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Hairmetry

Encyclopedia

Every molecule that touches your hair

From proven medicines to kitchen-cupboard oils, with the studies behind each one.

10 entries

A

  • styling polymer

    Acrylates copolymer

    A family of acrylic polymers that thicken styling gels and dry to a hard, clear film for strong hold.

  • chemical treatment

    Ammonium thioglycolate

    The classic reducing agent in perms and thio relaxers; it breaks hair's disulfide bonds so the shape can change, with some loss each time.

C

  • styling polymer

    Carbomer

    A cross-linked polyacrylic acid that turns watery formulas into clear gels; in hair gels it is mainly the thickener, not the hold agent.

  • drug with hair side effects

    Chemotherapy hair changes ("chemo curls")

    Hair often regrows curlier, softer or a different colour after chemotherapy, but nobody has measured how often; what is better documented is that permanent thin regrowth is more common than once believed.

E

  • drug with hair side effects

    EGFR inhibitors (erlotinib, cetuximab)

    Cancer drugs that block the EGF receptor can make eyelashes grow abnormally long and curly, and scalp hair curly or brittle, all reversing after the drug stops.

F

  • botanical

    Flaxseed gel

    A homemade or commercial gel of boiled flax seeds, popular as a natural curl definer, with no published study on it as a hair styler.

I

S

  • surfactant

    Sodium cocoyl glutamate

    An amino-acid-based cleanser that was among the best-tolerated surfactants in a 105-patient patch-test study, with no scalp or hair trials yet.

  • surfactant

    Sodium cocoyl isethionate

    A mild anionic cleanser, the basis of many syndet bars, with good lab evidence of being gentle on the skin barrier and growing use in sulfate-free shampoos and shampoo bars.

  • chemical treatment

    Sodium hydroxide and guanidine relaxers (lye and no-lye)

    Chemical relaxers permanently straighten tightly curled hair; they work, but are linked to scalp burns, breakage and cancer associations still being investigated.