Nourishing masks work on the lipid side: oils and rich conditioning agents that smooth the cuticle and make hair softer and more pliable. That is a different job from hydration, which is about water.

Confusing the two is why some people mask diligently and see no improvement.

Nourishing versus hydrating

Nourishing — richer, oil-based, for hair that feels rough, brittle or straw-like. Adds substance.

Hydrating — lighter, humectant-based, for hair that feels dry but not coarse, and looks dull rather than rough.

The rough test: if your hair feels like straw, it wants nourishment. If it feels thin and lifeless and static-prone, it wants hydration. Coarse, dry, chemically treated hair usually wants both, alternated.

Who needs a nourishing mask

  • Coarse or thick hair, which is drier by structure
  • Curly and coily hair
  • Bleached or repeatedly coloured hair
  • Hair heat-styled several times a week
  • Long hair, where the ends are years old
  • Winter, when heated indoor air affects hair as well as skin

Who should be careful

  • Fine hair. Nourishing masks are heavy, and fine hair collapses under them. A volume or hydrating mask suits better
  • Oily scalps — keep it well away from the roots
  • Anyone whose hair already feels coated, which points to over-conditioning rather than a need for more

How often

Once a week for most hair that needs one.

Twice for bleached, very coarse or curly hair.

Every other week if your hair is only mildly dry.

Instead of your conditioner, not in addition to it.

The sign you are overdoing it

Hair that goes limp, feels slippery, will not hold a style, or looks flat and lifeless. That is over-conditioning, and the fix is fewer masks plus a clarifying wash — not a different mask.

Application

Damp not soaking hair, lengths and ends only, combed through, left the stated time, rinsed thoroughly. Warmth from a towel helps slightly; extra time does not.

Realistic expectations

Softer, smoother, easier to comb, less breakage. Not repaired split ends, and not restructured hair. Combine it with regular trims and less heat, which do the structural work a mask cannot.

For the range, see the hair mask guide.