Proteins & peptides
Silk proteins
Also listed as silk amino acids, hydrolyzed silk, sericin, silk protein
Proteins from silkworm silk that film the hair and hold moisture, adding softness and shine. A conditioning effect only.
Limited evidenceTypical strength: Usually under 1% in shampoos, conditioners and styling products
What it is
Silk proteins (fibroin broken into amino acids or small peptides, and sericin, the silk 'gum') attract water and form a light film on the hair. The result is softer, glossier hair that combs more easily until the next wash.
How strong is the evidence?
Limited evidenceSupport comes from ingredient-maker lab tests of gloss, moisture and combing. No trials show effects on hair growth or long-term hair health.
What it's used for, checked
Softer, shinier hair
Holds upTemporary conditioning effect.
Strengthens or repairs hair
UnprovenCoating, not repair.
Works well with
- keratin
- quinoa-protein
Who should be careful
- Very low risk; allergy to silk proteins is rare.