly strengthening the hair's internal architecture.

So, what types of bonds are formed?

KeraBio K31 forms a variety of non-covalent bonds that mimic natural keratin interactions:

• Ionic interactions between charged residues
• Hydrophobic interactions with non-polar keratin regions
• Hydrogen bonds with adjacent keratin chains

These multi-faceted interactions work together to enhance the hair fibre’s structural cohesion. Our testing substantiates these bonding interactions, confirming that KeraBio K31 effectively integrates into the hair’s keratin network. 

While covalent disulfide bonds are often highlighted in hair repair, popularised by brands such as Olaplex, they are challenging to directly prove and are not necessarily the strongest contributors to hair strength. Insights from TRI’s Dr. Paul Cornwell illustrate why multiple bond types matter: although disulfide bonds are covalent, they are relatively weak and can spontaneously break and reform. Ionic (salt) bonds are actually stronger, requiring more energy to break, while hydrogen bonds are individually weaker but extremely abundant in hair. The weakest interactions are van der Waals forces (hydrophobic interactions), which, though individually weak, contribute to overall hair cohesion because of their sheer number. 

In conclusion, it’s the combination of bond strength and abundance that determines overall hair integrity. You can hear more on this topic from Paul and Mike in our webinar Unlocking the Secrets of the Bond Building Market.

KeraBio K31 leverages this understanding, creating multiple types of bonds that collectively repair and recharge keratin, supporting the hair’s natural resilience at the molecular level.

Will repeated use cause protein “build-up”?

Keratin (and proteins in general) are known to increase in deposition after multiple applications, which is the mechanism that delivers cumulative benefits to hair. However, this effect naturally plateaus at normal application concentrations. As KeraBio K31 is highly potent, if some stiffness is experienced in a given formulation, the solution is simple: KeraBio K31 is effective at active levels as low as 0.05%, allowing formulators to easily decrease the dosage to balance the repair performance with the desired hair feel.

How does KeraBio K31 compare to traditional keratin?

What does KeraBio K31 look like, and how does it appear in a formulation?

These photos show the ingredient itself in a glass vial, and within a formulation - an emulsion system using KeraBio K31 at the highest 10% w/w use level.