Skip to main content

Active ingredient

Keratin

INCI · Hydrolyzed Keratin

Hydrolyzed keratin is a protein fragment used in haircare to deposit a temporary reparative film along damaged cuticles. It binds to areas of cuticle erosion, smooths the hair-shaft surface, and improves combability and shine. Pairs broadly with most actives. No major conflicts.

Last reviewed by BIOSAR Scientific Team, PharmD, Cosmetic Chemistry, Pharmacy practice on .

Pregnancy and breastfeeding

No specific caution is known for cosmetic use during pregnancy or breastfeeding. If you are unsure, ask your doctor or pharmacist.

Topical hydrolyzed keratin is considered safe during pregnancy and lactation per Mother to Baby. Note: in-salon keratin smoothing services that release formaldehyde are a separate concern and are typically avoided in pregnancy; this safety note covers cosmetic-grade hydrolyzed keratin only.

Mechanism in detail

What Keratin does

The structural protein hair is made of. It forms a smoothing film along the fiber, filling the look of damaged, roughened areas so hair reads smoother, stronger and more even from root to tip.

Evidence

What the research says

  • +18.6%Lab test: keratin peptides strengthened relaxed hair

    In lab tests on chemically relaxed, very curly hair soaked 24 hours in keratin solutions, a mid-weight keratin peptide raised the force needed to break a fibre by 18.6% versus relaxed hair soaked in water. The smallest peptide did not help.

    Read the study

    Int J Cosmet Sci 2020 (Malinauskyte et al.)

Where it helps

Concerns Keratin addresses

  • Hair Loss

    For the months you have been finding more hair on the pillow than the comb. For the part line that has slowly widened. For the new mother, the man at the temple recession, the woman watching her ponytail thin — hair loss is a quiet anxiety that most people carry alone for too long before they ask anyone. The Hairmical range is built around the actives that the dermatology and trichology literature considers most defensible for visible shedding: Procapil's three-mechanism complex, caffeine for follicular microcirculation, biotinyl-tripeptide for follicle anchoring. Topical actives work on the follicle's clock — give them 4 to 8 weeks of consistent use for visible improvement, and months for a full growth cycle.

From the BIOSAR catalog

Products formulated with Keratin

Next ingredientLactic Acid