Frizz

Hair that puffs up the moment the air gets humid.

Frizz is lifted cuticle plus humidity: water gets into the fibre unevenly and strands swell and separate. The fix is smoother cuticles, sealed moisture and the right amount of humectant for your weather.

What is happening

Each hair is wrapped in overlapping cuticle scales. When those scales are raised, from heat, colour, rough towel-drying or simply a high-porosity pattern, water vapour from the air gets in and the fibre swells. Neighbouring strands swell by different amounts, so they stop lying together and the surface looks fuzzy.

Humectants complicate this. Glycerin and similar ingredients pull water towards the hair. In moderate humidity that is moisture; in very humid air it is more swelling, which is why a product that works in winter can frizz you in August.

What helps

  1. 1. Smooth the cuticleA light surface oil such as argan or jojoba, applied to damp hair, helps scales lie flat and lowers friction between strands.
  2. 2. Seal after moistureOn high-porosity hair, a leave-in followed by a sealing oil or butter keeps water in the fibre so the air has less to add.
  3. 3. Match humectants to the weatherKeep glycerin low in humid climates; lean on panthenol and film-formers like flaxseed gel for definition instead.
  4. 4. Cleanse gentlySulfate-free cleansers such as decyl glucoside strip fewer of the hair's own lipids, so the cuticle stays smoother between washes.

Ingredients to look for

Worth avoiding

  • Rough towel-drying (use a T-shirt or microfibre and squeeze)
  • High heat without protection
  • Heavy glycerin products on humid days
Read nextHair porosity, demystified: what your hair is actually telling you

Educational only, not medical advice. Persistent scalp irritation, sudden hair loss or unexplained breakage warrant a visit to a dermatologist. Written by Cosmixxology R&D.